{"id":52,"date":"2020-05-29T16:37:19","date_gmt":"2020-05-29T20:37:19","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/chapter\/lab-2-solar-energy-and-atmospheric-temperature\/"},"modified":"2023-01-26T14:22:46","modified_gmt":"2023-01-26T19:22:46","slug":"solar-energy-and-atmospheric-temperature","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/chapter\/solar-energy-and-atmospheric-temperature\/","title":{"raw":"Lab 02: Earth-Sun Relationships and Earth\u2019s Energy Budget","rendered":"Lab 02: Earth-Sun Relationships and Earth\u2019s Energy Budget"},"content":{"raw":"Most of Earth\u2019s energy comes from the sun. This energy is what drives the function of many Earth systems. Understanding how this energy makes its way to the Earth and interacts with the atmosphere and surface is a big part of understanding how the Earth works.\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Learning Objectives<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nAfter completion of this lab, you will be able to\r\n<ul>\r\n \t<li>Measure how Earth relates to the sun at different times of the year at different latitudes.<\/li>\r\n \t<li>Convert between several common temperature scales.<\/li>\r\n \t<li>Predict how temperature will generally change with latitude.<\/li>\r\n \t<li>Assess how local variables like cloud cover, aspect and surface albedo affect local radiation balance.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n<h1>Pre-Readings<\/h1>\r\nIn order to complete this lab, some background information on Earth-sun relationships, Earth\u2019s energy budget, common temperature scales, albedo, and aspect is required.\r\n<h2 style=\"text-align: left;\">Earth-Sun Relationships and Earth\u2019s Energy Budget<\/h2>\r\n<h3 style=\"text-align: left;\">Energy Inputs<\/h3>\r\nEarth is dependent on the sun\u2019s energy to support almost all of the systems at work. The actual amount of energy received at the Earth\u2019s surface at any specific location is dependent on three components:\r\n<ol>\r\n \t<li>The <strong>solar constant<\/strong> (approximately 1367 watts\/m<sup>2<\/sup>) is the amount of solar energy received at the top of the atmosphere. This changes slightly with solar output.<\/li>\r\n \t<li>The angle of the suns rays compared to the surface of the Earth. This changes with the seasons.<\/li>\r\n \t<li>Atmospheric composition. The state of the atmosphere - for example, how much water vapour is present above that location - is variable.<\/li>\r\n<\/ol>\r\nWe are all aware that the quantity of sunlight varies over time and space. Over a 24-hour period, we know that sunlight is generally strongest around noon and nonexistent during the time of day we call night. <strong>Insolation <\/strong>(incoming solar radiation) can be defined as the solar radiation or sunlight that is received by the Earth's ground surface or atmosphere. Many locations on our planet experience yearly variations in the quantity of insolation. If these variations are large enough, they contribute to the annual march of the seasons.\r\n<div class=\"textbox\">\r\n<p style=\"text-align: center;\"><strong>Reading: <a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Incoming-sunlight-NASA.pdf\">Incoming Sunlight [PDF]<\/a>\r\n<\/strong><\/p>\r\nThis short article explains how Earth\u2019s tilt and surface reflectivity impact how insolation behaves as it encounters the Earth. The same information is available on <a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page2.php\">the NASA Earth Observatory website.<\/a>\r\n\r\n<\/div>\r\nThe latitude at which the sun is directly overhead at noon is called the <strong>latitude of the subsolar point<\/strong>. The sun is directly overhead of the equator at noon on the equinoxes. It is directly overhead of the Tropic of Cancer at noon on the June solstice, and directly overhead of the Tropic of Capricorn at noon on the December solstice. In between these dates, you can determine the latitude of the subsolar point\u00a0using a diagram called the <strong>analemma\u00a0<\/strong>(<a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a>).\r\n\r\nReading the analemma is a three-step process:\r\n\r\n<strong>Step 1<\/strong>: On the figure-8 shape, find the date for which you want to know the latitude of the subsolar point.\r\n\r\n<strong>Step 2<\/strong>: Read across to the vertical axis on the left side of the analemma and read the latitude. <strong>Note: latitudes only go up to a maximum 23.5\u00b0, the latitude of the Tropic of Cancer and Capricorn, as the sun is never directly overhead at higher latitudes.<\/strong>\r\n\r\n<strong>Step 3<\/strong>: The analemma is split into the northern hemisphere (upper half, above 0\u00b0) and southern hemisphere (lower half, below 0\u00b0). Determine whether the latitude of the subsolar point is in the northern hemisphere or the southern hemisphere.<a id=\"figure2.1\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_1797\" align=\"aligncenter\" width=\"744\"]<img class=\"wp-image-1797 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2.png\" alt=\"image description linked in caption\" width=\"744\" height=\"1022\" \/> <strong>Figure 2.1.<\/strong> Analemma diagram. This diagram is used to determine the latitude of the subsolar point based on calendar date. <em>Source: Modified by A. Perkins and C. Welch, CC BY-NC-SA 4.0. Modified from US Coast and Geodetic Survey, Public Domain.<a class=\"internal\" href=\"#id2.1\">[Image description]<\/a><\/em>[\/caption]\r\n<h3 style=\"text-align: left;\">The March of the Seasons and the Angle of the Noon Sun<\/h3>\r\nAcross the range of latitudes, locations near the Equator receive high quantities of insolation all year long. Locations near the poles only receive significant amounts of insolation during a relatively short summer period. For this reason, localities near the poles have cold winter conditions during most of the year.\r\n<div class=\"textbox\">\r\n<p style=\"text-align: center;\"><strong>Reading: <a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Heat-Imbalances-NASA.pdf\">Heating Imbalances [PDF]<\/a><\/strong><\/p>\r\nThis short article describes how Earth\u2019s tilt and surface reflectivity impact heating imbalances across Earth and drive atmospheric and oceanic circulation on Earth. The same information is available on <a href=\"https:\/\/earthobservatory.nasa.gov\/Features\/EnergyBalance\/page3.php\">the NASA Earth Observatory website.<\/a>\r\n\r\n<\/div>\r\nThe angle at which solar radiation encounters the Earth\u2019s surface is important for how that energy is distributed. The <strong>angle of the noon sun (ANS)<\/strong> is calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a>:\r\n\r\n<a id=\"equation2.1\" class=\"internal\"><\/a><strong>\u00a0Equation 2.1<\/strong>\r\n\r\nANS = 90\u00b0 \u2212 (Latitude \u00b1 Latitude of the Subsolar Point)\r\n\r\nwhere\r\n<ul>\r\n \t<li>ANS = the angle of the noon sun (expressed in degrees)<\/li>\r\n \t<li>Latitude = the desired location on the surface of the Earth<\/li>\r\n \t<li>Latitude of the subsolar point (LSP) = the latitude where the sun is directly overhead for that date of the year.<\/li>\r\n<\/ul>\r\nExamples of how to calculate the difference between latitude for your location and the LSP are presented in <a class=\"internal\" href=\"#figure2.2\">Figure 2.2<\/a> for three scenarios. Important points to take note of:\r\n<ul>\r\n \t<li>You are interested in the total difference in latitude between our location and the LSP.<\/li>\r\n \t<li>You cannot have a sun angle greater than 90\u00b0.<\/li>\r\n \t<li>When determining whether you should add or subtract the LSP <strong>within Equation 2.1 specifically<\/strong>, consider which hemisphere you are in, and whether it is the \"summer half\" of the year (location is tilted towards the sun) or the \"winter half\" of the year (location is tilted away from the sun). If you are in the \"summer half\" of the year (i.e., approximately March 23 - September 20 in the Northern Hemisphere), then you subtract the LSP in Equation 2.1. If you are in the \"winter half\" of the year (i.e., approximately March 23 - September 20 in the Southern Hemisphere), then you add the LSP in Equation 2.1.\u00a0<a id=\"figure2.2\" class=\"internal\"><\/a><\/li>\r\n<\/ul>\r\n[caption id=\"attachment_1798\" align=\"aligncenter\" width=\"600\"]<img class=\"wp-image-1798\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example.png\" alt=\"\" width=\"600\" height=\"244\" \/> <strong>Figure 2.2.<\/strong> Scenarios for calculating angle of the noon sun, based on varying positions of latitude and LSP. In Scenario 1, you are in the Northern Hemisphere and it is the \"summer\" half of the year so you subtract the LSP. In Scenario 2, you are in the Northern Hemisphere and it is the \"winter\" half of the year so you add the LSP. In Scenario 3, you are in the Northern Hemisphere and it is the \"winter\" half of the year so you subtract the LSP. Because Scenario 3 is within 23.5 degree of the equator, you have to account for this by either flipping the location and LSP (when calculating the difference), or adding (180 - ) to the start of <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a>. S<em>ource: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]\r\n\r\nLet us assume that we are located at 49\u00b0 N on July 14. From the analemma in <a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a> we determine that the LSP is 21.5\u00b0 N. ANS may therefore be calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a> as:\r\n\r\n[latex]\\begin{array}{ll}\\text{ANS}&amp; = 90^{\\circ} - (\\text{Latitude}-\\text{Latitude of the Subsolar Point}) \\\\ &amp;= 90^{\\circ} - (49^{\\circ} - 21.5^{\\circ}) = 62.5^{\\circ}\\end{array}[\/latex]\r\n\r\nWhen sunlight impacts the Earth\u2019s surface at an oblique angle, the insolation is stretched over a greater area, reducing its <strong>intensity <\/strong>(<a class=\"internal\" href=\"#figure2.3\">Figure 2.3<\/a>).<a id=\"figure2.3\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_40\" align=\"aligncenter\" width=\"650\"]<img class=\"wp-image-40\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle.png\" alt=\"When sunlight 1 metre wide hits the Earth at a 90 degree angle, it hits 1 m of ground. When sunlight 1 metre wide hits the Earth at a 45 degree angle, it hits 1.4 m of ground, which is a 40% increase in area covered by the same sunlight. This decreases the intensity of sunlight that hits each point on the Earth\u2019s surface.\" width=\"650\" height=\"369\" \/> <strong>Figure 2.3<\/strong>. Reduction in solar intensity as sunlight encounters the Earth\u2019s surface at an oblique angle. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]\r\n\r\nWe can extend the ANS calculation to also look at the effect angle of incidence has on insolation intensity using <a class=\"internal\" href=\"#equation2.2\">Equation 2.2<\/a>:\r\n\r\n<strong><a id=\"equation2.2\" class=\"internal\"><\/a>Equation 2.2<\/strong>\r\n\r\n[latex]\\text{Intensity} = sin(\\text{ANS})[\/latex]\r\n\r\nThis is a unitless value for intensity between 0 and 1, that can be multiplied by 100 to yield a percentage of the 100% intensity currently experienced at the latitude of the subsolar point.\r\n\r\nFor example, at 49\u00b0 N on July 14, and using the ANS calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a> above, the solar intensity (<a class=\"internal\" href=\"#equation2.2\">Equation 2.2<\/a>) would be:\r\n\r\n[latex]\\text{Intensity} = sin(62.5^{\\circ}) = 0.89\\text{ or } 0.89\\times 100\\% = 89\\%[\/latex]\r\n<div>\r\n\r\n<a class=\"internal\" href=\"#figure2.4\">Figure 2.4<\/a> presents a summary of incoming solar radiation for July 14 at 49\u00b0 N latitude. A line has been drawn on a protractor to demonstrate the incoming angle of solar radiation (ANS = 62.5\u00b0). This corresponds to a relative intensity of 0.89 or 89%.<a id=\"figure2.4\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_1799\" align=\"aligncenter\" width=\"600\"]<img class=\"wp-image-1799\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower.png\" alt=\"\" width=\"600\" height=\"185\" \/> <strong>Figure 2.4.<\/strong> Incoming solar radiation on July 14 at 49\u00b0 latitude (Eiffel Tower). The angle of the noon sun (ANS) is depicted on the protractor (left) and expressed as a value in the box (right). Relative intensity of solar radiation is also shown on the right as a unitless value (0.89). This could also be expressed as 89%. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]\r\n<h3 style=\"text-align: left;\">Earth's Energy Budget<\/h3>\r\nIn order to maintain a stable climate over long periods of time, the energy inputs to Earth (insolation) must be balance by energy outputs, radiated as heat. This balance is also known as Earth's energy budget. On average,\r\n<ul>\r\n \t<li>23% of energy is absorbed in the atmosphere by gases, dust, and other particles,<\/li>\r\n \t<li>48% of energy is absorbed at the surface, and<\/li>\r\n \t<li>29% of energy is reflected directly back to space by clouds, particles, or bright ground surfaces such as ice (<a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page4.php\">NASA Earth Observatory (1), 2009<\/a>).<\/li>\r\n<\/ul>\r\nAs we can see from these percentages, the surface of Earth and the surrounding atmosphere play different roles in energy absorption and loss. Most energy is absorbed at the surface, while most energy is radiated back to space from the atmosphere.\r\n\r\nAs noted above, approximately 48% of incoming solar radiation is absorbed at the surface. This energy is returned to the atmosphere through three processes:\r\n<ol>\r\n \t<li>25% through <strong>evaporation<\/strong>, i.e., turning liquid water into water vapour,<\/li>\r\n \t<li>5% through <strong>convection<\/strong>, i.e., air warming in contact with the ground and rising, and<\/li>\r\n \t<li>net 17% as infrared thermal energy (heat) (<a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page5.php\"><span style=\"background-color: #ffffff;\">NASA Earth Observatory (2), 2009<\/span><\/a>).<\/li>\r\n<\/ol>\r\n<h2 style=\"text-align: left;\">Global Temperature Distribution and Common Temperature Scales<\/h2>\r\nBased on what you now know about how the sun\u2019s energy is distributed around the globe, it should make sense that incoming solar radiation is unequally received at the Earth\u2019s surface. One of the easiest ways to see this is by examining average temperatures by latitude.\r\n\r\nThe three maps at the links below show global surface temperatures at the two solstice positions and at the equinox. Surface temperatures are displayed as colour, with red indicating hotter temperatures and blues and purples indicating colder temperatures. You can view the complete temperature scale by clicking on the hamburger menu in the bottom-left corner of the screen. What do you notice about latitudinal changes in temperature as you move from the equator to the poles? You can click anywhere on the map to get a temperature reading for that location.\r\n\r\n<a href=\"https:\/\/earth.nullschool.net\/#2020\/06\/21\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">June Solstice<\/a>\r\n\r\n<a href=\"https:\/\/earth.nullschool.net\/#2019\/12\/20\/0800Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">December Solstice<\/a>\r\n\r\n<a href=\"https:\/\/earth.nullschool.net\/#2020\/03\/20\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">Equinox<\/a>\r\n\r\nTemperature is a measure of the average kinetic energy of a substance. It is a way of measuring heat energy, as heat always flows from material at a high temperature to material at a lower temperature, raising the temperature of the cooler material. There are three temperature scales that are commonly used: Celsius (\u00b0C), Fahrenheit (\u00b0F), and Kelvin (K). Most of the world (including most of the scientific world) uses the Celsius scale for measurement and reporting.\r\n\r\nThe following formulas allow you to convert between these scales.\r\n\r\n<strong><a id=\"equation2.3\" class=\"internal\"><\/a>Equation 2.3.<\/strong> Convert from Fahrenheit to Celsius:\r\n\r\n[latex]T{(^{\\circ} C)} = \\dfrac {5}{9} \\times \\left( T{(^{\\circ} F)} - 32 \\right)[\/latex]\r\n\r\n<a id=\"equation2.4\" class=\"internal\"><\/a><strong>Equation 2.4.<\/strong> Convert from Celsius to Fahrenheit:\r\n\r\n[latex]T{(^{\\circ} F)} = \\left( \\dfrac {9}{5} \\times T{(^{\\circ} C)} \\right) + 32[\/latex]\r\n\r\n<strong><a id=\"equation2.5\" class=\"internal\"><\/a>Equation 2.5.<\/strong> Convert from Kelvin to Celsius:\r\n\r\n<\/div>\r\n[latex]T{(^{\\circ} C)} = T(K) - 273[\/latex]\r\n\r\n<a id=\"equation2.6\" class=\"internal\"><\/a><strong>Equation 2.6.<\/strong> Convert from Celsius to Kelvin:\r\n\r\n[latex]T(K) = T{(^{\\circ} C)} + 273[\/latex]\r\n\r\nwhere\r\n<ul>\r\n \t<li style=\"text-align: left;\">T (\u00b0C) = Temperature in degrees Celsius<\/li>\r\n \t<li style=\"text-align: left;\">T (\u00b0F) = Temperature in degrees Fahrenheit<\/li>\r\n \t<li style=\"text-align: left;\">T (K) = Temperature in Kelvin<\/li>\r\n<\/ul>\r\n<h2 style=\"text-align: left;\">Temperature Gradients<\/h2>\r\nA gradient is the rate of change for a value over a given distance. It can be useful for many environmental variables like imaging how topography changes over space or how temperature varies vertically or horizontally through the atmosphere.\r\n\r\nTemperature changes along a gradient through the atmosphere are called <strong>lapse rates<\/strong>.\u00a0Lapse rates can be calculated using <a class=\"internal\" href=\"#equation2.7\">Equation 2.7<\/a>:\r\n\r\n<strong><a id=\"equation2.7\" class=\"internal\"><\/a>Equation 2.7<\/strong>\r\n\r\n[latex]\\text{Lapse rate} (^{\\circ} C\/km) = -1 \\left( \\dfrac{\\Delta T}{\\Delta z} \\right) = -1 \\left( \\dfrac{T_{2} - T_{1}}{z_{2} - z_{1}} \\right)[\/latex]\r\n\r\nwhere\r\n<ul>\r\n \t<li>\u0394 = delta symbol, represents the <strong>change<\/strong> in the variable it precedes (for example, the change in temperature)<\/li>\r\n \t<li>T = air temperature (normally in \u00b0C)<\/li>\r\n \t<li>z = altitude (normally in km). This term can be replaced with distance if calculating a horizontal temperature gradient<\/li>\r\n \t<li>T<sub>1<\/sub> , z<sub>1 <\/sub>= the measurement taken at the lower point in the atmosphere<\/li>\r\n<\/ul>\r\nFor example, let\u2019s say you wanted to know the lapse rate between the two temperature readings in the atmosphere shown on Figure 2.5.<a id=\"figure2.5\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_42\" align=\"aligncenter\" width=\"500\"]<img class=\"wp-image-42\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations.png\" alt=\"Scatter plot with altitude in Kilometres on the y-axis and temperature in Celsius on the x-axis. Measurement 1 was 10 degrees Celsius at 2 km altitude and measurement 2 was \u2013 30 degrees Celsius at 8 km altitude.\" width=\"500\" height=\"366\" \/> <strong>Figure 2.5.<\/strong> Altitude (z) and temperature (T) of two measurement locations used to calculate lapse rate. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]\r\n\r\nWe can read the required values from <a class=\"internal\" href=\"#figure2.5\">Figure 2.5<\/a>: T<sub>1<\/sub> is 10\u00b0C at z<sub>1<\/sub> of 2 km, and T<sub>2<\/sub> is \u221230\u00b0 at z<sub>2<\/sub> of 8 km. Hence, the lapse rate is calculated using <a class=\"internal\" href=\"#equation2.7\">Equation 2.7<\/a> as:\r\n\r\n[latex]\\begin{array}{ll}\\text{Lapse rate} (^{\\circ} C\/km)&amp; = -1 \\left( \\dfrac{\\Delta T}{\\Delta z} \\right) = -1 \\left( \\dfrac{T_{2} - T_{1}}{z_{2} - z_{1}} \\right)\\\\&amp;= -1 \\left( \\dfrac{-30^{\\circ} C - 10^{\\circ} C}{8km - 2km} \\right) = -1 \\left( \\dfrac{-40^{\\circ} C}{6km} \\right) = 6.6^{\\circ} C\/km\\end{array}[\/latex]\r\n\r\nNotice that the lapse rate above has a positive value. This means that based on the series in which the measurements were taken, the temperature is decreasing as the altitude increases, which is the normal condition in the troposphere.\r\n<h2 style=\"text-align: left;\">Albedo and Aspect<\/h2>\r\nLocal variations in surface reflectivity, called <strong>albedo<\/strong>, and the direction a surface faces, its <strong>aspect<\/strong>, can have a major influence on that surface's absorption and retention of solar radiation.\r\n\r\n<strong>Albedo<\/strong> is measured as the percentage of radiation reflected from a surface (Figure 2.6). High albedo surfaces have a high reflectivity. Surfaces like ice are highly reflective and absorb very little incoming solar radiation. Surfaces like asphalt and concrete have a very low reflectivity and absorb significant amounts of incoming solar radiation (Figure 2.6). This difference in albedo leads to significant differences in heating. In the atmosphere, clouds have a very high albedo and reflect energy, whereas particulate matter has a low albedo and absorbs energy.<a id=\"figure2.6\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_1800\" align=\"aligncenter\" width=\"2524\"]<img class=\"wp-image-1800 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo.png\" alt=\"image description linked to in caption\" width=\"2524\" height=\"1596\" \/> <strong>Figure 2.6.<\/strong> Albedo of common surfaces.\u00a0<em>Source: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Albedo-e_hg.png\">H. Grobe (2000) <\/a>CC BY-SA 2.5. <\/em><strong>B:<\/strong> Pictorial demonstration of how albedo controls reflection and absorption of energy received from the sun. <em>Source:\u00a0<a href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0213368\">Prevedello et al (2019)<\/a>. CC BY.<\/em> <a class=\"internal\" href=\"#id2.6\">[Image description]<\/a>[\/caption]<strong>Aspect<\/strong> refers to the direction a topographic slope is facing (<a class=\"internal\" href=\"#figure2.7\">Figure 2.7<\/a>). We refer to direction based on the cardinal points of a compass. A southerly aspect means that the topographic slope is facing to the south. In the mid latitudes of the northern hemisphere, a southerly aspect means that a slope is tilted towards incoming solar radiation (based on angle of the noon sun). A northerly aspect in the same location would mean that the slope is tilted away from incoming solar radiation.<a id=\"figure2.7\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_1801\" align=\"aligncenter\" width=\"2713\"]<img class=\"wp-image-1801 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2.png\" alt=\"\" width=\"2713\" height=\"1127\" \/> <strong>Figure 2.7. <\/strong>Cardinal directions on the compass. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em> <strong>B:<\/strong> An illustration of the concept of aspect in the northern hemisphere. The slope labelled with a yellow star has a north-facing aspect in the image, whereas the slope labelled with the pink square has a south-facing aspect. <em>Modified after <a href=\"https:\/\/tc.copernicus.org\/articles\/13\/29\/2019\/\">Olsen &amp; Rupper (2019)<\/a> CC BY.<\/em>[\/caption]\r\n<h1>Lab Exercises<\/h1>\r\nIn this lab you will explore how Earth-Sun relationships generate latitudinal and seasonal differences in temperature, and the foundations for Earth\u2019s radiation budget. You will use several online maps and interactive websites to complete this exercise.\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EX1: Earth-Sun Relationships and Earth's Energy Budget<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ol>\r\n \t<li>According to the NASA article you read (<a style=\"text-align: initial; font-size: 1em;\" href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Incoming-sunlight-NASA.pdf\" rel=\"noopener\">Incoming Sunlight [PDF]<\/a>), day and night, averaged around the globe, how much energy reaches the Earth from the sun?<\/li>\r\n \t<li>The above number describes an <strong>average <\/strong>value across the Earth. Describe the three factors that determine the <strong>actual <\/strong>amount of radiation received at the Earth\u2019s surface at a specific location.<\/li>\r\n<\/ol>\r\nThe solar constant measures the approximate solar radiation received at the top of the atmosphere. However, at various times throughout the year, certain latitudes tilt towards or away from the sun, based on Earth\u2019s orbit. For example, in December, the northern hemisphere is tilted away from the sun, whereas in July, the southern hemisphere is tilted away from the sun.\r\n\r\nOpen <a href=\"https:\/\/cimss.ssec.wisc.edu\/wxfest\/SunAngle\/sunangle.html\">Explore the Effect of the Angle of Incidence on the Sun's Energy Interactive Diagram<\/a> to answer questions 3 and 4. <strong>Note this interactive is simplified to only communicate changes in radiation based on sun angle and does not include the influence of the atmosphere on incoming solar radiation.<\/strong>\r\n<ol start=\"3\">\r\n \t<li>Set the month in the box at the bottom of the interactive to \u201cMarch.\u201d Explain how the amount of solar radiation received at Earth\u2019s surface changes as you move from the equator to the north pole.<\/li>\r\n \t<li>Now let's see how this changes throughout the year. To get the values you need, cycle through the four months in the box at the bottom of the interactive.\r\n<ol type=\"a\">\r\n \t<li>Record the actual amount of radiation received at Earth\u2019s surface for three latitudes: Equator, Tropic of Cancer and the North Pole in <a class=\"internal\" href=\"#table2.1\">Table 2.1<\/a>. This table is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.\r\n<table class=\"grid aligncenter\" style=\"border-collapse: collapse; width: 50%;\" border=\"0\"><caption><a id=\"table2.1\" class=\"internal\"><\/a>Table 2.1. Actual amount of radiation received at Earth's surface on the equinoxes and solstices at three locations.<\/caption>\r\n<tbody>\r\n<tr>\r\n<th scope=\"col\">Month<\/th>\r\n<th scope=\"col\">Equator<\/th>\r\n<th scope=\"col\">Tropic of Cancer<\/th>\r\n<th scope=\"col\">North Pole<\/th>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 20%;\">March<\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 20%;\">June<\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 20%;\">September<\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 20%;\">December<\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<td style=\"width: 20%;\"><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/li>\r\n \t<li>Graph the points for each month on <a class=\"internal\" href=\"#figure2.8\">Figure 2.8<\/a>, connecting each with lines. Use different symbols for each line and include a legend to reference the symbols. This graph is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.<a id=\"figure2.8\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_45\" align=\"aligncenter\" width=\"650\"]<img class=\"wp-image-45\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8.png\" alt=\"\" width=\"650\" height=\"460\" \/> <strong>Figure 2.8.<\/strong> Change in energy received at Earth's surface through time. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\nUse the analemma (<a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a>) to answer questions 5 and 6:\r\n<ol start=\"5\">\r\n \t<li>At what latitude is the Sun directly overhead on your birthday? Record the date and the latitude of the subsolar point.<\/li>\r\n \t<li>Earth Day is celebrated on April 22nd every year. At what latitude is the sun directly overhead on this date?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EX2: The March of the Seasons and the Angle of the Noon Sun<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nThe latitude at which the Sun is directly overhead may be helpful in understanding overall Sun patterns, but let's say you want to set up a solar panel at your house. You need to know the sun angle for your location on a specific date so that you can setup your solar panel for optimal effectiveness.\r\n<ol start=\"7\">\r\n \t<li>Complete the following calculations for angle of the noon sun (ANS) and relative solar intensity (Intensity, expressed as a percentage). Draw the angle on the figures provided. Show your working. These figures are also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.\r\n<ol type=\"a\">\r\n \t<li>On Oct. 3rd, if you are located at 0\u00b0 latitude.\r\n<table class=\"grid aligncenter\">\r\n<tbody>\r\n<tr>\r\n<td rowspan=\"2\"><strong><img class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" \/>\r\n<\/strong><\/td>\r\n<th scope=\"col\">Angle of Noon Sun<\/th>\r\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/li>\r\n \t<li>On April 2nd, if you are located at 61\u00b0 North latitude.\r\n<table class=\"grid aligncenter\">\r\n<tbody>\r\n<tr>\r\n<td rowspan=\"2\"><strong><img class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" \/>\r\n<\/strong><\/td>\r\n<th scope=\"col\">Angle of Noon Sun<\/th>\r\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/li>\r\n \t<li>On Dec. 9th, if you are located at 85\u00b0 North latitude.\r\n<table class=\"grid aligncenter\">\r\n<tbody>\r\n<tr>\r\n<td rowspan=\"2\"><strong><img class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" \/>\r\n<\/strong><\/td>\r\n<th scope=\"col\">Angle of Noon Sun<\/th>\r\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\r\n<\/tr>\r\n<tr>\r\n<td><\/td>\r\n<td><\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t<li>It's August 1st and you are climbing up the south facing slope of Mount Denali in Alaska (the highest peak in North America). At noon you come across another climber in distress and need to contact emergency services for a helicopter rescue, but your satellite phone battery is dead. Quickly you remember that you have a portable solar panel charger in your backpack. You unpack it and plug it in to the phone. It begins to charge, but very slowly. You decide to speed up the charge by setting up the solar panel at an angle.<\/li>\r\n<\/ol>\r\n<p style=\"padding-left: 40px;\">At what angle should you set the solar panel to take the best advantage of the incoming solar radiation? <strong>Show all relevant calculations.<\/strong> <a class=\"internal\" href=\"#figure2.9\">Figure 2.9<\/a> is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.<a id=\"figure2.9\" class=\"internal\"><\/a><\/p>\r\n\r\n\r\n[caption id=\"attachment_47\" align=\"aligncenter\" width=\"442\"]<img class=\"wp-image-47\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle.png\" alt=\"Solar panel raised above ground at unknown angle.\" width=\"442\" height=\"355\" \/> <strong>Figure 2.9.<\/strong> Schematic of solar panel. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em>[\/caption]\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EX3: Global Temperature Distribution and Common Temperature Scales<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nSeasonality and Sun angle is just one way incoming solar radiation can vary for a specific location. Using satellite measurements it is possible to get a sense of how cloud cover affects incoming solar radiation.\r\n\r\nThis <a href=\"https:\/\/www.ssec.wisc.edu\/~tomw\/ams\/amsimage.html\">Satellite Temperature Data website<\/a> displays temperature data collected by a satellite looking through the atmosphere from above. It calculates the temperature from the reflective surface in the image.\r\n<ol start=\"9\">\r\n \t<li>Choose a location on the map where you can see a cloudless area near the coast. Compare the land and ocean temperatures at this latitude. Is there a difference between the temperatures? Explain why this is the case.<\/li>\r\n \t<li>Now compare the temperatures in the previous question with the temperature measurement at the top of a nearby cloud.\r\n<ol type=\"a\">\r\n \t<li>Is the temperature at the top of the cloud higher or lower than the land and water surfaces?<\/li>\r\n \t<li>What does this tell you about how energy radiated from the Earth\u2019s surface is affected as it interacts with clouds in the atmosphere on its way out to space?<\/li>\r\n \t<li>Assume the top of the cloud is at the top of the troposphere, 18 km above the land surface for your location. Calculate the lapse rate between the Earth\u2019s land surface and the top of the cloud. Show your work.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n\r\n<hr \/>\r\n\r\nOn April 10, 1912 the steamship Titanic left Southampton England on its maiden voyage across the Atlantic Ocean to New York (<a class=\"internal\" href=\"#figure2.10\">Figure 2.10<\/a>). By the evening of April 15, the Titanic was sinking in the middle of the Atlantic Ocean, after striking an iceberg. The Titanic sank in the cold waters of the northern Atlantic.<a id=\"figure2.10\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_754\" align=\"aligncenter\" width=\"2560\"]<img class=\"wp-image-754 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.10-Titanic-in-Cork-Harbour-scaled-1.jpg\" alt=\"\" width=\"2560\" height=\"1149\" \/> <strong>Figure 2.10.<\/strong> Titanic on its maiden voyage, off the coast of Ireland (Photo taken on April 11, 1912). <em>Source: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Titanic-Cobh-Harbour-1912.JPG\">Cobh Heritage Centre, Public Domain<\/a>.<\/em>[\/caption]\r\n<ol start=\"11\">\r\n \t<li>The surface temperature when the Titanic left Southampton, England was 53.1 \u00b0F. Convert this temperature to \u00b0C.<\/li>\r\n \t<li>The average daily maximum temperature for Southampton, England in April 1912 was 288.5 K. Was the temperature when the Titanic left higher or lower than this average?<\/li>\r\n \t<li>The city of Calgary, Alberta is located at a similar latitude to the city of Southampton, England. In April 1912, the average daily maximum temperature in Calgary was 5.5 \u00b0C. Explain the physical geography surrounding why this temperature is so different than the average daily maximum temperature in Southampton. Hint: you may need to look at a map of where Calgary is located relative to where Southampton is.<\/li>\r\n<\/ol>\r\nThe Titanic sailed in April, between the extreme conditions of summer and winter. Consult the global temperature maps below for an example of January and July temperatures:\r\n<ul>\r\n \t<li style=\"text-align: left;\"><a href=\"https:\/\/earth.nullschool.net\/#2019\/07\/15\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">July Temperatures<\/a><\/li>\r\n \t<li style=\"text-align: left;\"><a href=\"https:\/\/earth.nullschool.net\/#2020\/01\/01\/0800Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">January Temperatures<\/a><\/li>\r\n<\/ul>\r\nRecall that the maps show temperature displayed as colour: reds indicate hotter temperatures and blues to purples indicate colder temperatures. So, all locations with the same colour will have similar temperatures. You can click anywhere on the map to get a temperature reading for that location.\r\n<ol start=\"14\">\r\n \t<li>Is the temperature contrast between the equator and the Arctic region greatest in winter or summer for the northern hemisphere?<\/li>\r\n \t<li>If latitude were the only control on temperature, the colour bands indicating similar temperatures should run straight across the map from east to west.\r\n<ol type=\"a\">\r\n \t<li>Identify one area on the map where this occurs. Use your knowledge of place names or use an atlas or <a href=\"https:\/\/www.google.com\/earth\/index.html\">Google Earth<\/a> to determine the name of the location you identified.<\/li>\r\n \t<li>What physical geography conditions explain why the temperatures follow this pattern in the place you identified?<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t<li>Compare the January and July maps temperature maps.\r\n<ol type=\"a\">\r\n \t<li>Describe one area of the world that exhibits a large annual temperature range.<\/li>\r\n \t<li>What physical geography conditions explain the large annual temperature range for the place you identified?<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t<li>The atmospheric conditions on the night of April 15, 1912 were clear, that is, there was no cloud cover. How do you think the lack of clouds that night affected the air temperature, according to what we know about local energy budget and how clouds interact with radiation?<\/li>\r\n \t<li>The last emergency communication from the Titanic before it sank gave its position at the following coordinates: 41\u02da 46\u2019 N, 50\u02da 14\u2019 W. Go back to the <a href=\"https:\/\/www.ssec.wisc.edu\/~tomw\/ams\/amsimage.html\">Satellite Temperature Data website<\/a>. Find some open water in the Atlantic Ocean at a latitude of around 41\u00b0N.\r\n<ol type=\"a\">\r\n \t<li>Record the surface water temperature in \u00b0C.<\/li>\r\n \t<li>Survival rates for humans in specific water temperatures are given in <a class=\"internal\" href=\"#table2.2\">Table 2.2<\/a>. Based on the water temperature you obtained in part a, how long would an individual have been able to survive in open water after abandoning the Titanic?\r\n<table class=\"grid aligncenter\" style=\"width: 40%;\"><caption><a id=\"table2.2\" class=\"internal\"><\/a>Table 2.2. Expected time of survival for humans in specific water temperatures.<\/caption>\r\n<tbody>\r\n<tr>\r\n<th scope=\"col\">Water Temperature (\u00b0F)<\/th>\r\n<th scope=\"col\">Expected Time of Survival<\/th>\r\n<\/tr>\r\n<tr>\r\n<td>32.5\u00b0<\/td>\r\n<td>45 minutes<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>32.5\u201340\u00b0<\/td>\r\n<td>30 \u2013 90 minutes<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>40\u201350\u00b0<\/td>\r\n<td>1 \u2013 3 hours<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>50\u201360\u00b0<\/td>\r\n<td>1 \u2013 6 hours<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>60\u201370\u00b0<\/td>\r\n<td>2 \u2013 40 hours<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>70\u201380\u00b0<\/td>\r\n<td>3 hours \u2013 indefinite<\/td>\r\n<\/tr>\r\n<tr>\r\n<td>&gt; 80\u00b0<\/td>\r\n<td>Indefinite<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EX4: Lapse Rates<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nSeveral distress rockets were fired into the air to alert nearby ships of the Titanic\u2019s position and to aid in the rescue effort. Standard temperature values for different layers of the atmosphere are presented in <a class=\"internal\" href=\"#table2.3\">Table 2.3<\/a>.\r\n<table class=\"grid aligncenter\" style=\"height: 96px; width: 75%;\"><caption><a id=\"table2.3\" class=\"internal\"><\/a>Table 2.3. Standard atmospheric temperature at specific points in the atmosphere.<\/caption>\r\n<tbody>\r\n<tr style=\"height: 16px;\">\r\n<th scope=\"col\">Atmospheric layer<\/th>\r\n<th scope=\"col\">Altitude (km)<\/th>\r\n<th scope=\"col\">Temperature (\u00b0C)<\/th>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"height: 16px; width: 221.883px;\">Surface (Northern hemisphere)<\/td>\r\n<td style=\"height: 16px; width: 104.45px;\">Sea level (0)<\/td>\r\n<td style=\"height: 16px; width: 136.567px;\">15<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"height: 16px; width: 221.883px;\">Tropopause<\/td>\r\n<td style=\"height: 16px; width: 104.45px;\">18<\/td>\r\n<td style=\"height: 16px; width: 136.567px;\">-57<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"height: 16px; width: 221.883px;\">Stratopause<\/td>\r\n<td style=\"height: 16px; width: 104.45px;\">50<\/td>\r\n<td style=\"height: 16px; width: 136.567px;\">0<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"height: 16px; width: 221.883px;\">Mesopause<\/td>\r\n<td style=\"height: 16px; width: 104.45px;\">80<\/td>\r\n<td style=\"height: 16px; width: 136.567px;\">-90<\/td>\r\n<\/tr>\r\n<tr style=\"height: 16px;\">\r\n<td style=\"height: 16px; width: 221.883px;\">Thermopause<\/td>\r\n<td style=\"height: 16px; width: 104.45px;\">480<\/td>\r\n<td style=\"height: 16px; width: 136.567px;\">1200<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<ol start=\"19\">\r\n \t<li>Plot the standard atmospheric temperature values presented in <a class=\"internal\" href=\"#table2.3\">Table 2.3<\/a> on the Exercise 4: Temperature Gradients Graph (provided in the <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a>). Connect the points with a line and label the troposphere, stratosphere, mesophere and thermosphere.<\/li>\r\n \t<li>The distress rockets passed through the lowest part of the atmosphere. Calculate the lapse rate in the lowest 10 km of the troposphere from the graph you created.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">EX5: Albedo and Aspect<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nTake a look at the glaciers that cover Mount Rainier, a stratovolcano in Washington, USA in <a class=\"internal\" href=\"#figure2.11\">Figure 2.11<\/a>, and use it to answer the questions that follow.<a id=\"figure2.11\" class=\"internal\"><\/a>\r\n\r\n[caption id=\"attachment_49\" align=\"aligncenter\" width=\"1376\"]<img class=\"wp-image-49 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier.png\" alt=\" aerial perspective of Mount Rainier and its glaciers. The glaciers radiate from the centre of the mountain peak in all directions. Glaciers on some sides appear larger and longer than others. The glaciers are separated by rocky terrain.\" width=\"1376\" height=\"1348\" \/> <strong>Figure 2.11.<\/strong> Mount Rainier, WA glacier coverage. The yellow star in the map inset shows where Mount Rainier is located in North America. <em>Source: <a href=\"https:\/\/www.usgs.gov\/media\/images\/glaciers-mount-rainier-overlaid-a-base-map-lidar-image-which\">Tom Sisson, USGS, Public Domain<\/a>.<\/em>[\/caption]\r\n<ol start=\"21\">\r\n \t<li>Mount Rainier contains the greatest amount of glacier ice of any mountain in the lower 48 United States.\r\n<ol type=\"a\">\r\n \t<li>Do you think aspect has a role in controlling the distribution and size of glaciers around the central peak of Mount Rainier? Explain your answer.<\/li>\r\n \t<li>Choose three different glaciers from different locations around the main peak. Compare their aspect and relative size.<\/li>\r\n<\/ol>\r\n<\/li>\r\n \t<li>The zones in between the glaciers are covered mostly in bare rock and light forested vegetation.\r\n<ol type=\"a\">\r\n \t<li>How do you think the albedo differences between the middle of the glacier and the locations between the glaciers affects how the glacier melts?<\/li>\r\n \t<li>As the glacier melts further back, more sediment and bare rock is revealed. Do you think this negatively or positively reinforces the melt rate of the glacier? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--key-takeaways\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Reflection Questions<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n<ol>\r\n \t<li>Imagine if Earth was not tilted 23.5\u00b0 on its axis, but instead had no tilt. How would this affect Earth\u2019s energy budget?<\/li>\r\n \t<li>If the Titanic had sunk on a cloudy night, how would that have affected air temperature conditions and potential survivability for those who had to abandon the ship as it sunk?<\/li>\r\n \t<li>The southern hemisphere is about 81% water at the surface, whereas the northern hemisphere is about 61% water how do you think this difference affects the local energy budget for these two different hemispheres?<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n<h1><a id=\"lab2worksheets\" class=\"internal\"><\/a>Worksheets<\/h1>\r\n<a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.docx\">Lab 02 Student Workbook [Word]<\/a>\r\n\r\n<a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.odt\">Lab 02 Student Workbook [ODT]<\/a>\r\n\r\n<a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.pdf\">Lab 02 Student Workbook [PDF]<\/a>\r\n<h1>References<\/h1>\r\n<p class=\"hanging-indent\">Prevedello, J.A., Winck, G.R., Weber, M.M., Nichols, E., &amp; Sinervo, B. (2019) Impacts of forestation and deforestation on local temperature across the globe. <em>PLoS ONE, 14<\/em>(3). https:\/\/doi.org\/10.1371\/journal.pone.0213368<\/p>\r\n<p class=\"hanging-indent\">Olson, M. &amp; Rupper, S. (2019) Impacts of topographic shading on direct solar radiation for valley glaciers in complex topography, <em>The Cryosphere<\/em>, 13, 29\u201340. https:\/\/doi.org\/10.5194\/tc-13-29-2019.<\/p>\r\n\r\n<h3>Image Descriptions<\/h3>\r\n<strong><a id=\"id2.1\" class=\"internal\"><\/a>Figure 2.1. Analemma diagram<\/strong>\r\n\r\nThe diagram shows an Analemma, a graph that demonstrates the latitude where the sun is directly overhead for different days of the year. For example, on the equinox dates it is directly overhead at the equator. The shape of the graph is in a figure-eight. The dates are shown on the figure-eight portion of the diagram and the latitudes are written on the y-axis.\r\n\r\n<a class=\"internal\" href=\"#figure2.1\">[Return to Figure 2.1]<\/a>\r\n\r\n<strong><a id=\"id2.6\" class=\"internal\"><\/a>Figure 2.6. Albedo of common surfaces.<\/strong>\r\n\r\nIn part A) of the figure there is a table that shows different materials and their associated albedo measured as percent reflectivity. Water is at the bottom of the scale, with a low albedo and percentage of reflectivity and snow and ice are on the high end of the scale with a high albedo and percentage reflectivity. In part B) there is an image of two different land surfaces, the left side showing a highly vegetated surface that absorbs significant solar energy with low reflection, and the right side showing a bare land surface with significant reflection and high albedo.\r\n\r\n<a class=\"internal\" href=\"#figure2.6\">[Return to Figure 2.6]<\/a>","rendered":"<p>Most of Earth\u2019s energy comes from the sun. This energy is what drives the function of many Earth systems. Understanding how this energy makes its way to the Earth and interacts with the atmosphere and surface is a big part of understanding how the Earth works.<\/p>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Learning Objectives<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>After completion of this lab, you will be able to<\/p>\n<ul>\n<li>Measure how Earth relates to the sun at different times of the year at different latitudes.<\/li>\n<li>Convert between several common temperature scales.<\/li>\n<li>Predict how temperature will generally change with latitude.<\/li>\n<li>Assess how local variables like cloud cover, aspect and surface albedo affect local radiation balance.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<h1>Pre-Readings<\/h1>\n<p>In order to complete this lab, some background information on Earth-sun relationships, Earth\u2019s energy budget, common temperature scales, albedo, and aspect is required.<\/p>\n<h2 style=\"text-align: left;\">Earth-Sun Relationships and Earth\u2019s Energy Budget<\/h2>\n<h3 style=\"text-align: left;\">Energy Inputs<\/h3>\n<p>Earth is dependent on the sun\u2019s energy to support almost all of the systems at work. The actual amount of energy received at the Earth\u2019s surface at any specific location is dependent on three components:<\/p>\n<ol>\n<li>The <strong>solar constant<\/strong> (approximately 1367 watts\/m<sup>2<\/sup>) is the amount of solar energy received at the top of the atmosphere. This changes slightly with solar output.<\/li>\n<li>The angle of the suns rays compared to the surface of the Earth. This changes with the seasons.<\/li>\n<li>Atmospheric composition. The state of the atmosphere &#8211; for example, how much water vapour is present above that location &#8211; is variable.<\/li>\n<\/ol>\n<p>We are all aware that the quantity of sunlight varies over time and space. Over a 24-hour period, we know that sunlight is generally strongest around noon and nonexistent during the time of day we call night. <strong>Insolation <\/strong>(incoming solar radiation) can be defined as the solar radiation or sunlight that is received by the Earth&#8217;s ground surface or atmosphere. Many locations on our planet experience yearly variations in the quantity of insolation. If these variations are large enough, they contribute to the annual march of the seasons.<\/p>\n<div class=\"textbox\">\n<p style=\"text-align: center;\"><strong>Reading: <a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Incoming-sunlight-NASA.pdf\">Incoming Sunlight [PDF]<\/a><br \/>\n<\/strong><\/p>\n<p>This short article explains how Earth\u2019s tilt and surface reflectivity impact how insolation behaves as it encounters the Earth. The same information is available on <a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page2.php\">the NASA Earth Observatory website.<\/a><\/p>\n<\/div>\n<p>The latitude at which the sun is directly overhead at noon is called the <strong>latitude of the subsolar point<\/strong>. The sun is directly overhead of the equator at noon on the equinoxes. It is directly overhead of the Tropic of Cancer at noon on the June solstice, and directly overhead of the Tropic of Capricorn at noon on the December solstice. In between these dates, you can determine the latitude of the subsolar point\u00a0using a diagram called the <strong>analemma\u00a0<\/strong>(<a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a>).<\/p>\n<p>Reading the analemma is a three-step process:<\/p>\n<p><strong>Step 1<\/strong>: On the figure-8 shape, find the date for which you want to know the latitude of the subsolar point.<\/p>\n<p><strong>Step 2<\/strong>: Read across to the vertical axis on the left side of the analemma and read the latitude. <strong>Note: latitudes only go up to a maximum 23.5\u00b0, the latitude of the Tropic of Cancer and Capricorn, as the sun is never directly overhead at higher latitudes.<\/strong><\/p>\n<p><strong>Step 3<\/strong>: The analemma is split into the northern hemisphere (upper half, above 0\u00b0) and southern hemisphere (lower half, below 0\u00b0). Determine whether the latitude of the subsolar point is in the northern hemisphere or the southern hemisphere.<a id=\"figure2.1\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_1797\" aria-describedby=\"caption-attachment-1797\" style=\"width: 744px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1797 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2.png\" alt=\"image description linked in caption\" width=\"744\" height=\"1022\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2.png 744w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2-218x300.png 218w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2-65x89.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2-225x309.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Figure-2.1-Latitude-of-Subsolar-Pointv2-350x481.png 350w\" sizes=\"auto, (max-width: 744px) 100vw, 744px\" \/><figcaption id=\"caption-attachment-1797\" class=\"wp-caption-text\"><strong>Figure 2.1.<\/strong> Analemma diagram. This diagram is used to determine the latitude of the subsolar point based on calendar date. <em>Source: Modified by A. Perkins and C. Welch, CC BY-NC-SA 4.0. Modified from US Coast and Geodetic Survey, Public Domain.<a class=\"internal\" href=\"#id2.1\">[Image description]<\/a><\/em><\/figcaption><\/figure>\n<h3 style=\"text-align: left;\">The March of the Seasons and the Angle of the Noon Sun<\/h3>\n<p>Across the range of latitudes, locations near the Equator receive high quantities of insolation all year long. Locations near the poles only receive significant amounts of insolation during a relatively short summer period. For this reason, localities near the poles have cold winter conditions during most of the year.<\/p>\n<div class=\"textbox\">\n<p style=\"text-align: center;\"><strong>Reading: <a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Heat-Imbalances-NASA.pdf\">Heating Imbalances [PDF]<\/a><\/strong><\/p>\n<p>This short article describes how Earth\u2019s tilt and surface reflectivity impact heating imbalances across Earth and drive atmospheric and oceanic circulation on Earth. The same information is available on <a href=\"https:\/\/earthobservatory.nasa.gov\/Features\/EnergyBalance\/page3.php\">the NASA Earth Observatory website.<\/a><\/p>\n<\/div>\n<p>The angle at which solar radiation encounters the Earth\u2019s surface is important for how that energy is distributed. The <strong>angle of the noon sun (ANS)<\/strong> is calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a>:<\/p>\n<p><a id=\"equation2.1\" class=\"internal\"><\/a><strong>\u00a0Equation 2.1<\/strong><\/p>\n<p>ANS = 90\u00b0 \u2212 (Latitude \u00b1 Latitude of the Subsolar Point)<\/p>\n<p>where<\/p>\n<ul>\n<li>ANS = the angle of the noon sun (expressed in degrees)<\/li>\n<li>Latitude = the desired location on the surface of the Earth<\/li>\n<li>Latitude of the subsolar point (LSP) = the latitude where the sun is directly overhead for that date of the year.<\/li>\n<\/ul>\n<p>Examples of how to calculate the difference between latitude for your location and the LSP are presented in <a class=\"internal\" href=\"#figure2.2\">Figure 2.2<\/a> for three scenarios. Important points to take note of:<\/p>\n<ul>\n<li>You are interested in the total difference in latitude between our location and the LSP.<\/li>\n<li>You cannot have a sun angle greater than 90\u00b0.<\/li>\n<li>When determining whether you should add or subtract the LSP <strong>within Equation 2.1 specifically<\/strong>, consider which hemisphere you are in, and whether it is the &#8220;summer half&#8221; of the year (location is tilted towards the sun) or the &#8220;winter half&#8221; of the year (location is tilted away from the sun). If you are in the &#8220;summer half&#8221; of the year (i.e., approximately March 23 &#8211; September 20 in the Northern Hemisphere), then you subtract the LSP in Equation 2.1. If you are in the &#8220;winter half&#8221; of the year (i.e., approximately March 23 &#8211; September 20 in the Southern Hemisphere), then you add the LSP in Equation 2.1.\u00a0<a id=\"figure2.2\" class=\"internal\"><\/a><\/li>\n<\/ul>\n<figure id=\"attachment_1798\" aria-describedby=\"caption-attachment-1798\" style=\"width: 600px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1798\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example.png\" alt=\"\" width=\"600\" height=\"244\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example.png 3747w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-300x122.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-1024x416.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-768x312.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-1536x624.png 1536w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-2048x832.png 2048w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-65x26.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-225x91.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.2-ANS_Example-350x142.png 350w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption id=\"caption-attachment-1798\" class=\"wp-caption-text\"><strong>Figure 2.2.<\/strong> Scenarios for calculating angle of the noon sun, based on varying positions of latitude and LSP. In Scenario 1, you are in the Northern Hemisphere and it is the &#8220;summer&#8221; half of the year so you subtract the LSP. In Scenario 2, you are in the Northern Hemisphere and it is the &#8220;winter&#8221; half of the year so you add the LSP. In Scenario 3, you are in the Northern Hemisphere and it is the &#8220;winter&#8221; half of the year so you subtract the LSP. Because Scenario 3 is within 23.5 degree of the equator, you have to account for this by either flipping the location and LSP (when calculating the difference), or adding (180 &#8211; ) to the start of <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a>. S<em>ource: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<p>Let us assume that we are located at 49\u00b0 N on July 14. From the analemma in <a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a> we determine that the LSP is 21.5\u00b0 N. ANS may therefore be calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a> as:<\/p>\n<p>[latex]\\begin{array}{ll}\\text{ANS}& = 90^{\\circ} - (\\text{Latitude}-\\text{Latitude of the Subsolar Point}) \\\\ &= 90^{\\circ} - (49^{\\circ} - 21.5^{\\circ}) = 62.5^{\\circ}\\end{array}[\/latex]<\/p>\n<p>When sunlight impacts the Earth\u2019s surface at an oblique angle, the insolation is stretched over a greater area, reducing its <strong>intensity <\/strong>(<a class=\"internal\" href=\"#figure2.3\">Figure 2.3<\/a>).<a id=\"figure2.3\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_40\" aria-describedby=\"caption-attachment-40\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-40\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle.png\" alt=\"When sunlight 1 metre wide hits the Earth at a 90 degree angle, it hits 1 m of ground. When sunlight 1 metre wide hits the Earth at a 45 degree angle, it hits 1.4 m of ground, which is a 40% increase in area covered by the same sunlight. This decreases the intensity of sunlight that hits each point on the Earth\u2019s surface.\" width=\"650\" height=\"369\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle.png 683w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle-300x170.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle-65x37.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle-225x128.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.3-Reduction-in-solar-intensity-as-sunlight-encounters-the-Earths-surface-at-an-oblique-angle-350x199.png 350w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><figcaption id=\"caption-attachment-40\" class=\"wp-caption-text\"><strong>Figure 2.3<\/strong>. Reduction in solar intensity as sunlight encounters the Earth\u2019s surface at an oblique angle. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<p>We can extend the ANS calculation to also look at the effect angle of incidence has on insolation intensity using <a class=\"internal\" href=\"#equation2.2\">Equation 2.2<\/a>:<\/p>\n<p><strong><a id=\"equation2.2\" class=\"internal\"><\/a>Equation 2.2<\/strong><\/p>\n<p>[latex]\\text{Intensity} = sin(\\text{ANS})[\/latex]<\/p>\n<p>This is a unitless value for intensity between 0 and 1, that can be multiplied by 100 to yield a percentage of the 100% intensity currently experienced at the latitude of the subsolar point.<\/p>\n<p>For example, at 49\u00b0 N on July 14, and using the ANS calculated using <a class=\"internal\" href=\"#equation2.1\">Equation 2.1<\/a> above, the solar intensity (<a class=\"internal\" href=\"#equation2.2\">Equation 2.2<\/a>) would be:<\/p>\n<p>[latex]\\text{Intensity} = sin(62.5^{\\circ}) = 0.89\\text{ or } 0.89\\times 100\\% = 89\\%[\/latex]<\/p>\n<div>\n<p><a class=\"internal\" href=\"#figure2.4\">Figure 2.4<\/a> presents a summary of incoming solar radiation for July 14 at 49\u00b0 N latitude. A line has been drawn on a protractor to demonstrate the incoming angle of solar radiation (ANS = 62.5\u00b0). This corresponds to a relative intensity of 0.89 or 89%.<a id=\"figure2.4\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_1799\" aria-describedby=\"caption-attachment-1799\" style=\"width: 600px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1799\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower.png\" alt=\"\" width=\"600\" height=\"185\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower.png 2229w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-300x92.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-1024x315.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-768x236.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-1536x473.png 1536w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-2048x630.png 2048w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-65x20.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-225x69.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.4-ANS_Diagram_EiffelTower-350x108.png 350w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption id=\"caption-attachment-1799\" class=\"wp-caption-text\"><strong>Figure 2.4.<\/strong> Incoming solar radiation on July 14 at 49\u00b0 latitude (Eiffel Tower). The angle of the noon sun (ANS) is depicted on the protractor (left) and expressed as a value in the box (right). Relative intensity of solar radiation is also shown on the right as a unitless value (0.89). This could also be expressed as 89%. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<h3 style=\"text-align: left;\">Earth&#8217;s Energy Budget<\/h3>\n<p>In order to maintain a stable climate over long periods of time, the energy inputs to Earth (insolation) must be balance by energy outputs, radiated as heat. This balance is also known as Earth&#8217;s energy budget. On average,<\/p>\n<ul>\n<li>23% of energy is absorbed in the atmosphere by gases, dust, and other particles,<\/li>\n<li>48% of energy is absorbed at the surface, and<\/li>\n<li>29% of energy is reflected directly back to space by clouds, particles, or bright ground surfaces such as ice (<a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page4.php\">NASA Earth Observatory (1), 2009<\/a>).<\/li>\n<\/ul>\n<p>As we can see from these percentages, the surface of Earth and the surrounding atmosphere play different roles in energy absorption and loss. Most energy is absorbed at the surface, while most energy is radiated back to space from the atmosphere.<\/p>\n<p>As noted above, approximately 48% of incoming solar radiation is absorbed at the surface. This energy is returned to the atmosphere through three processes:<\/p>\n<ol>\n<li>25% through <strong>evaporation<\/strong>, i.e., turning liquid water into water vapour,<\/li>\n<li>5% through <strong>convection<\/strong>, i.e., air warming in contact with the ground and rising, and<\/li>\n<li>net 17% as infrared thermal energy (heat) (<a href=\"https:\/\/earthobservatory.nasa.gov\/features\/EnergyBalance\/page5.php\"><span style=\"background-color: #ffffff;\">NASA Earth Observatory (2), 2009<\/span><\/a>).<\/li>\n<\/ol>\n<h2 style=\"text-align: left;\">Global Temperature Distribution and Common Temperature Scales<\/h2>\n<p>Based on what you now know about how the sun\u2019s energy is distributed around the globe, it should make sense that incoming solar radiation is unequally received at the Earth\u2019s surface. One of the easiest ways to see this is by examining average temperatures by latitude.<\/p>\n<p>The three maps at the links below show global surface temperatures at the two solstice positions and at the equinox. Surface temperatures are displayed as colour, with red indicating hotter temperatures and blues and purples indicating colder temperatures. You can view the complete temperature scale by clicking on the hamburger menu in the bottom-left corner of the screen. What do you notice about latitudinal changes in temperature as you move from the equator to the poles? You can click anywhere on the map to get a temperature reading for that location.<\/p>\n<p><a href=\"https:\/\/earth.nullschool.net\/#2020\/06\/21\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">June Solstice<\/a><\/p>\n<p><a href=\"https:\/\/earth.nullschool.net\/#2019\/12\/20\/0800Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">December Solstice<\/a><\/p>\n<p><a href=\"https:\/\/earth.nullschool.net\/#2020\/03\/20\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">Equinox<\/a><\/p>\n<p>Temperature is a measure of the average kinetic energy of a substance. It is a way of measuring heat energy, as heat always flows from material at a high temperature to material at a lower temperature, raising the temperature of the cooler material. There are three temperature scales that are commonly used: Celsius (\u00b0C), Fahrenheit (\u00b0F), and Kelvin (K). Most of the world (including most of the scientific world) uses the Celsius scale for measurement and reporting.<\/p>\n<p>The following formulas allow you to convert between these scales.<\/p>\n<p><strong><a id=\"equation2.3\" class=\"internal\"><\/a>Equation 2.3.<\/strong> Convert from Fahrenheit to Celsius:<\/p>\n<p>[latex]T{(^{\\circ} C)} = \\dfrac {5}{9} \\times \\left( T{(^{\\circ} F)} - 32 \\right)[\/latex]<\/p>\n<p><a id=\"equation2.4\" class=\"internal\"><\/a><strong>Equation 2.4.<\/strong> Convert from Celsius to Fahrenheit:<\/p>\n<p>[latex]T{(^{\\circ} F)} = \\left( \\dfrac {9}{5} \\times T{(^{\\circ} C)} \\right) + 32[\/latex]<\/p>\n<p><strong><a id=\"equation2.5\" class=\"internal\"><\/a>Equation 2.5.<\/strong> Convert from Kelvin to Celsius:<\/p>\n<\/div>\n<p>[latex]T{(^{\\circ} C)} = T(K) - 273[\/latex]<\/p>\n<p><a id=\"equation2.6\" class=\"internal\"><\/a><strong>Equation 2.6.<\/strong> Convert from Celsius to Kelvin:<\/p>\n<p>[latex]T(K) = T{(^{\\circ} C)} + 273[\/latex]<\/p>\n<p>where<\/p>\n<ul>\n<li style=\"text-align: left;\">T (\u00b0C) = Temperature in degrees Celsius<\/li>\n<li style=\"text-align: left;\">T (\u00b0F) = Temperature in degrees Fahrenheit<\/li>\n<li style=\"text-align: left;\">T (K) = Temperature in Kelvin<\/li>\n<\/ul>\n<h2 style=\"text-align: left;\">Temperature Gradients<\/h2>\n<p>A gradient is the rate of change for a value over a given distance. It can be useful for many environmental variables like imaging how topography changes over space or how temperature varies vertically or horizontally through the atmosphere.<\/p>\n<p>Temperature changes along a gradient through the atmosphere are called <strong>lapse rates<\/strong>.\u00a0Lapse rates can be calculated using <a class=\"internal\" href=\"#equation2.7\">Equation 2.7<\/a>:<\/p>\n<p><strong><a id=\"equation2.7\" class=\"internal\"><\/a>Equation 2.7<\/strong><\/p>\n<p>[latex]\\text{Lapse rate} (^{\\circ} C\/km) = -1 \\left( \\dfrac{\\Delta T}{\\Delta z} \\right) = -1 \\left( \\dfrac{T_{2} - T_{1}}{z_{2} - z_{1}} \\right)[\/latex]<\/p>\n<p>where<\/p>\n<ul>\n<li>\u0394 = delta symbol, represents the <strong>change<\/strong> in the variable it precedes (for example, the change in temperature)<\/li>\n<li>T = air temperature (normally in \u00b0C)<\/li>\n<li>z = altitude (normally in km). This term can be replaced with distance if calculating a horizontal temperature gradient<\/li>\n<li>T<sub>1<\/sub> , z<sub>1 <\/sub>= the measurement taken at the lower point in the atmosphere<\/li>\n<\/ul>\n<p>For example, let\u2019s say you wanted to know the lapse rate between the two temperature readings in the atmosphere shown on Figure 2.5.<a id=\"figure2.5\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_42\" aria-describedby=\"caption-attachment-42\" style=\"width: 500px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-42\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations.png\" alt=\"Scatter plot with altitude in Kilometres on the y-axis and temperature in Celsius on the x-axis. Measurement 1 was 10 degrees Celsius at 2 km altitude and measurement 2 was \u2013 30 degrees Celsius at 8 km altitude.\" width=\"500\" height=\"366\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations.png 644w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations-300x220.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations-65x48.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations-225x165.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.5-Lapse-Rate-Locations-350x257.png 350w\" sizes=\"auto, (max-width: 500px) 100vw, 500px\" \/><figcaption id=\"caption-attachment-42\" class=\"wp-caption-text\"><strong>Figure 2.5.<\/strong> Altitude (z) and temperature (T) of two measurement locations used to calculate lapse rate. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<p>We can read the required values from <a class=\"internal\" href=\"#figure2.5\">Figure 2.5<\/a>: T<sub>1<\/sub> is 10\u00b0C at z<sub>1<\/sub> of 2 km, and T<sub>2<\/sub> is \u221230\u00b0 at z<sub>2<\/sub> of 8 km. Hence, the lapse rate is calculated using <a class=\"internal\" href=\"#equation2.7\">Equation 2.7<\/a> as:<\/p>\n<p>[latex]\\begin{array}{ll}\\text{Lapse rate} (^{\\circ} C\/km)& = -1 \\left( \\dfrac{\\Delta T}{\\Delta z} \\right) = -1 \\left( \\dfrac{T_{2} - T_{1}}{z_{2} - z_{1}} \\right)\\\\&= -1 \\left( \\dfrac{-30^{\\circ} C - 10^{\\circ} C}{8km - 2km} \\right) = -1 \\left( \\dfrac{-40^{\\circ} C}{6km} \\right) = 6.6^{\\circ} C\/km\\end{array}[\/latex]<\/p>\n<p>Notice that the lapse rate above has a positive value. This means that based on the series in which the measurements were taken, the temperature is decreasing as the altitude increases, which is the normal condition in the troposphere.<\/p>\n<h2 style=\"text-align: left;\">Albedo and Aspect<\/h2>\n<p>Local variations in surface reflectivity, called <strong>albedo<\/strong>, and the direction a surface faces, its <strong>aspect<\/strong>, can have a major influence on that surface&#8217;s absorption and retention of solar radiation.<\/p>\n<p><strong>Albedo<\/strong> is measured as the percentage of radiation reflected from a surface (Figure 2.6). High albedo surfaces have a high reflectivity. Surfaces like ice are highly reflective and absorb very little incoming solar radiation. Surfaces like asphalt and concrete have a very low reflectivity and absorb significant amounts of incoming solar radiation (Figure 2.6). This difference in albedo leads to significant differences in heating. In the atmosphere, clouds have a very high albedo and reflect energy, whereas particulate matter has a low albedo and absorbs energy.<a id=\"figure2.6\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_1800\" aria-describedby=\"caption-attachment-1800\" style=\"width: 2524px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1800 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo.png\" alt=\"image description linked to in caption\" width=\"2524\" height=\"1596\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo.png 2524w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-300x190.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-1024x648.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-768x486.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-1536x971.png 1536w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-2048x1295.png 2048w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-65x41.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-225x142.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.6-Albedo-350x221.png 350w\" sizes=\"auto, (max-width: 2524px) 100vw, 2524px\" \/><figcaption id=\"caption-attachment-1800\" class=\"wp-caption-text\"><strong>Figure 2.6.<\/strong> Albedo of common surfaces.\u00a0<em>Source: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Albedo-e_hg.png\">H. Grobe (2000) <\/a>CC BY-SA 2.5. <\/em><strong>B:<\/strong> Pictorial demonstration of how albedo controls reflection and absorption of energy received from the sun. <em>Source:\u00a0<a href=\"https:\/\/journals.plos.org\/plosone\/article?id=10.1371\/journal.pone.0213368\">Prevedello et al (2019)<\/a>. CC BY.<\/em> <a class=\"internal\" href=\"#id2.6\">[Image description]<\/a><\/figcaption><\/figure>\n<p><strong>Aspect<\/strong> refers to the direction a topographic slope is facing (<a class=\"internal\" href=\"#figure2.7\">Figure 2.7<\/a>). We refer to direction based on the cardinal points of a compass. A southerly aspect means that the topographic slope is facing to the south. In the mid latitudes of the northern hemisphere, a southerly aspect means that a slope is tilted towards incoming solar radiation (based on angle of the noon sun). A northerly aspect in the same location would mean that the slope is tilted away from incoming solar radiation.<a id=\"figure2.7\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_1801\" aria-describedby=\"caption-attachment-1801\" style=\"width: 2713px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1801 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2.png\" alt=\"\" width=\"2713\" height=\"1127\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2.png 2713w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-300x125.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-1024x425.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-768x319.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-1536x638.png 1536w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-2048x851.png 2048w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-65x27.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-225x93.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Fig-2.7-Aspect2-350x145.png 350w\" sizes=\"auto, (max-width: 2713px) 100vw, 2713px\" \/><figcaption id=\"caption-attachment-1801\" class=\"wp-caption-text\"><strong>Figure 2.7. <\/strong>Cardinal directions on the compass. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em> <strong>B:<\/strong> An illustration of the concept of aspect in the northern hemisphere. The slope labelled with a yellow star has a north-facing aspect in the image, whereas the slope labelled with the pink square has a south-facing aspect. <em>Modified after <a href=\"https:\/\/tc.copernicus.org\/articles\/13\/29\/2019\/\">Olsen &amp; Rupper (2019)<\/a> CC BY.<\/em><\/figcaption><\/figure>\n<h1>Lab Exercises<\/h1>\n<p>In this lab you will explore how Earth-Sun relationships generate latitudinal and seasonal differences in temperature, and the foundations for Earth\u2019s radiation budget. You will use several online maps and interactive websites to complete this exercise.<\/p>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EX1: Earth-Sun Relationships and Earth&#8217;s Energy Budget<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ol>\n<li>According to the NASA article you read (<a style=\"text-align: initial; font-size: 1em;\" href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2020\/05\/Incoming-sunlight-NASA.pdf\" rel=\"noopener\">Incoming Sunlight [PDF]<\/a>), day and night, averaged around the globe, how much energy reaches the Earth from the sun?<\/li>\n<li>The above number describes an <strong>average <\/strong>value across the Earth. Describe the three factors that determine the <strong>actual <\/strong>amount of radiation received at the Earth\u2019s surface at a specific location.<\/li>\n<\/ol>\n<p>The solar constant measures the approximate solar radiation received at the top of the atmosphere. However, at various times throughout the year, certain latitudes tilt towards or away from the sun, based on Earth\u2019s orbit. For example, in December, the northern hemisphere is tilted away from the sun, whereas in July, the southern hemisphere is tilted away from the sun.<\/p>\n<p>Open <a href=\"https:\/\/cimss.ssec.wisc.edu\/wxfest\/SunAngle\/sunangle.html\">Explore the Effect of the Angle of Incidence on the Sun&#8217;s Energy Interactive Diagram<\/a> to answer questions 3 and 4. <strong>Note this interactive is simplified to only communicate changes in radiation based on sun angle and does not include the influence of the atmosphere on incoming solar radiation.<\/strong><\/p>\n<ol start=\"3\">\n<li>Set the month in the box at the bottom of the interactive to \u201cMarch.\u201d Explain how the amount of solar radiation received at Earth\u2019s surface changes as you move from the equator to the north pole.<\/li>\n<li>Now let&#8217;s see how this changes throughout the year. To get the values you need, cycle through the four months in the box at the bottom of the interactive.\n<ol type=\"a\">\n<li>Record the actual amount of radiation received at Earth\u2019s surface for three latitudes: Equator, Tropic of Cancer and the North Pole in <a class=\"internal\" href=\"#table2.1\">Table 2.1<\/a>. This table is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.<br \/>\n<table class=\"grid aligncenter\" style=\"border-collapse: collapse; width: 50%;\">\n<caption><a id=\"table2.1\" class=\"internal\"><\/a>Table 2.1. Actual amount of radiation received at Earth&#8217;s surface on the equinoxes and solstices at three locations.<\/caption>\n<tbody>\n<tr>\n<th scope=\"col\">Month<\/th>\n<th scope=\"col\">Equator<\/th>\n<th scope=\"col\">Tropic of Cancer<\/th>\n<th scope=\"col\">North Pole<\/th>\n<\/tr>\n<tr>\n<td style=\"width: 20%;\">March<\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%;\">June<\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%;\">September<\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<\/tr>\n<tr>\n<td style=\"width: 20%;\">December<\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<td style=\"width: 20%;\"><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n<li>Graph the points for each month on <a class=\"internal\" href=\"#figure2.8\">Figure 2.8<\/a>, connecting each with lines. Use different symbols for each line and include a legend to reference the symbols. This graph is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.<a id=\"figure2.8\" class=\"internal\"><\/a><br \/>\n<figure id=\"attachment_45\" aria-describedby=\"caption-attachment-45\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-45\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8.png\" alt=\"\" width=\"650\" height=\"460\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8.png 1718w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-300x212.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-1024x725.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-768x544.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-1536x1087.png 1536w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-65x46.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-225x159.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.8-350x248.png 350w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><figcaption id=\"caption-attachment-45\" class=\"wp-caption-text\"><strong>Figure 2.8.<\/strong> Change in energy received at Earth&#8217;s surface through time. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<p>Use the analemma (<a class=\"internal\" href=\"#figure2.1\">Figure 2.1<\/a>) to answer questions 5 and 6:<\/p>\n<ol start=\"5\">\n<li>At what latitude is the Sun directly overhead on your birthday? Record the date and the latitude of the subsolar point.<\/li>\n<li>Earth Day is celebrated on April 22nd every year. At what latitude is the sun directly overhead on this date?<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EX2: The March of the Seasons and the Angle of the Noon Sun<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>The latitude at which the Sun is directly overhead may be helpful in understanding overall Sun patterns, but let&#8217;s say you want to set up a solar panel at your house. You need to know the sun angle for your location on a specific date so that you can setup your solar panel for optimal effectiveness.<\/p>\n<ol start=\"7\">\n<li>Complete the following calculations for angle of the noon sun (ANS) and relative solar intensity (Intensity, expressed as a percentage). Draw the angle on the figures provided. Show your working. These figures are also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.\n<ol type=\"a\">\n<li>On Oct. 3rd, if you are located at 0\u00b0 latitude.<br \/>\n<table class=\"grid aligncenter\">\n<tbody>\n<tr>\n<td rowspan=\"2\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png 298w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-65x43.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-225x147.png 225w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><br \/>\n<\/strong><\/td>\n<th scope=\"col\">Angle of Noon Sun<\/th>\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n<li>On April 2nd, if you are located at 61\u00b0 North latitude.<br \/>\n<table class=\"grid aligncenter\">\n<tbody>\n<tr>\n<td rowspan=\"2\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png 298w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-65x43.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-225x147.png 225w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><br \/>\n<\/strong><\/td>\n<th scope=\"col\">Angle of Noon Sun<\/th>\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n<li>On Dec. 9th, if you are located at 85\u00b0 North latitude.<br \/>\n<table class=\"grid aligncenter\">\n<tbody>\n<tr>\n<td rowspan=\"2\"><strong><img loading=\"lazy\" decoding=\"async\" class=\"alignleft wp-image-46 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png\" alt=\"Person standing on ground. Left of image is north, right of image is south.\" width=\"298\" height=\"195\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image.png 298w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-65x43.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Lab-2-Example-Image-225x147.png 225w\" sizes=\"auto, (max-width: 298px) 100vw, 298px\" \/><br \/>\n<\/strong><\/td>\n<th scope=\"col\">Angle of Noon Sun<\/th>\n<th scope=\"col\">Relative Intensity of the Sun Angle<\/th>\n<\/tr>\n<tr>\n<td><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n<\/ol>\n<\/li>\n<li>It&#8217;s August 1st and you are climbing up the south facing slope of Mount Denali in Alaska (the highest peak in North America). At noon you come across another climber in distress and need to contact emergency services for a helicopter rescue, but your satellite phone battery is dead. Quickly you remember that you have a portable solar panel charger in your backpack. You unpack it and plug it in to the phone. It begins to charge, but very slowly. You decide to speed up the charge by setting up the solar panel at an angle.<\/li>\n<\/ol>\n<p style=\"padding-left: 40px;\">At what angle should you set the solar panel to take the best advantage of the incoming solar radiation? <strong>Show all relevant calculations.<\/strong> <a class=\"internal\" href=\"#figure2.9\">Figure 2.9<\/a> is also provided in <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a> at the bottom of this lab.<a id=\"figure2.9\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_47\" aria-describedby=\"caption-attachment-47\" style=\"width: 442px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-47\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle.png\" alt=\"Solar panel raised above ground at unknown angle.\" width=\"442\" height=\"355\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle.png 602w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle-300x241.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle-65x52.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle-225x181.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.9-Solar-panel-angle-350x281.png 350w\" sizes=\"auto, (max-width: 442px) 100vw, 442px\" \/><figcaption id=\"caption-attachment-47\" class=\"wp-caption-text\"><strong>Figure 2.9.<\/strong> Schematic of solar panel. <em>Source: A. Perkins, CC BY-NC-SA 4.0.<\/em><\/figcaption><\/figure>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EX3: Global Temperature Distribution and Common Temperature Scales<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>Seasonality and Sun angle is just one way incoming solar radiation can vary for a specific location. Using satellite measurements it is possible to get a sense of how cloud cover affects incoming solar radiation.<\/p>\n<p>This <a href=\"https:\/\/www.ssec.wisc.edu\/~tomw\/ams\/amsimage.html\">Satellite Temperature Data website<\/a> displays temperature data collected by a satellite looking through the atmosphere from above. It calculates the temperature from the reflective surface in the image.<\/p>\n<ol start=\"9\">\n<li>Choose a location on the map where you can see a cloudless area near the coast. Compare the land and ocean temperatures at this latitude. Is there a difference between the temperatures? Explain why this is the case.<\/li>\n<li>Now compare the temperatures in the previous question with the temperature measurement at the top of a nearby cloud.\n<ol type=\"a\">\n<li>Is the temperature at the top of the cloud higher or lower than the land and water surfaces?<\/li>\n<li>What does this tell you about how energy radiated from the Earth\u2019s surface is affected as it interacts with clouds in the atmosphere on its way out to space?<\/li>\n<li>Assume the top of the cloud is at the top of the troposphere, 18 km above the land surface for your location. Calculate the lapse rate between the Earth\u2019s land surface and the top of the cloud. Show your work.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<hr \/>\n<p>On April 10, 1912 the steamship Titanic left Southampton England on its maiden voyage across the Atlantic Ocean to New York (<a class=\"internal\" href=\"#figure2.10\">Figure 2.10<\/a>). By the evening of April 15, the Titanic was sinking in the middle of the Atlantic Ocean, after striking an iceberg. The Titanic sank in the cold waters of the northern Atlantic.<a id=\"figure2.10\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_754\" aria-describedby=\"caption-attachment-754\" style=\"width: 2560px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-754 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabs2020\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.10-Titanic-in-Cork-Harbour-scaled-1.jpg\" alt=\"\" width=\"2560\" height=\"1149\" \/><figcaption id=\"caption-attachment-754\" class=\"wp-caption-text\"><strong>Figure 2.10.<\/strong> Titanic on its maiden voyage, off the coast of Ireland (Photo taken on April 11, 1912). <em>Source: <a href=\"https:\/\/commons.wikimedia.org\/wiki\/File:Titanic-Cobh-Harbour-1912.JPG\">Cobh Heritage Centre, Public Domain<\/a>.<\/em><\/figcaption><\/figure>\n<ol start=\"11\">\n<li>The surface temperature when the Titanic left Southampton, England was 53.1 \u00b0F. Convert this temperature to \u00b0C.<\/li>\n<li>The average daily maximum temperature for Southampton, England in April 1912 was 288.5 K. Was the temperature when the Titanic left higher or lower than this average?<\/li>\n<li>The city of Calgary, Alberta is located at a similar latitude to the city of Southampton, England. In April 1912, the average daily maximum temperature in Calgary was 5.5 \u00b0C. Explain the physical geography surrounding why this temperature is so different than the average daily maximum temperature in Southampton. Hint: you may need to look at a map of where Calgary is located relative to where Southampton is.<\/li>\n<\/ol>\n<p>The Titanic sailed in April, between the extreme conditions of summer and winter. Consult the global temperature maps below for an example of January and July temperatures:<\/p>\n<ul>\n<li style=\"text-align: left;\"><a href=\"https:\/\/earth.nullschool.net\/#2019\/07\/15\/0700Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">July Temperatures<\/a><\/li>\n<li style=\"text-align: left;\"><a href=\"https:\/\/earth.nullschool.net\/#2020\/01\/01\/0800Z\/wind\/isobaric\/1000hPa\/overlay=temp\/winkel3\">January Temperatures<\/a><\/li>\n<\/ul>\n<p>Recall that the maps show temperature displayed as colour: reds indicate hotter temperatures and blues to purples indicate colder temperatures. So, all locations with the same colour will have similar temperatures. You can click anywhere on the map to get a temperature reading for that location.<\/p>\n<ol start=\"14\">\n<li>Is the temperature contrast between the equator and the Arctic region greatest in winter or summer for the northern hemisphere?<\/li>\n<li>If latitude were the only control on temperature, the colour bands indicating similar temperatures should run straight across the map from east to west.\n<ol type=\"a\">\n<li>Identify one area on the map where this occurs. Use your knowledge of place names or use an atlas or <a href=\"https:\/\/www.google.com\/earth\/index.html\">Google Earth<\/a> to determine the name of the location you identified.<\/li>\n<li>What physical geography conditions explain why the temperatures follow this pattern in the place you identified?<\/li>\n<\/ol>\n<\/li>\n<li>Compare the January and July maps temperature maps.\n<ol type=\"a\">\n<li>Describe one area of the world that exhibits a large annual temperature range.<\/li>\n<li>What physical geography conditions explain the large annual temperature range for the place you identified?<\/li>\n<\/ol>\n<\/li>\n<li>The atmospheric conditions on the night of April 15, 1912 were clear, that is, there was no cloud cover. How do you think the lack of clouds that night affected the air temperature, according to what we know about local energy budget and how clouds interact with radiation?<\/li>\n<li>The last emergency communication from the Titanic before it sank gave its position at the following coordinates: 41\u02da 46\u2019 N, 50\u02da 14\u2019 W. Go back to the <a href=\"https:\/\/www.ssec.wisc.edu\/~tomw\/ams\/amsimage.html\">Satellite Temperature Data website<\/a>. Find some open water in the Atlantic Ocean at a latitude of around 41\u00b0N.\n<ol type=\"a\">\n<li>Record the surface water temperature in \u00b0C.<\/li>\n<li>Survival rates for humans in specific water temperatures are given in <a class=\"internal\" href=\"#table2.2\">Table 2.2<\/a>. Based on the water temperature you obtained in part a, how long would an individual have been able to survive in open water after abandoning the Titanic?<br \/>\n<table class=\"grid aligncenter\" style=\"width: 40%;\">\n<caption><a id=\"table2.2\" class=\"internal\"><\/a>Table 2.2. Expected time of survival for humans in specific water temperatures.<\/caption>\n<tbody>\n<tr>\n<th scope=\"col\">Water Temperature (\u00b0F)<\/th>\n<th scope=\"col\">Expected Time of Survival<\/th>\n<\/tr>\n<tr>\n<td>32.5\u00b0<\/td>\n<td>45 minutes<\/td>\n<\/tr>\n<tr>\n<td>32.5\u201340\u00b0<\/td>\n<td>30 \u2013 90 minutes<\/td>\n<\/tr>\n<tr>\n<td>40\u201350\u00b0<\/td>\n<td>1 \u2013 3 hours<\/td>\n<\/tr>\n<tr>\n<td>50\u201360\u00b0<\/td>\n<td>1 \u2013 6 hours<\/td>\n<\/tr>\n<tr>\n<td>60\u201370\u00b0<\/td>\n<td>2 \u2013 40 hours<\/td>\n<\/tr>\n<tr>\n<td>70\u201380\u00b0<\/td>\n<td>3 hours \u2013 indefinite<\/td>\n<\/tr>\n<tr>\n<td>&gt; 80\u00b0<\/td>\n<td>Indefinite<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EX4: Lapse Rates<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>Several distress rockets were fired into the air to alert nearby ships of the Titanic\u2019s position and to aid in the rescue effort. Standard temperature values for different layers of the atmosphere are presented in <a class=\"internal\" href=\"#table2.3\">Table 2.3<\/a>.<\/p>\n<table class=\"grid aligncenter\" style=\"height: 96px; width: 75%;\">\n<caption><a id=\"table2.3\" class=\"internal\"><\/a>Table 2.3. Standard atmospheric temperature at specific points in the atmosphere.<\/caption>\n<tbody>\n<tr style=\"height: 16px;\">\n<th scope=\"col\">Atmospheric layer<\/th>\n<th scope=\"col\">Altitude (km)<\/th>\n<th scope=\"col\">Temperature (\u00b0C)<\/th>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"height: 16px; width: 221.883px;\">Surface (Northern hemisphere)<\/td>\n<td style=\"height: 16px; width: 104.45px;\">Sea level (0)<\/td>\n<td style=\"height: 16px; width: 136.567px;\">15<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"height: 16px; width: 221.883px;\">Tropopause<\/td>\n<td style=\"height: 16px; width: 104.45px;\">18<\/td>\n<td style=\"height: 16px; width: 136.567px;\">-57<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"height: 16px; width: 221.883px;\">Stratopause<\/td>\n<td style=\"height: 16px; width: 104.45px;\">50<\/td>\n<td style=\"height: 16px; width: 136.567px;\">0<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"height: 16px; width: 221.883px;\">Mesopause<\/td>\n<td style=\"height: 16px; width: 104.45px;\">80<\/td>\n<td style=\"height: 16px; width: 136.567px;\">-90<\/td>\n<\/tr>\n<tr style=\"height: 16px;\">\n<td style=\"height: 16px; width: 221.883px;\">Thermopause<\/td>\n<td style=\"height: 16px; width: 104.45px;\">480<\/td>\n<td style=\"height: 16px; width: 136.567px;\">1200<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<ol start=\"19\">\n<li>Plot the standard atmospheric temperature values presented in <a class=\"internal\" href=\"#table2.3\">Table 2.3<\/a> on the Exercise 4: Temperature Gradients Graph (provided in the <a class=\"internal\" href=\"#lab2worksheets\">Worksheets<\/a>). Connect the points with a line and label the troposphere, stratosphere, mesophere and thermosphere.<\/li>\n<li>The distress rockets passed through the lowest part of the atmosphere. Calculate the lapse rate in the lowest 10 km of the troposphere from the graph you created.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">EX5: Albedo and Aspect<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>Take a look at the glaciers that cover Mount Rainier, a stratovolcano in Washington, USA in <a class=\"internal\" href=\"#figure2.11\">Figure 2.11<\/a>, and use it to answer the questions that follow.<a id=\"figure2.11\" class=\"internal\"><\/a><\/p>\n<figure id=\"attachment_49\" aria-describedby=\"caption-attachment-49\" style=\"width: 1376px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-49 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier.png\" alt=\"aerial perspective of Mount Rainier and its glaciers. The glaciers radiate from the centre of the mountain peak in all directions. Glaciers on some sides appear larger and longer than others. The glaciers are separated by rocky terrain.\" width=\"1376\" height=\"1348\" srcset=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier.png 1376w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-300x294.png 300w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-1024x1003.png 1024w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-768x752.png 768w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-65x64.png 65w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-225x220.png 225w, https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/03\/Figure-2.11-Glaciers-of-Mount-Rainier-350x343.png 350w\" sizes=\"auto, (max-width: 1376px) 100vw, 1376px\" \/><figcaption id=\"caption-attachment-49\" class=\"wp-caption-text\"><strong>Figure 2.11.<\/strong> Mount Rainier, WA glacier coverage. The yellow star in the map inset shows where Mount Rainier is located in North America. <em>Source: <a href=\"https:\/\/www.usgs.gov\/media\/images\/glaciers-mount-rainier-overlaid-a-base-map-lidar-image-which\">Tom Sisson, USGS, Public Domain<\/a>.<\/em><\/figcaption><\/figure>\n<ol start=\"21\">\n<li>Mount Rainier contains the greatest amount of glacier ice of any mountain in the lower 48 United States.\n<ol type=\"a\">\n<li>Do you think aspect has a role in controlling the distribution and size of glaciers around the central peak of Mount Rainier? Explain your answer.<\/li>\n<li>Choose three different glaciers from different locations around the main peak. Compare their aspect and relative size.<\/li>\n<\/ol>\n<\/li>\n<li>The zones in between the glaciers are covered mostly in bare rock and light forested vegetation.\n<ol type=\"a\">\n<li>How do you think the albedo differences between the middle of the glacier and the locations between the glaciers affects how the glacier melts?<\/li>\n<li>As the glacier melts further back, more sediment and bare rock is revealed. Do you think this negatively or positively reinforces the melt rate of the glacier? Explain your answer.<\/li>\n<\/ol>\n<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--key-takeaways\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Reflection Questions<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<ol>\n<li>Imagine if Earth was not tilted 23.5\u00b0 on its axis, but instead had no tilt. How would this affect Earth\u2019s energy budget?<\/li>\n<li>If the Titanic had sunk on a cloudy night, how would that have affected air temperature conditions and potential survivability for those who had to abandon the ship as it sunk?<\/li>\n<li>The southern hemisphere is about 81% water at the surface, whereas the northern hemisphere is about 61% water how do you think this difference affects the local energy budget for these two different hemispheres?<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<h1><a id=\"lab2worksheets\" class=\"internal\"><\/a>Worksheets<\/h1>\n<p><a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.docx\">Lab 02 Student Workbook [Word]<\/a><\/p>\n<p><a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.odt\">Lab 02 Student Workbook [ODT]<\/a><\/p>\n<p><a href=\"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-content\/uploads\/sites\/1340\/2021\/08\/Lab-2-Student-Workbook.pdf\">Lab 02 Student Workbook [PDF]<\/a><\/p>\n<h1>References<\/h1>\n<p class=\"hanging-indent\">Prevedello, J.A., Winck, G.R., Weber, M.M., Nichols, E., &amp; Sinervo, B. (2019) Impacts of forestation and deforestation on local temperature across the globe. <em>PLoS ONE, 14<\/em>(3). https:\/\/doi.org\/10.1371\/journal.pone.0213368<\/p>\n<p class=\"hanging-indent\">Olson, M. &amp; Rupper, S. (2019) Impacts of topographic shading on direct solar radiation for valley glaciers in complex topography, <em>The Cryosphere<\/em>, 13, 29\u201340. https:\/\/doi.org\/10.5194\/tc-13-29-2019.<\/p>\n<h3>Image Descriptions<\/h3>\n<p><strong><a id=\"id2.1\" class=\"internal\"><\/a>Figure 2.1. Analemma diagram<\/strong><\/p>\n<p>The diagram shows an Analemma, a graph that demonstrates the latitude where the sun is directly overhead for different days of the year. For example, on the equinox dates it is directly overhead at the equator. The shape of the graph is in a figure-eight. The dates are shown on the figure-eight portion of the diagram and the latitudes are written on the y-axis.<\/p>\n<p><a class=\"internal\" href=\"#figure2.1\">[Return to Figure 2.1]<\/a><\/p>\n<p><strong><a id=\"id2.6\" class=\"internal\"><\/a>Figure 2.6. Albedo of common surfaces.<\/strong><\/p>\n<p>In part A) of the figure there is a table that shows different materials and their associated albedo measured as percent reflectivity. Water is at the bottom of the scale, with a low albedo and percentage of reflectivity and snow and ice are on the high end of the scale with a high albedo and percentage reflectivity. In part B) there is an image of two different land surfaces, the left side showing a highly vegetated surface that absorbs significant solar energy with low reflection, and the right side showing a bare land surface with significant reflection and high albedo.<\/p>\n<p><a class=\"internal\" href=\"#figure2.6\">[Return to Figure 2.6]<\/a><\/p>\n","protected":false},"author":970,"menu_order":3,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":["andrew-perkins"],"pb_section_license":""},"chapter-type":[],"contributor":[69],"license":[],"class_list":["post-52","chapter","type-chapter","status-publish","hentry","contributor-andrew-perkins"],"part":23,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapters\/52","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/wp\/v2\/users\/970"}],"version-history":[{"count":29,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapters\/52\/revisions"}],"predecessor-version":[{"id":2457,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapters\/52\/revisions\/2457"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/parts\/23"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapters\/52\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/wp\/v2\/media?parent=52"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/pressbooks\/v2\/chapter-type?post=52"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/wp\/v2\/contributor?post=52"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/geoglabmanualv2\/wp-json\/wp\/v2\/license?post=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}