Lab 2 (1)

University of Guelph Department of Geography GEOG*1300 - Introduction to the Biophysical Environment Fall 2023 LABORATORY EXERCISE 2 – ENERGY AT THE EARTH’S SURFACE In this lab you will develop some basic analog (i.e. Old School) skills working with an analemma and calculating energy budgets. You will need access to the internets to complete parts of the lab, but no special software. This lab is graded out of 25, but will be scaled to be worth the same as your other labs. Due Date: Before your next regularly assigned lab session (i.e. not during Thanksgiving week). Late submissions will be penalized at a rate of 10 percent of the value of the assignment per day. All assignments must be submitted through CourseLink. Extensions may be available with appropriate advance request. As always, I encourage you to work collectively to solve technical challenges, to discuss ideas, and to edit prose – but ultimately the work you submit (including graphs, math, and wording) must be your own work. It’s OK to show someone how to make a graph – it’s not OK to email them yours to include in their lab. Procedures. All answers can be completed on the worksheet that follows these instructions. I encourage you to save your final submission as a PDF to make sure that the formatting looks like what you think it will look like! Here are some tools that will be helpful: Equation for calculating noon sun angle: Sun Angle = 90 - (Latitude of Observation +/- SolarDeclination) ADD if latitude of observation and declination are in different hemispheres SUBTRACT if latitude of observation and declination are in the same hemisphere Hint: If you get a solar angle above 90 degrees you’ve made a mistake! 1

The Analema – Use this to find solar declination. 2

University of Guelph Department of Geography GEOG*1300 - Introduction to the Biophysical Environment Fall 2023 LABORATORY EXERCISE 2 – ENERGY AT THE EARTH’S SURFACE Name: Leanne Copp Student Number: 1245042 Lab Section: 0101 TA Name: Bowen PART A - Sun Angle, Length of Day, and Seasons 1. Calculate the noon sun angle for Seattle, WA, USA (47.6  N) on the following dates (show your calculations) (3 Marks) (a) June 21: SUN ANGLE= 90 – (latitude of observation +/- Solar declination) Sun angle = 90  - (47.6  + 23  ) =19.4  (b) October 15: SUN ANGLE= 90 – (latitude of observation +/- Solar declination) Sun angle = 90  - (47.6  -8  ) =50.4  (c) September 23: SUN ANGLE= 90 – (latitude of observation +/- Solar declination) Sun angle = 90  -(47.6  -0.5  ) =42.9  4

2 . What is the latitude in the northern hemisphere of a place where the noon sun angle is about 35  on about November 10? (show your work) (2 Marks) The latitude in the northern hemisphere where the noon sun angle is 35  on November 10 th is approximately 45.63  . 3. Determine the length of the day, and the directions for sunrise and sunset for the two locations in Table 1 using the time and date website (https://www.timeanddate.com/sun ). Enter the location’s name and select the correct date. Click on the day for a few extra details. (I’ve filled in Guelph for you; hopefully correctly). (2 Marks) Table 1. Day Length and Latitude for Selected Study Sites Name Generalized Latitude Feb. 14/23 Daylength (hours:min) Rise Bearing Set Bearing June 20/23 Daylength (hours:min) Rise Bearing Set Bearing Oct. 20/23 Daylength (hours:min) Rise Bearing Set Bearing Dec. 20/23 Daylength (hours:min) Rise Bearing Set Bearing Guelph, ON Canada 43°N 12:12 101° ESE 253° WSW 15:25 56 °NE 304° NW 10:49 104° ESE 256 WSW° 8:57 121° ESE 238° WSW Longyearbyen, Svalbard, Norway 78°N 00:00 Down all day 24:00 Up all day 4:54 144ºSE 216ºSW 00:00 Down all day Quito, Ecuador 0° 12:07 103º ESE 257ºWSW 12:07 67ºENE 293ºWNW 12:07 100ºB 259ºW 12:08 113ºESE 247ºWSW 4. Compare and contrast how day length changes for these locations. How is this related to seasonality? (2 Marks) Because of the earth's tilt and orbit, the length of the day varies for the places mentioned above. Seasonality is greatly influenced by the summer and winter solstices as well as the spring and fall equinoxes. The summer hemisphere is tilted toward the sun during the summer and winter in the northern hemisphere. 5

The time shortly before sunrise when there is enough light for humans to see is known as civil sunrise. When the sun first appears over the horizon is called sunrise. 8. How and why does that time difference vary between the three locations in Table 2? (2 Marks) The time difference varies between the three locations of Canada, Singapore, and Iceland because all three are located apart from each other in different time zones and distance latitudes but are still recorded on the same day. The earth’s rotation also has an effect on this. While the sun is rising in Iceland at 7:26 am, the sun is 4 hours ahead there than in Guelph Canada, so Guelph's time would be 3:26 am. PART B – The Energy Budget Use the information in Tables 3 and 4 to answer the questions in this section. Table 1. Weather station Solar data and albedo values for three 24 hour scenarios.   S 1 S 2 S 3 Q (direct Shortwave) W/m2 147 118 0 q (diffuse Shortwave) W/m2 63 67 0 α 0.15 0.60 0.80 L↓ (incoming longwave) W/m2 243 379 97 L↑ (outgoing longwave) W/m2 291 408 121 Table 2. Average albedo values for various surfaces Surface Average albedo (%) Water (sun angle >40  ) 3 Water (sun angle <40  ) 60 Fresh snow 80 Old snow 50 Ice 85 Dry sand 40 Dry concrete 25 Asphalt 7 Grass 15 Deciduous forest 15 Coniferous forest 10 7

Agricultural crops 20 9. Show your work and calculate the net radiation for each of the three scenarios. (3 Marks) #1: Rn = [(Q + q) – ((Q + q) × α)] + (L  - L  ) =[(147+63)-((147+63)x0.15)]+(243-291) =[210-(210x.15)]+(-48) =[210-31.5]+(-48) =178.5+(-48) =130.5 W/m2 #2: Rn = [(Q + q) – ((Q + q) × α)] + (L  - L  ) =[(118+67)-((118+67)x0.60)]+(379-408) =[185-(185x0.60)]+(-29) =[185-111]+(-29) =74+(-29) =45 W/m2 #3: Rn = [(Q + q) – ((Q + q) × α)] + (L  - L  ) =[(0+0)-((0+0)x0.80)]+(97-121) =[0x0.80]+(-24) =0+(-24) = -24 W/m2 10. Which scenario has the greatest amount of energy available to do work (report the value) ? What work can the energy from net radiation be utilized to do? (2 Marks) Out of all the scenarios, the first one has the most amount of net radiation. This also leads the first scenario to have the strongest amount of energy that we can work with. A few examples of what the energy can be utilized to do are Power ocean currents, warm the surface of the earth, and lastly drive the weather systems. 11. What is the primary cause for the changes in albedo? Use Table 4 and identify the types of surface likely associated with each Scenario? (2 Marks) 8