Lab # 2: Radiation Budgets Purpose: To explore the nature of the short and long-wave radiation balances interfacing between the earth's surface, its atmosphere and space for the present day climate (PDC) and for a glacial climate (GC). •This will allow you to: • Understand the difference between present day low latitudes and present day high latitudes climates as the temperature of the air at high latitudes is much cooler than lower latitudes
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Lab # 2: Radiation BudgetsPurpose: To explore the nature of the short and long-wave radiation balances interfacing between the earth's surface, its atmosphere and space for the present day climate (PDC) and for a glacial climate (GC).
•This will allow you to:
• Understand the difference between present day low latitudes and present day high latitudes climates as the temperature of the air at high latitudes is much cooler than lower latitudes
How does the radiation budget of a location like this one….
…differ from this one?
During Lab (week of Jan. 24th)1. Your TA will provide you during lab with the values
corresponding to each radiation fluxes (defined in Table 1) showing on the flow charts for PDC and GC.
Solar Radiation PDC GCKEX Extraterrestrial solar radiation (a) (ai)Cr Cloud reflection to space (b) (bi)Kf1 Cloud reflection downward (c) (ci)Ar Atmospheric reflection to space (d) (di)Kf2 Atmospheric reflection downward (e) (ei)Sr Earth surface reflection to space (f) (fi)Aa Atmospheric Absorption (g) (gi)Kd Diffused (h) (hi)
Long-wave RadiationLa Longwave radiation from surface absorbed (i) (ii)I n the atmosphereLs Longwave from surface to space through (j) (ji)
atmospheric windowLas Longwave from atmosphere to space (k) (ki)Las Longwave from atmosphere to surface (l) (li)
Surface Heat FluxesQE Latent heat of evapotranspiration (m) (mi)QH Sensible heat flux from surface to atmosphere (n) (ni)
During Lab (week of Jan. 24th)
2. Fill the flow charts with the values given for the radiation fluxes, for the PDC and the GC
3. Highlight in color the category of radiation to which a given radiation flux belongs to:• Solar (shortwave) radiation (e.g. in yellow)• Longwave radiation (emitted by Earth or the
atmosphere; e.g. in red)• Surface Heat fluxes (e.g. in blue)
• Don’t forget to include a legend that indicates what color is used for each category of radiation
• Remember! Refer to Table 1 to determine to which category a radiation flux belongs to
• Suggestion: Do this prior to showing up to lab• You don’t need the values to determine to which
category an arrow (i.e a radiation) belongs to!• It will take 10 minutes and save you lots of time
During the Lab (ct’d)4. Using the values in the flow charts for PDC and GC,
you must also calculate the radiation balance at each level using Table 2:• Top of Earth’s atmosphere (Balance to Space)• Surface of Earth (Surface Balance)• Within Earth’s atmosphere (Atmospheric Balance)
Balance to Space Surface Balance Atmospheric BalanceS PDC GC S PDC GC S PDC GC
In Out In Out In Out In Out In Out In Out
Total
How to use Table 2• For each balance that you must calculate, you will need to identify which fluxes you think are relevant for the balance you are considering
• You enter these in the column “S”
• You then enter the value for this radiation flux in the appropriate column, “In” ”-coming or “Out” ”-going radiation
• e.g. KEX is the shortwave solar radiation reaching the top of Earth’s atmosphere and has a value of 100• It is therefore entered under “Balance to Space”, and as “Out”
Balance to Space Surface Balance Atmospheric Balance
S PDC GC S PDC GC S PDC GC
In Out In Out In Out In Out In Out In Out
KEX 100 100
Total 100 100
• Since there is no other solar radiation that is incoming, the value of KEX constitutes the total of Out, for both the PDC and the GC
Balance to Space Surface Balance Atmospheric Balance
S PDC GC S PDC GC S PDC GC
In Out In Out In Out In Out In Out In Out
KEX 100 100
D 30 20
E 20 30
F 25 25
G 25 25
Total 100 100 100 100
• Then enter all the radiation fluxes that are leaving Earth to space under “In”. You will determine which ones counterbalance KEX. Their sum should equal total “Out”.
• NB: the values above are just an example
Balance to Space Surface Balance Atmospheric Balance
S PDC GC S PDC GC S PDC GC
In Out In Out In Out In Out In Out In Out
KEX 100 100 J 55 36 D 30 25
D 30 20 L 12 20 R 60 40
E 20 30 M 59 40 S 15 15
F 25 25 M 40 38 T 20 10
G 25 25 O 30 10 U 55 40
P 20 12
Q 36 36
Total 100 100 100 100
• Enter for Surface and Atmospheric Balances all the radiation fluxes that either reach them (“In”) or leave them (“Out”). You will have to determine which fluxes belong to these balances.
• Some fluxes may belong to more than one Balance
Balance to Space Surface Balance Atmospheric Balance
S PDC GC S PDC GC S PDC GC
In Out In Out In Out In Out In Out In Out
KEX 100 100 J 55 36 D 30 25
D 30 20 L 12 20 R 60 40
E 20 30 M 59 40 S 15 15
F 25 25 M 40 38 T 20 10
G 25 25 O 30 10 U 55 40
P 20 12
Q 36 36
Total 100 100 100 100 126 126 96 96 90 90 65 65
• Then calculate the Surface and Atmospheric Balances). The sum of “In” should be equal to “Out”.• Don’t be surprised if the values you obtain for the PDC are different than the ones for the GC.
Some hints• Use the flow charts as a guide to fill Table 2 • When determining which radiation fluxes belong to the balances (to Space, Surface, Atmosphere), think about whether they actually contribute any energy to this balance or if they are just passing through
• e.g.: scattering of shortwave radiation by clouds doesn’t contribute any energy to the atmosphere balance• e.g.: albedo by the ocean doesn’t contribute any energy to the surface balance
A few more hints• Suggestion: Enter in Table 2 all the Radiation fluxes
that contribute to the Radiation Balances, prior to the lab
• You don’t need the values to determine which radiation fluxes contribute to the Balances • It will take 10 minutes and save you lots of time
• Bring a calculator!• Bring your notes from the lecture on Radiation budgets
(Lecture 5)• Bring your textbook
• DON’T PANIC!!
Earth’s Radiation Budget
Part B: Questions on A2L• 12 MC questions, some with 3 parts• Involves:
• Series of questions on how to calculate specific radiation fluxes.
• e.g.: What is the correct equation to calculate net long wave radiation at the atmosphere to space boundary?
• Then using the equation you have selected, you must calculate these fluxes for the PDC and the GC
• e.g.: What is the net long wave radiation at the atmosphere to space boundary for PDC?
• Refer to the flow charts and the values you entered in them to answer these questions
Part B: Questions on A2L (ct’d)• e.g.; Q3: What is the correct equation to calculate earthshine?
• FYI: Earthshine is the ratio of reflected solar radiation (Ar + Cr + Sr) to KEX
• e.g.: What is the correct equation to calculate earthshine? (1 mark)
a. (Aa + Cr + Sr) / Kexb. (Ar + Cr + Sr) / Kexc. (Ar + Qh + Sr) / Kexd. (Ar + Cr + Sr - Aa) / Kex
Part B: Questions on A2L (ct’d)• Some questions ask you why there are differences between the balances of the PDC and the GC
• e.g.: Why is there a difference between the earthshine and net solar radiation for the PDC and GC?
• Pick the option that is correct• Refer to your lecture notes (Lecture 5) and your textbook for help• Also, think about what you would expect to be different between PDC and GC
Part B: Questions on A2L (ct’d)• Each lab section has its own set of questions, e.g. 1A03-Lab 2-Part B-Radiation Budgets- L03
• MAKE SURE TO SELECT ON A2L THE ONE THAT CORRESPONDS TO YOUR LAB SECTION
Deadlines
• By the end of your lab (week of Jan. 24th):• Completed flow charts• Table 2 completed• Everything signed by your TA
• Submit flow charts and Table 2 at the start of your lab, week of Jan. 31st
• Include a cover page
• Questions on A2L (week of Jan. 31st): • Have to be completed by the time your lab starts
Related Documents
