Final Review, NOW including material from guest lectures by Clark Kirkman and Dr. Mongtomery.

The midterm reviews are included below in revised form by shortening them(!) and slightly rewording some questions to 
improve clarity and include some answers.

* indicates material that is not necessarily covered in the textbook but was discussed in class and or lecture notes

Disclaimer: I cannot guarantee this review covers everything that will be on the test.


You will be given the following list of equations (with real symbols)

Feedback factor              f = Delta Teq / Delta To
Inverse Square Law       S = So (ro/r)2
Wien's law               lambda-max = 2898 / T
Stefan-Boltzmann Law      F = sigma T4
Planetary Energy Balance sigma T4 = S (1-A)/4
Climate sensitivity     lambda = Delta Teq / Delta F (different lambda than in Wien's law)
Residence Time  = Reservoir Size / Flux in or out

Chapter 1 (and/or lecture)

Definitions:

1. Greenhouse effect (why is it not like a blanket or greenhouse)
2. Global warming
3. Climate Change
4. Biodiversity
5. K-T Boundary

1. *What is the difference between weather and climate?
2. *What are sources of uncertainty in predicting climate?
   

Chapter 2 (and/or lecture)

Definitions:

1. Systems approach
2. *Reductionists approach
3. Component
4. Coupling
5. Feedback loop
6. Thermal equilibrium
7. Planetary albedo
8. Surface albedo
9. Self-regulating
10. Optimum temperature
11. Gaia
    

1. How is it possible that a system with positive feedbacks, like Earth, can maintain a stable climate (consider climate variability during the holocene to be stable)?
2. The feedback loop in Daisyworld has two possible outcomes depending on the temperatures. Given the components, be able to draw the two system diagrams - one for each of the possible feedback loops.
3. *Understand concept of a feedback factor with Delta To  (in equation 1 at the top of this page) is the change in temperature with IR-temperature feedback only.
   

Chapter 3  (and/or lecture)

Definitions:

1. Electromagnetic radiation
2. Wavelength and frequency
3. Flux
4. Astronomical Unit AU
5. Kelvin scale
6. Blackbody radiation
7. Effective radiating temperature
8. Troposphere
9. Stratosphere
10. Convection
11. Conduction
12. latent heat
13. sensible heat
14. Atmospheric window
15. Saturation vapor pressure (discussed in Chap 4, but belongs here)
    

Concepts:

1. Wavelength is inversely proportional to frequency and frequency is proportional to energy
2. The relative wavelength of the radiation we talked about are: UV < Visible < IR ( < = "is less than")
3. The Earth and sun have very different surface temperatures. What does this mean for the radiation that they emit?
4. What is F_IN-F_OUT = ?, averaged globally when a planet's energy budget at the top of the atmosphere is in balance?
5. The magnitude of Earth's greenhouse effect is 33 C
6. Why are clouds important?
7. Which clouds (low or high) have a greater warming effect at night, compared to a cloud-free night?
8. Why are clouds a source of uncertainty in climate prediction? Answer: Scientists aren't sure about the sign of the cloud-temperature feedback loop yet. ETC
   
9. *The feedback factor (and stability) depends on the sum of feedbacks. If the system has net positive feedback (postivite feedbacks are bigger than the negative ones), then the feedback factor is inifinite and the system is unstable. If the net feedback is negative, but there are some positive feedbacks (like in Earth's climate), the feedback factor is greater than one and the system is stable.
   
10. Know how to diagram the feedback loops in Fig 3-20, 3-21, and 3-22
11. *At present the Earth is not in perfect radiative balance, planetary energy balance is off by about 1 W/m2. The consequence of this imbalance is that we are due for about another 1 deg C of warming if we emit no more greenhouse gases. We call this warming in the "pipeline" or warming "commitment".
    

Chapter 4  (and/or lecture)

Definitions

1. Buoyancy
2. Convergence/Divergence
3. ITCZ
4. Coriolis Effect/Force
5. Continentality
6. Advection
   

Concepts:

1. Variations of incoming solar radiation with latitude Fig 4-1
2. What latitudes receive a net radiation deficit/surplus? What compensates for the deficit/surplus to maintain thermal equilibrium?
3. What drives the Hadley circulation and what are its characteristic features? How does latent heat release boost the circulation?
4. Describe the polar front zone and explain its slope
5. Describe the source of the jet stream and geostrophic winds. Why is the jet stream where it is? Answer: On a day-to-day basis it is wavy because of atmospheric waves (I know that is redundant, but its good enough).
6. What causes the seasons? Where is the greatest range in seasons? Why?
7. How different is the solar flux at perihelion and aphelion? Why is this variation in solar flux not the cause of seasons in the northern hemisphere?
8. What are the land-ocean contrasts in thermal inertia and albedo? What are the consequences for temperature and circulation on the diurnal and seasonal cycles?
9. Where does it rain most? Where are Earth's deserts?
   

Chapter 5  (and/or lecture)

Definitions:

1. Ekman spiral
2. gyre
3. pycnocline
4. thermocline
5. halocline

Concepts:

1. What causes oceans to circulate? Where is the driving source? What are the consequences of heating the ocean from above?
2. The maximum summertime temperature at the surface occurs about 30 days after solstice on land and 90 days on the ocean. Explain what causes the lag and why they differ.
3. Ocean circulations are fundamentally driven by wind, evaporation, and/or heat exchange with the atmosphere. Match the following circulations with one or more of these fundadamental sources: Ekman transport, subtropical gyre, thermohaline circulation, Antarctic circumpolar current, and sinking of dense water plumes.
4. How do gyres and the thermohaline circulation transfer heat in the horizontal direction?

Ch 7 Plate Tectonics

1. As continents drift about they have occasionaly bunched near the poles. Why is this important for climate? (platform for ice sheet formation, etc)
2. Continents have occasionally bunched near the equator. Why is this significant for weathering?
3. Where and what happens at diverging and converging plate boundaries (Fig 7-21), especally with regard to the rock cycle (Fig 7-25)?
   

Ch 8 Carbon Cycle 

1. Roughly compare the sizes of carbon reservoirs of the atmosphere, marine and land biosphere, and sedimentary rocks.
2. Describe the biological pump. How does it affect the concentration of carbon and oxygen dissolved in sea water at the ocean surface? 
3. Describe the role of plate tectonics in the the carbonate - silicate cycle.
4. In what way does the carbonate-silicate cycle serve to stabilize the temperature of the climate system? 
5. Scientists estimate that burning the entire fossil fuel reservoir (4700 GtC) might increase atmospheric concentration from 760 GtC to about 4000 GtC. What other reservoirs are likely to increase in response? How?
6. Why is the ocean expected to acidify in the future and what does it mean for animals with calcium carbonate shells?
7. How does carbon "leak" out of the short-term organic carbon cycle? How is it re-introduced to the  biosphere?

1. Why were there high levels of CO2 and CH4 in the early atmosphere? How do we know they were high?
2. More often than not in the last 500 million years it was warmer than at present. Higher temperatures are attributed to higher levels of CO2. Give three reasons why CO2 might have been higher?
3. What is the leading explanation for the reduction in CO2 during the cenozoic (past 65 million years)?
   

1. How and why do CO2 and CH4 vary with temperature during the ice ages? Would their change reinforce the ice age climate? (see p 281-282, don't struggle too long with the shelf nutrient hyp. or coral reef hyp.) 
2. Milankovitch argued that ice volume should respond to summertime insolation. How do ice sheets work? In other words why is summertime insolation (or temperature) more important than accumulation.
3. Why do scientists still debate whether Milankovitch was right? (See Fig 14-8. People insist on comparing ice volume to insolation. Instead they should compare ice melt rate to insolation -- as suggested in Fig 14-9. The fit is actually very good! I'll show this in class. )
   

1. What is the nature of the abrupt climate events? e.g., When did they occur? How many "interstadials"  were there in the last ice age? What is the interval between events and about how long did they last? What is the magnitude of the event? Have they occured in the holocene? Don't worry about the theory of stochastic resonance, few people believe in it.
2. How do volcanoes influence climate in the 1-5 year time scale? 
3. How can you reconcile the excellent match between the sunspot cycle data and temperature shown in Fig 15-8 with the more widely held belief among scientists that the 20th century temperature trend is due increasing levels of greenhouse gases?
   

Climate models

1. Provide one explanation as to why there is such a large range for future global surface temperatures projected by general circulation models (GCMs). B
2. Briefly explain the difference between equilibrium and transient climate experiments.   How does warming in the Antarctic differ?
3. What is considered to create an emissions scenario? (give at least two independent things)
   

Ch 16 Global Warming

1. Owing to the exchange rate of CO2 between biota and the atmosphere, the residence time for CO2 in the atmosphere is about 8 years. Yet if all anthropogenic sources of CO2 were halted at once, scientists expect atmospheric CO2 concentrations will not return to pre-industrial levels for half a century or more. Why so long? (see p322)
2. Fossil Fuel burning is adding about 6 Gt C/yr to the atmosphere. Deforestation and land use adds another 0.5-2.5 Gt C/yr.  The total is about 8 Gt C/yr but the atmosphere is only increasing at the rate of about 3 Gt C/yr. Where does the other 5 Gt C/yr go?
3. Given the climate sensitivity equation at the top of this document:  Explain what is meant by each symbol and what the equation means as a whole?
4. Fig 16-5 indicates that in the year 2000, the combined forcing from GHGs was about 2.4 +/- 0.25 W/m2 while the combined forcing from aerosols was -3 to 0 W/m2. What does this figure imply for attributing global warming to anthropogenic  sources?
5. If we returned to pre-industrial emission levels of CO2 today, the Earth system will reach a new equilibrium many centuries, or perhaps a few millennia, later. Why does it take so long? (Half of the answer is roughly the same as for #1 about the carbon cycle. The other half of the answer deals with ocean heat uptake.)
6. Describe very generally the pattern of global warming that is predicted over the next century in transient climate experiments (the pattern is the same as observed/modeled in the 20th century). Where do models predict surface warming is greatest and the least? Describe the hemispheric asymmetry.
7. What are the most important local impacts of global warming described in the report by the UW climate impacts group?
   
8. Explain how cost-benefit analysis is used to estimate the economic consequences of global warming. How does the discount rate affect the problem?
9. What is the Kyoto protocol? Why did Bush in 2001 say the US would not participate?
   

Ch 17

1. Know the four chemical equations that make-up the Chapman cycle to the extent that you could fill in the right hand side of the equations if given the left.
2. What is a catalyst? What is its role in ozone destruction? Which radicals are responsible for ozone destruction? 
3. CFCs are highly stable compared to natural sources of Cl.  How does this make CFCs more likely to destroy ozone?
4. What is the role of the Antarctic stratospheric vortex in establishing the ozone hole? Why isn't there an ozone hole in the Arctic too?
5. What is the role of polar startospheric clouds in ozone destruction?
6. What is the Montreal protocol? What factors contributed to its success at rallying support among nations? Has it made a difference?

1. What are the benefits of decentralized energy sources and what are some examples that are renewable?
2. Which renewables are irregular in time and why is this a disadvantage?
3. Explain how ideally biodiesel production and use can be considered part of the carbon cycle. What are the leaks in the cycle today?

1. What does slide 11 from Dr. Montgomery's lecture tell us about energy use (and hence CO2 emissions) in developing versus developed coutries now and in the future. How does this pose a problem for reducing CO2 emissions in the future?
   
2. Be able to define the three ways in which emissions are measured for each country: total CO2 emissions,  CO2 intensity, CO2 emissions per capita.
   
3. In which of the three measures do developing countries appear to be the biggest emitters?
4. In which of the three measures do developed countries appear to be the biggest emitters?
5. In which of the three measures is there about an even split of both developed and developing countries among the top 5 emitters?
6. Canada has vast oil reserves in the form of oily sand, which presently is too expensive to separate. Other than Canada, countries with the largest oil reserves are in the middle east. From a global perspective, this is a highly centralized energy source from a region with a history of autocratic or theocratic governments. Discuss the disadvantages of this situation. (this is too political for this class. It won't be on the final, but think about it)