Allen+Notes+and+Research

** GREENHOUSE EFFECT: **
1. The sun shines on the Earth 2. Protons with energy go through the atmosphere as Visible Light 2. The sun's rays reaches a part of the Earth (ground, clouds, etc.) and is partially reflected. That of which is not reflected remains on the Earth as energy. 3. The reflected rays form a blackbody, which emits IR rays. Some hit Greenhouse Gases which again reflect the rays back to Earth, "trapping" the rays and hence keeping more energy on the Earth. Note that Greenhouse Gases do not block Visible Light but do block IR rays

=GOLDILOCK PRINCIPLE=

The Earth, Venus and Mars are three planets that are well situated to benefit from the energy output of the sun, yet all 3 have very different atmospheres and surface conditions. Scientists who first probed the potential of increased greenhouse gass effects on Earth’s climate looked for clues about our future by examining the conditions on our nearest neighbors. Complete this table. //Be sure to include a complete reference and URL for any sources you use to find the necessary information//.


 * Atmospheric Gas ||  Venus  ||  Earth  ||  Mars  ||
 * Carbon Dioxide ( percent || 96.5%  ||  0.03%  ||  95%  ||
 * Nitrogen (N2) ||  3.5%  ||  78.08%  ||  2.7%  ||
 * Oxygen (O2) || trace  ||  20.95%  ||  0.13%  ||
 * Argon (Ar) || .0007%  ||  0.93%  ||  1.6%  ||
 * Methane (CH4) || 0  ||  .000179%  ||  0  ||
 * Surface Pressure – Relative to the Earth ( in bars) || 90  ||  1 (duh)  ||  .0007  ||
 * Major Greenhouse Gases (abbreviated to GHG) || CO2  || H2O, CO2 ||  CO2  ||
 * Actual temperature © || 477  ||  15  ||  -47  ||
 * Temperature if no GHG © || -46  ||  -18  ||  -57  ||
 * Temperature due to GHG ( C) || +523  ||  +33  ||  +10  ||

The findings of scientists review evidence about the three planets is often referred to as the “Goldilock’s Principle” after the Fairytale character of that name’s response to each of the items she found in the three bears home while they were out for a walk.

Missing from the table is information about the difference in surface presssures on each of the planets that account for the “amount” of atmosphere that is found on each. Compared to Earth, Venus has 90 times the surface pressure while Mars has 0.007 times the pressure.

From examining the contents of the completed table, what do you think explains the differences between Earth and its neighboring planets?

Venus is the high extreme, with huge pressure, temperature, and other stuff. Mars is the exact opposite, with barely any atmosphere. Earth is just right, with perfect surface pressure and temperature.

Earth has levels of all these categories in the middle of a vast spectrum, of which Mars and Venus encompass both ends quite well. The particular categories that make a huge difference are atmospheric content (CO2 alone is not suitable for such a wide variety) and temperature (so that liquid water exists.

=CHAPTER TWO=

1. 100*60*60*24 = 8640000 W. 30*10^6*3/10 = 9*10^6 = 9000000 J. Hence, it requires a little under a kilogram.

2. Yay Fermi Question

Clearly, there cannot be 1000 corns in a meter square, since that would be one every 10 centimeters squared, which is about the size of a touchpad on a computer. Also, there cannot be 10 corns. Hence, we will estimate it at 100.

In addition, we can guess that there are 100 kcals in an ear of corn. That means, in a meter square, there are 10,000,000 calories, or about 2.4 million joules. A season for growing corn is about 100 days. Hence, since there are 250*86400=21.6 million Joules a day, the efficiency is about 0.1%.

3. 7*10^9*1000000 = 7*10^15 J, 3.5*10^6 seconds, or 40.5 days. There are about 640 million meters squared in that pond. If its 12% efficient, its 30W/m^2. That would be about 30*640,000,000 ~ 20,000,000,000 J. 10 times more than the dam.

4. 2*10^9/ 30 W/m^2 is about 771 days

5. k = 1/w = 10^5 cm^-1.

f = 1/T = 1/(.5*10^(-5)/3*10^8) = 6*10^13.

100,000,000 = f. T = 10^-8. T = w/c = w/3*10^8. 3 = w

=**CHAPTER THREE** =

1) What does Fin = Fout mean in this model. Use your own words Fin means the energy flux in: that is, from the sun to the earth. Fout is the opposite: the flux from the earth outwords.  2) Why do you measure the size of the shadow cast by the Earth when the Sun shines on it to calculate the intensity of the energy heating the Earth? For one instant of time, look at the rays emitted by the sun. Then, right before the photons hit the Earth, they are in an array of a shape of a disc traveling straight at earth. Hence, the intensity is measured by the shadow (alternatively, you can argue that on every point that the sun's rays hit, the intensity is actually also determined by the slope of the earth and do some calculus) 3) Show the calculations to determine the temperature of Venus and Mars using the data in TABLE 3.1. Are these the measured temperatures on Venus and Mars? Why or Why not?  Essentially, we can simplify the equation to, if Tp is the temperature of the planet,  Tp = fourthrt((1-alpha)*Iin/4*epsilon*sigma)  We can express Iin as epsilon*sigma*Tsun^4*R^2/Dp^2, where Dp is the distance from the sun to the planet, and R is the radius of the sun. The R/Dp squared is added because the 'sphere' of light expands, lowering the intensity Then,  Tp = Tsun*fourthrt(1-alpha)*sqrt(R/2Dp).  Tvenus = 5780K*fourthrt(0.30)*sqrt(696*10^6/(2*108*10^9))=242K = -31 degrees C Tmars = 5780K*fourthrt(0.85)*sqrt(696*10^6/(2*228^10^9))=217K = -56 degrees C    WELL i thought we were supposed to answer the questions from the book .__. anyways,    1) The moon's dark side should be absolute zero, and when it is directly overhead, it is slightly more complicated. We can say that Fout = A*epsilon*sigma*T^4. Also, Fin = A*(1-alpha)*Iin. Then, T = sqrt(sqrt((1-alpha)*Iin/(epsilon*sigma))  alpha = .12 Iin/epsilon*sigma = 5680^4  Hence, we get Tmoon = 5501K  2) a) Iup,layer 2 + Idown,layer 2 + Idown, layer 1 = Iup, ground Iup, layer 2 + Idown, layer 2 = Iup, layer 1 Iup, layer 2 = Iin, solar b) as with skin temperatures, we look at just the last equation, and T2^4=(1-alpha)Isolar/(epsilon*sigma)  c, d)Iup and Idown are the same for both layers. Hence, fourtrt(2)T2 = T1 sqrt(2)T2 = Tground  the greenhouse effect is stronger  3)Isolar = Iup, atmosphere  which is the equation of bare rock  Which means, Tatmosphere = -18 celsius (as derived before)  Hence,  Iup,earth = Idown,atmosphere  Hence, it would be about -18 celsius

Lab DaisyWorld: Questions
The purpose of these questions is only to suggest games to play with the simulator. Do what's fun.
 * 1) In the first scenario, "DaisyWorld in 3 species", you'll notice that the living area ("total daisies") doesn't exceed 70%. Look at the Parameters of this scenario. The deathrate is set to 0.3, which may explain the living percentage being no more than 0.7. Play with this parameter. What does the deathrate do to the daisies' ability to control their environment's temperature? To the species mix?

It decreases their ability, as the number of Daisies will lower. I am unsure what the second question means, but White becomes more populous and Black becomes less populous, while the middle stays about the same.


 * 1) Using a multispecies scenario you like, run the insulation from 0 to 1.0 by .2's. What effect does this have on the daisies' control of the planet temperature? Why? If DaisyWorld had spatial structure, neighboring patches of daisies, and the neighbors were more influential (lower insulation) than the planetary temperature, what might be different?

It decreases it, as each daisy has better control over its section which it wants to optomise. If the neighbors were more influential, assuming their optimal temperature is the same, the planetary temperature would be that optimal one


 * 1) Another parameter is "max steps per". At each luminosity increment, DaisyWorld runs "to convergence", or a maximum of "max steps per" calculations at that luminosity, before plotting a point. Try setting this down from 1000 to 5. Where does the result differ from the original scenario? Try DaisyWorld in 5 species with max steps set to 1, 2, 3, 4, 5, 20, 50, 100. Speculate on what's going on. (Note: this is a deterministic simulation, no random component. The exact same parameters yield identical results.)

The grpah seems more chaotic due to lack of accuracy


 * 1) Wanna see something really pretty? If your computer isn't struggling too hard to run the bigger scenarios, try DaisyWorld in 20 species, changing the deathrate to 0.2 and "max steps per" to 2. You could intellectualize about this pattern if you want, or just enjoy it and see if you can come up with others.

Okay


 * 1) Try the next three scenarios (neutral, white, black). They all have barren plus one species of daisy. Pick one and experiment with the albedos from the "Daisies" button. Recall that 0 is a black hole and 1.0 a perfect reflector of incoming light. Play until you can roughly predict what's going to happen with each change. You can play with the temperature ranges on the parameter menu along with this.

Neutral

Okay, it seems that the daisies get closer to barren as, well, their albedo gets closer (WOAH)


 * 1) Going back to the 3-color base scenario, play around until you can characterize when the living world temperature crosses from above to below the dead world temperature. Does your story have predictive power? Try your predictions on a different scenario.

IT IS THE POINT OF NO RETURN. It is when the Black have no more use for absorbing, the the White find a use in reflecting. It is when the world grows too hot to handle.

> Not really: as the sun increases, things with more albedo are better (snow) > > > > || deep water || .05 - .20 || > || desert || .20 - .35 || > || short greenery || .10 - .20 || > || dry vegetation || .20 - .30 || > || summer conifers || .10 - .15 || > || deciduous forest || .15 - .25 || > || snowy forest || .20 - .35 || > || dry snow || .60 - .90 ||
 * 1) Here are some albedo values for planet Earth. Play around with them, perhaps with the 3-species scenario, using desert values for "barren", since barren is all that is not daisies. Learn anything?
 * ~ Ground cover ||~ Albedo ||
 * 1) Some Earth features missing in DaisyWorld are an atmosphere and roundness. Solar input is not the same at all lattitudes or altitudes, the atmosphere serves as a greenhouse, and the neighborhood temperature is definitely more influential than that of the planet as a whole. What might this explain about your results with the Earth albedo values above?

It is why snow is common in the north and south and not in the center, and deep water, summer conifers are good in the center


 * 1) Try the scenario of DaisyWorld in 12 species. Pose an evolutionary argument for species succession in this scenario.

YOU MUST BE ABLE TO STAND THE HEAT IN ORDER TO WIN, and the most optimal colour for a certain heat will rise.


 * 1) Refute your evolutionary argument above. Having argued both sides, which is "right"? How could you tell?

CAN 1 SPECIES OVERPOWER 11 MORE

Yes, because with a significant advantage, they will grow faster than any other group.


 * 1) In the many-color worlds (9 and above), there are sometimes pre-peaks of a color before its decisive succession. Can you come up with a story about that?

It is when colour #x switches to colour #x+1, and there is little of either, so the next in line (#x+2) has a short leap


 * 1) Stories like the ones you're inventing here are sometimes called "just-so stories". Do you think you could tell a "just-so story" from a valuable one when reading a scientific paper? How do you think people develop that kind of discernment?

Yes, just-so seems to be fabricated just to fit the data, while the valuable one seems to go beyond.


 * 1) //Time-consuming, for the mathematically inclined.// Try doing a qualitative analysis of the behavior of the system of equations [|Under the Hood.] This is a feedback loop, so try placing the equations as boxes on a circle, and determine when each has a positive (amplifying) or negative (damping) feedback on the planetary temperature. Note that the authors of this model deemed the system insoluble, so this is only a//qualitative// analysis. Can you make any predictions and test them out on the simulator?

?

=Chapter Four #1=

1a) 10 additional ppm is more important in methane than in carbon dioxide, as methane is 30 times more powerful than CO2, since methane is not saturated as the current level is lower. b) Methane absorbs at about 1300 cycles/cm c) Due to the logarithmic nature, the concentrations of methane and CO2 do not matter. However, as CO2 lies more with the radiation of the earth, the doubling of CO2 will have more effect. In the end, from 287.844 W/m^2, methane lowered it to 287.09, and CO2 lowered it to 284.672 d) A doubling of methane lowers it by 0.754 W/m^2. A ppm of 444 for CO2 achieves the same result. As such, an increase of 69 ppm will work.

=#3=

3a) When the ground temperature is increased, several things happen. Iout increases (for my values) about 3.6 w/m^2. The intensity seems to increase significantly. b) Flux is LOWER from 3.6 to 2.1,. Earth is more sensitive: a larger change in temperature is needed to match the change in IR c) 287.844 ->287.498 pCO2. 1.000 -> 0.982 water vapor returns it to 287.844.If we then change pCO2 from 375 to 405, we get 288.21 -> 287.844 . These are changes of 0.346 and 0.374.

