Marissas+Notes+and+Research

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**Greenhouse Effect﻿**
Date? In the past decade, our global temperature has risen a significant amount and more than it ever has in any decade throughout the recorded history of weather. Today, most scientists attribute this, global warming, to the effects of greenhouse gases and the greenhouse effect in our environment. The greenhouse effect is essentially the trapping of gases inside our environment causing the global temperature to increase. Because of the way our atmosphere is designed, the sun’s rays bounce off the earth’s surface and are deflected back into space. However, the buildup of gases inside our atmosphere can prevent the heat from the sun’s rays from escaping. The most abundant gas built up in our atmosphere contributing to global warming is water vapor, and the second is carbon dioxide. Carbon dioxide is most definitely produced by humans and contributing significantly to the greenhouse effect. Carbon dioxide is produced from the burning of things, including petroleum, coal, and other fossil fuels, which are integral items in our everyday society. This building up of gases in our atmosphere increases the greenhouse effect, in turn, increasing the temperature of the earth, also known as global warming.

Greenhouse Effect- Take II
October 5, 2010

The best way to explain the greenhouse effect is the way it is described in Chapter three, throught the layer model. The layer model consists of the bare rock model, and then factors in the atmosphere. The bare rock model will calculate the temperature of a piece of bare rock, without an atmosphere, floating in space. Once the atmosphere is factored in, the greenhouse effect is shown. The best way to descibe it is like a sheet of glass above the earth. When the light enters the atmosphere and earth from space, the light penetrates all the way down to the earth, once it bounces back up, only some of the light is able to bounce through the atmosphere again. Some light gets trapped inside the earth's atmosphere, creating the same effect that happens when you car sits in the sun for a while. The atmosphere becomes heated up, just as your car does. All of the visible light enters the car, and infrared heat becomes trapped inside, heating up the car drastically. Every object has some degree of infrared heat, but it is not all necessarily hot enough to be visible. There are some molecular interactions (such as those of water vapor and carbon dioxide explained in the above version of this) that can help to explain this greenhouse effect, but the panel of glass analogy is much easier for me to remember and relate to.

**Goldilocks Principle Assignment:**
Date?  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 gas es 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% || 2.7% ||
 * Oxygen (O2) || Trace || 21% || 0.13% ||
 * Argon (Ar) || 0.007% || 0.9% || 1.6% ||
 * Methane (CH4) || 0% || 0.002% || 0% ||
 * Surface Pressure - Relative to the Earth ( in bars) || 90 || 1 || 0.007 ||
 * Major Greenhouse Gases (abbreviated to GHG) || CO2 || H2O, CO2 || CO2 ||
 * Actual temperature © || 470C || 15C || -50C ||
 * Temperature if no GHG © || -46 || 15 || -47 ||
 * 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?

Hey Marissa: __** You didn't answer the question above. Why do you think, for example, the surface temperatures on each of the planets are so very different? If you don't see a good explanation in the data you grabbed from the Internet, perhaps one of the website you cite below has some ideas about this? **__  Works Cited: "10 Earth, Venus, Mars - 1." //LASP:Laboratory for Atmospheric & Space Physics//. Web. 30 Aug. 2010. . "Activity 1 Teacher Guide: The Goldilocks Principle." //UCAR | Understanding Atmosphere, Earth, and Sun | Home//. Web. 30 Aug. 2010. . Page 17 Questions 1 and 2 August 31, 2010 1) 8,640,000J/ day x kg/9,000,000J = .96kg/day 2) 250J/sm^2(1 cal/4.186J) (60sec/1min) (60min/hour) (24hrs/1day) (100 days/season) = 516,005,733.4 cal/m^2 in one season 516005733cal/m^2 (1m^2/30 ears) = 17200191cal/ear (1kcal/1000cal) = 17200 kcal/ear 17,200/516,005,733 = 3.33 x 10^-5 or 0% efficiency. = The Layer Model- Chapter 3 = September 26, 2010 1) The Fin = Fout views the planet as a closed system meaning that all the incoming energy, Fin equals the energy going out, Fout. This equation is the first assumption of the layer model. 2) Intensity is measured in W/m^2, where m^2 is the area of the shadow cast by the planet, Earth in this case. Intensity varies based on location relative to the sun and the altitude. The area of the shadow is a direct effect of the angle of incoming light from the sun. By measuring the area of the shadow, the variation of intensity due to location and altitude are removed and a more accurate prediction can be obtained. 3) These temperatures are only an approximation because the equations neglect the atmospheres of Mars and Venus, also called the bare rock model. Layer model without atmosphere (bare rock model)- (I had a pretty equation from Word equation editor here, but it wouldn't show up) T(Mars) = ((1-alpha)*Intensity in) / 4*Epsilon*Sigma) Given where alpha is the albedo-in percent, epsilon is the emissivity, and sigma is the Boltzmann's contant. The emissivity of a perfect blackbody is 1, but is related to greenhouse gases and atmosphere. So, since this is the bare rock model and neglecting atmosphere, epsilon is not taken into account. Therefore: T(Mars) = ((1- .17) * 600) / 4*5.6703x10^-8) ^1/4 T(Mars) = 216.4665 degrees Kelvin T(Venus) = ((1-.71) * 2600) / 4*5.6703x10^-7) ^ 1/4 T(Venus) = 240.1189 degrees Kelvin = Chapter 3: Part II = October 4, 2010 1) The budget equation for the atmosphere, without numbers to complicate it, simply says: I up, atmosphere + I down, atmosphere = I up, ground The budget equation for the ground is: I up, ground = I in, solar + I down, atmosphere. So, with a little algebra the equation reads: I up, atmosphere = I in, solar 2) Essentially, once the equations are worked around and solved out, T atmosphere = T bare earth. This helps to demonstrate the skin temperature of the Earth, the skin temperature is the temperature of the place in the Earth system where the temperature is most directly controlled by the rate of incoming solar energy is thetemperature at the location that radiates into space. This is important because it helps show us that the temperature of Earth rises until the fluxes balance again, as in the sink example given in the text. The "skin temperature" is the temperature of the layer where IR from Earth is no longer absorbed by the atmosphere. This means that past the skin, the energy is lost to Earth. The skin is just an artificial upper limit to the Earth. It is the space, and whatever is in the space, between the surface of the Earth and the top of the atmosphere. The concept is important to modeling efforts because the energy entering the skin coming from the Sun must balance the energy come out of the skin not matter what is in between the surface of the Earth and the outer surface of the skin. That means that, among other things, the temperature below the skin has to "adjust" to ensure this balance. It is significant to the Layer Model because it must be equal to the amount of incoming radiation if the amount of energy on Earth is to remain stable. 3) The temperature of the moon when the Sun is directly over head is 5501 K, and the equilibrium temperature on the dark side of the moon would be 0K since there is no heat transfer without an atmosphere.

=﻿Daisy World Lab= October 12, 2010

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? ﻿The death rate decreases both species mix and ability to control the temperature. As the death rate increases, the length of sustained temperature decreases as does the species mix. 2) 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 the neighboring patches of daisies, and the neighbors were more influential (lower insulation) than the planetary temperature, what might me different? As the insulation increases from 0 to 1.0, the daisies' ability to control their temperature decreases. The temperature remains fairly constant while the insulation is still low, and as the insulation approaches 1, the variablity increases and the slope of the line nears 1. 3) Another parameter is "max steps per". At each luminosity increment, DaisyWorld runs "to convergence", or a maximum of "max steps per" calculations at that luminsoity, 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 temperature is averaged just over 20 degrees C for 1000 and goes from an average at about 30 gradually down to just over 20 as the max steps get larger. The total daisy population stays at about 70% area thoughout the every step change.  ﻿4) Wanna see something really pretty? If your computer isn't struggling too hard to run the bigger scenarios, try DaisyWorld in 20 species, changin 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. 5) 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 is 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.  6) 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 predictive power? Try your predicitions on a different scenario. 7) 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?  Seeing the data in the DaisyWorld helped, but it made sense. The higher albedo regions will be lighter, the more barren regions without vegetation or snow, will have a lower albedo and in turn, be hotter.    8) 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? The highest albedo is the snow, which reflects the most light, and has the coolest temperature. The reflected light helps to keep the region cooler, and hence "snowier". The same condition applies to the short greenery. When we looked at IR photos of our schools, the bare ground had the highest IR levels, and the lowest albedo. Because there was a low albedo, more light was being absorbed, and thus more heat. 9) Try the scenario of DaisyWorld in 12 species. Pose and evolutionary argument for the species succession in this scenario. The higher albedo daisies survive longer and eventually the luminosity becomes too much and even the highest albedo white daisies die off leaving the barren land.   10) Refute your evolutionary argument above. Having argued both sides, which is "right"? How could you tell? I believe this is a probabe argument. Natural selection, the daisies with the best albedo will survive the longest, and repopulate the most. 11) 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?  In each scenario, for 9 and above, the overall pattern seems to be exactly the same, there are a few small peaks in the begining, then a "decisive succession" can be seen and a few will end up reaching the maxiumum of 70%, the temperature on all of the diagrams seems to remain at about the same, just about 20 degrees C. A possible explaination for these pre-peaks could just be simple evolution. Possibly some bloom earlier, lose some reflective properties, and end up dying off because of it? Any number of situations are possible for this one.   12) 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 descerment? When reading a paper, unless you have background knowledge stored away in your head, it may not always be easy to tell a "just-so story" from a valuable one. The best thing to do is to look for resources, experiments, data, etc that can physically back up the story. If not, then it could be a "just-so story". 13) //Time-consuming, for the mathematically inclined.// Try doing a qualitiative 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 planteary 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?
 * **Ground Cover** || **Albedo** ||
 * 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 ||

Chapter 4 Question 3:
November 10, 2010 3a) The I-Out changes to 3.67 W/m2 and the intensity will increase.   3b) The new I-Out change is 2.19 because the model holds water vapor at a constant relative humidity which causes a lower I-out level. Which means the earth is more sensitive to CO2 increases. 3c) The change in T must be .12 degrees with constant pressure and .2 degrees using constant relative humidity.