7

How can the air in the Earth's shadow scatter blue light if it doesn't get any direct illumination, and any indirect illumination getting back there should be VERY depleted in blue (i.e. mostly red light)? You're completely right. If you simulate light scattering only, you'll get exactly this result: a sandy-colored sky, with a bit redder belt of Venus, and ...


5

The factor of 1000 may be related to the expected units. The mass 'units' can be found in the derivation. The full derivation of mixing ratio goes like this $$w=\epsilon\frac{e}{P}$$ since, by the ideal gas law, $$e=\rho_vR_vT$$ and $$P_d=\rho_dR_dT$$ then the mixing ratio is expressed as $$w=\epsilon\frac{\rho_vR_vT}{\rho_dR_dT}=\epsilon\frac{\rho_vR_v}{\...


3

First, let's acknowledge this fact: $$c_p=R+c_v \tag{1}$$, where $R$ is the specific gas constant. This means that $x=R/c_p$. Rearranging the equation, we can see that $$P+I=\int{c_p\left(\frac{P}{P_{00}}\right)^{R/c_p}\Theta dM}\tag{2}$$ Notice that $\left(\frac{P}{P_{00}}\right)^{R/c_p}$ is the Exner function. By extension,$$P+I=\int{c_p T dM}\tag{3}$$ If ...


2

A brief review of recent non-paywalled available literature indicates that such an effect likely exists but that it is difficult to quantify based on currently available data. Some amount of carbon from trees can be sequestered in the soil for periods time significantly longer than the typical above-ground decomposition time of organic matter, potentially ...


2

There are other greenhouse gasses besides carbon dioxide (in particular water vapor) but in order to give a definite answer, let's pretend the atmosphere is completely free of them. In this case, it's easy to calculate the average temperature of the earth by holding the incoming shortwave heat flux at its present value and assuming that it is balanced by ...


2

The concentration of CO2 in the Earth's atmosphere has remained less than 1% in the past 470 million years when land plants first appeared--long before mammals, and long before humans graced the earth. If we are talking about having a biosphere comparable to the one we know, we need to be talking about CO2 and global average temperatures that are comparable ...


2

Yes, the deterministic GFS model (one model) has higher spatial resolution than the GEFS models (31 models). That is, that the latitude and longitude of the entire world is incremented by 0.25° in the GFS and 0.5° in the GEFS (they upgraded both in the past two years). When people say "high resolution," think of it like "more pixels" on a ...


2

Looking at other planets in the solar system is a good way to get an indication of the role extreme variations of CO2 has. Mercury is closest to the sun, and has a high maximum temperature (449 centigrade) but a very low minimum (-170 centigrade). It has practically no atmosphere, and virtually no CO2. Venus, on the other hand - the planet between the Earth ...


1

Without CO2, Earth would be as cold as Mars or the outer planets between 200-250 degrees Kelvin (-80 degrees below zero fahrenheit) As for more, a 20% gain in current CO2 would be 504 Parts per million in Atmosphere. That's impossible without a century timeframe. But temperature predictions have failed to coalesce. Namely computer models that fail to predict ...


1

Specific gravity of a homogeneous material is the ratio of the material's mass density to that of water. So, specific gravity is a useful "expression" of density since the comparison to water conveys a more practical "feel" for a material's density than does a value such as kilograms per cubic meter or slugs per cubic foot, etc.


1

Depiction of global carbon in gigatons (Billions of tons) Origin


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