16 votes
Accepted

How did CO₂ originate on Earth before there was life?

The answer is Volcanos. There might be other inorganic processes capable to produce $\text{CO}_2$, but on Earth, the main inorganic source of $\text{CO}_2$ are volcanoes. In some period of Earth's ...
Camilo Rada's user avatar
  • 17.7k
15 votes

What keeps the different gases mixed in the atmosphere?

It's because gases also diffuse. If you separate two gases of different densities by a horizontal membrane, and then slowly remove the membrane, then the interface will diffuse. You can try this with ...
Wolfgang Bangerth's user avatar
14 votes

Why is it colder in the mountains than at sea level?

The traditional answer basically comes down to the physics concept of adiabatic cooling, a description of which is: There is less pressure as you go up in the atmosphere (basically due to less air ...
JeopardyTempest's user avatar
12 votes
Accepted

Can I use diamonds as fossil fuel?

Diamonds are expensive. Really expensive. Even "cheap" synthetic diamonds are orders of magnitude more expensive than conventional fossil fuel. By using them as fuel, you will increase ...
Gimelist's user avatar
  • 23.1k
11 votes

Why have "ozone-depleting substances" led to a third of all global warming and half of arctic sea ice loss?

The Global warming potential (GWP) describes how much global warming a particular gas may induce in a particular time period. It is often expressed in terms of CO₂-equivalent. The best known ...
gerrit's user avatar
  • 11.7k
11 votes

Why are atmospheric BrO and ClO important to measure by satellite?

BrO and ClO significantly deplete ozone from the atmosphere. Researchers at Harvard University state: It is a remarkable fact that perhaps the most important observation coupling climate forcing ...
Fred's user avatar
  • 24.7k
9 votes
Accepted

ppmV versus μmol/mol for atmospheric CO2 - how to convert?

According to the US Carbon Dioxide Information Analysis Center : Though in their data table they use the term "ppmv", they explain: The CO2 mixing ratios are reported as micromoles per mole ...
DavePhD's user avatar
  • 5,972
8 votes
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What "g" would be needed to keep helium on Earth?

Atmospheric escape is the loss of planetary atmospheric gases to outer space. You'd never be able to contain ALL of any gas forever by gravity. Ultimately you end up in the rarefied atmosphere where ...
MaxW's user avatar
  • 511
8 votes

Why is the Earth's shadow blue?

To my eyes, the belt of Venus looks purple, which didn't makes sense to me, as the very short wavelength of purple light should have been scattered long before arriving back there. Then all made sense ...
David Hammen's user avatar
  • 23.6k
8 votes
Accepted

Convert NO2 concentration in Sentinel-5P data from mol/m2 to μg/m3 on the ground level

...measured in mol/m² within the total or tropospheric column. Is it possible to deduce concentrations for a specific slice of the troposphere? Not really, since you have a crucial bit of information ...
gerrit's user avatar
  • 11.7k
7 votes
Accepted

Why is the Earth's shadow blue?

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 ...
Ruslan's user avatar
  • 461
7 votes

Does natural plant decomposition release more greenhouse gases than burning

Another way of looking at the question: I take 2 standard wheelbarrows of bits of plants from my garden. One wheelbarrow is used to fill the compost bin. The other goes to the bonfire. How much ash ...
user7733's user avatar
  • 544
7 votes
Accepted

How to calculate the solar radiation at any place, any time

Look at the pysolar docs (http://pysolar.readthedocs.io/en/latest/) under "Estimate of clear sky radiation". The algorithm does not return zeros at night, but instead just plugs those ...
Jareth Holt's user avatar
  • 1,381
7 votes

Have the oceans dissolved water vapour?

The answer is no, yes and then, perhaps, no. No: water vapour is not "dissolved" in the oceans, rather it becomes part of the oceans through a phase change from vapour to liquid (possibly via an ...
M Juckes's user avatar
  • 772
7 votes

How to convert mol/m^2 to total mass ( e.g gram, kg etc )?

$\rm \frac{mol}{m^2}$ shows the amount of $\rm{NO_2}$ in the atmosphere over a square meter of surface area - in mols. The molar mass of the $\rm{NO_2}$ is $14+2\cdot 16=46$. It means, the mass of 1 ...
peterh's user avatar
  • 660
7 votes
Accepted

Does evaporated hand sanitizer pollute the environment?

Assuming you are talking about ethanol: it is a common chemical substance, generated naturally from e.g. rotting fruits. So any pollution from hand sanitizers should be negligible. What happens to the ...
anatolyg's user avatar
  • 230
6 votes
Accepted

What denotes a parameterization in a model? (semantics )

As defined in the AMS glossary, a parameterization is a simplification of one or several processes in a model. I add that a parameterization commonly adds an error and increases the uncertainty in the ...
daniel.heydebreck's user avatar
6 votes
Accepted

The difference of vertical advection and convection process for chemistry species

The difference between advection and convection in Chemistry Transport models (CTMs) is a question of scale: Advection is driven by winds that are provided by the meteorological input dataset. Thus, ...
daniel.heydebreck's user avatar
6 votes

How to understand the bizarre high level for both PM2.5 and Ozone

I think it is important to keep in mind the mechanisms that form PM$_{2.5}$ are different than the mechanisms that form O$_3$. From the data your provided you can draw some simple conclusions: ...
BarocliniCplusplus's user avatar
6 votes
Accepted

What is brown carbon?

Carbonaceous aerosols are formed by a mixture of substances with different chemical, physical, and optical properties. Certain organic substances are mostly transparent to sunlight and therefore do ...
Dima Chubarov's user avatar
6 votes
Accepted

If methane decays to $\small\sf{CO_2}$ in the atmosphere, shouldn't there be much more $\small\sf{CO_2}$?

So what am I missing in this analysis? The linked data says 2017 CH4 was about 1850 ppb, not 1850 ppm. Dividing parts per billion (ppb) by 1000 results in parts per million (ppm). In other words, ...
David Hammen's user avatar
  • 23.6k
5 votes

How can scientists measure chemical composition on other planets?

Scientists can measure the chemical composition of the atmosphere of other planets using spectroscopy. Each molecule in the atmosphere absorbs and re-radiates at specific frequencies of light that ...
f.thorpe's user avatar
  • 13.6k
5 votes
Accepted

Persistence time of ozone

Let's first consider the scenario in the absence of free radicals that can act as catalysts of $O_3$ destruction. In such scenario, added to the absence of UV radiation, the photolysis of ozone ($O_3 +...
Camilo Rada's user avatar
  • 17.7k
5 votes

How is the equilibrium of 21% oxygen in Earth's atmosphere established?

Atmospheric oxygen is not in an equilibrium of 21%, it just changes very slowly. For instance, oxygen has decreased by 0.7% over the past 800 thousand years, likely due to increased erosion (which ...
f.thorpe's user avatar
  • 13.6k
5 votes

Why have "ozone-depleting substances" led to a third of all global warming and half of arctic sea ice loss?

Do these "ozone-depleting substances" also have infrared-absorbing greenhouse impact unrelated to their ozone-depleting chemistry, or is the story more complex? Yes, the paper (I have access) ...
y chung's user avatar
  • 704
5 votes
Accepted

Have the oceans dissolved water vapour?

TL;DR: Henry's law describes an ideal linear relationship between the equilibrium amount of a low-concentration solute in a solution and the partial pressure of the solute in the gas phase above the ...
haresfur's user avatar
  • 4,419
5 votes

Why are atmospheric BrO and ClO important to measure by satellite?

pretext: Seeing this question on the list of network questions caught my interest to the site. I agree with the arguments put forward in the answer by Fred, gravitating on the radical character of ...
Buttonwood's user avatar
5 votes

Are atmospheric halogen oxides "supposed to be" in the atmosphere? Where do they come from?

Classifying the presence of halogen oxides in the atmosphere as either natural, pollution or mixed bag, would result in mixed bag. Natural sources of halogen oxides include the ocean and volcanoes. ...
Fred's user avatar
  • 24.7k
5 votes
Accepted

Why is there a window in the absorption spectrum of Earth's atmosphere at a wavelength of 4 μm?

There is simply no strong enough absorption of any of the greenhouse gases at this wavelength. However this does not mean that there is none. Remember that what you are seeing here is the transmission ...
AtmosphericPrisonEscape's user avatar

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