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25 votes

Is there still a hole in the ozone layer?

Some countries are still illegally using banned chlorofluorocarbons (CFCs). "In 2018, high levels of banned chlorofluorocarbons were detected in the atmosphere that were eventually traced to ...
Fred's user avatar
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21 votes
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Is there still a hole in the ozone layer?

Why is there still a hole in the ozone layer? To some extent, there most likely will always be an area over Antarctica with reduced stratospheric ozone content in late Southern Hemisphere winter. (I ...
David Hammen's user avatar
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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
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9 votes
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ppmV versus ╬╝mol/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
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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
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7 votes
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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
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6 votes
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Photo of sprites in a clear dark sky, how is this possible?

According to this Wikipedia entry Sprites occur at altitudes between 50 and 90km while the thunderstorms that create them generally top out below 16km so there is a minimum of more than 30km of height ...
Ash's user avatar
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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
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5 votes
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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
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4 votes
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What is the characteristic time of the loss of the Earth atmosphere, how can it be calculated?

Even in the exosphere, at 1800 deg centigrade, the only components of the Earth's atmosphere that can currently attain escape velocity are hydrogen (3 kg per sec), and and helium (next to nothing). ...
Gordon Stanger's user avatar
3 votes

Now Mars is pulsing 3 times per night in the UV, can anyone explain these waves in simple terms? Do these waves have analogies on Earth?

The Martian nightglow comes from molecules in the atmosphere that react with solar radiation, carry it over to the night side, and give off the energy they gained as ultraviolet light as they free-...
Oscar Lanzi's user avatar
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3 votes

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

As an expansion of Fred's anwer: Some of these oxides in question are well recognized and intentionally used. Thus some of them are used to desinfect water replacing elementary chlorine gas. They ...
Buttonwood's user avatar
3 votes

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

Regarding the Geostationary Environmental Monitoring Spectrometer (GEMS) itself: The instrument's purpose is given as Ozone profile and total-column or gross profile of other species. ...
David Hammen's user avatar
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2 votes
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How would this experiment's different particle types produce atmospheric reflectivity?

foreword: Particles and Droplets Commonly, atmospheric particles can be considered as wet particles. E.g. when we talk about sulfate particles ($SO_4^{2-}$), these particles are actually droplets ...
daniel.heydebreck's user avatar
2 votes

Why is at high altitude more light from oxygen in the auroras while it is heavier than nitrogen?

The visible emissions from atomic oxygen take place between the fine structure levels of the ground state, and transitions between these states are not quantum-mechanically allowed by electric-dipole ...
Patrick Espy's user avatar
2 votes

Can ionospheric plasma disturbances affect the weather?

Apparently it is possible for the ionosphere to influence the conditions in the lower atmosphere. The following are relatively recent results from a paper in 2009, and a summary and up-to-date state-...
AtmosphericPrisonEscape's user avatar
2 votes

Can ionospheric plasma disturbances affect the weather?

The ionosphere is too high up to affect the weather far below in the troposphere. It's more the other way around. Lightning discharges in the troposphere sometimes send vertical columns called sprites ...
Michael Walsby's user avatar
1 vote

Effect of changes in the air's nitrogen-oxygen-carbondioxide proportions

As a follow on to Riccardo's answer, dry-air oxygen levels are fairly stable at 20.95% outdoors. The info below is based on OSHA here and here: Below 19.5% - air is oxygen deficient and one should ...
unstar782's user avatar
1 vote

Effect of changes in the air's nitrogen-oxygen-carbondioxide proportions

The (dry) air in Earth's atmosphere is about 78.08 percent nitrogen, 20.95 percent oxygen, and 0.93 percent Ar. Roughly, 78% N2, 21% O2 and 1% Ar. CO2 is a mere 0.04%. If the oxygen content were 1.1-1....
Riccardo's user avatar
1 vote

Why are red auroras rare? Why do oxygen atoms (not oxygen molecules) cause auroras while molecular nitrogen cause auroras instead of atomic nitrogen?

In fact multiple species of oxygen or nitrogen can create emissions at various wavelengths. There can be aurorae over a wide range of wavelengths, we just see only some of them that happen to be in ...
Oscar Lanzi's user avatar
  • 3,881
1 vote
Accepted

Does airglow intensity systematically change during the night?

There is a measurable decay of airglow radiance during the night. Here's an example measurement of $\mathrm{OH}^-$ infrared emissions ($\sim2\,\mathrm{\mu m}$ wavelength) done on Mauna Kea in ref. 1: ...
Ruslan's user avatar
  • 461
1 vote

What are the composition and pressure of the exosphere?

Since this is the Earth Science stack exchange I assume you are talking about the Earth's exosphere, in which case the first issue to decide is how one defines the exosphere - there are several ...
Gordon Stanger's user avatar
1 vote

Why is at high altitude more light from oxygen in the auroras while it is heavier than nitrogen?

Short answer: Oxygen atoms (not oxygen molecules) cause the dominant red and green auroral emissions at high altitudes. Although there is more atomic $\ce{O}$ at higher altitudes than nitrogen, the ...
tipavi's user avatar
  • 121

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