Questions tagged [atmospheric-chemistry]

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4
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0answers
103 views

What are 'sulphate particles' in the context of atmospheric chemistry?

This informative answer describes some processes in atmospheric chemistry and mentions "sulphate particles". Actually I realize that I don't know what a 'sulphate particle' really is, though I've ...
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1answer
438 views

How can scientists measure chemical composition on other planets?

How can scientists measure chemical composition (oxygen, nitrogen etc) and temperature on other planets without being there?
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0answers
53 views

How can the hydrosphere be properly used to reduce the load on the lithosphere [closed]

The earth is made up of 70% hydrosphere and 30% lithosphere.The space of lithosphere is continually used and it seems there is a threat to a balance ecosystem.Describe how the hydrosphere can be make ...
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3answers
9k views

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

For a uniform mixture of ideal gases, I think that the concentration of a gas reported in parts per million by volume (ppmV) and micro-moles per mole (μmol/mol) would be the same. When I see ...
7
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1answer
226 views

Persistence time of ozone

Ozone is formed in the upper atmosphere by ultraviolet light, and broken down by ultraviolet, spontaneous reactions and artificial pollutants among other things. Suppose there were no artificial ...
7
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1answer
80 views

How to relate the backward trajectories with offline particular samples?

To correlate chemicals in aerosols emanating from certain sample points, backward trajectory analysis is usually applied for identifying the potential geographical source region. In this figure ...
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0answers
21 views

What is meant by controlling and reacting factor? [duplicate]

I'm interested in issues related to Global warming and therefore started to read about it from this website -->> link As I was reading I got stuck in the third paragraph of ...
3
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1answer
88 views

How would this experiment's different particle types produce atmospheric reflectivity?

The MIT Technology Review news item Harvard Scientists Moving Ahead on Plans for Atmospheric Geoengineering Experiments discusses a proposed experiment to study in a carefully controlled way the ...
3
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0answers
95 views

What geographical areas are NOx sensitive/limited (with regard to ozone)?

Have there been any air quality modeling studies regarding the locations where ozone is considered "NOx limited" (increasing NOx increases ozone) or "NOx sensitive" (decreasing NOx increases ozone)? ...
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0answers
36 views

Is there any method to analysis the variation of chemical species removing the meteorology condition

Here is my question. The concentration of atmospheric species is decided by three major components: The source related to natural or anthropology activities. The chemical pathway of the formation ...
7
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1answer
573 views

What "g" would be needed to keep helium on Earth?

I know that helium is a very light and rare gas on Earth because Earths gravity is not strong enough to keep it. Instead, helium and hydrogen are rising through the atmosphere and escape into outer ...
6
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2answers
86 views

Does hydroxyl radical chemistry in air quality models create numerical stability problems?

Atmospheric mixing ratios of the hydroxyl radical have relatively short lifespans (on the order of microseconds). When modeling air quality or the weather, the time step is usually much larger than ...
6
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2answers
242 views

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

Background Eastern China now (2017.01) are suffering severe haze with striking concentration of PM2.5. Haze, with low visibility and complex chemical components threatens billions of persons' health. ...
4
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1answer
84 views

The higher value range for the same satellite product (NO2_OMI_TEMIS)

I'm dealing with NO2 column density of troposphere, and my data source is TEMIS. The NO2 level3 data can be derived from the original information of OMI instrument. I have downloaded two types of ...
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2answers
8k views

Is oxygen spread equally on Earth's surface?

We know that oxygen comes from trees and plants (photosynthesis), so in the jungle where there are a lot of trees you would expect more oxygen than in the desert where there are no trees. Walking in ...
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1answer
4k views

Why is the sky bluer in winter than in summer?

I don't know why, but I have noticed my whole life that the sky's blue color seems saturated in winter and sort of pale, milky, and washed out in the summer. Does it have to do with the angle of the ...
8
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1answer
1k views

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

I have heard numerous reasons why that is. I just want to know which one is right.
5
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1answer
352 views

What is principle of inverse modeling?

I read a few paper related to emission inventory talking about the inverse modeling. It was another method to estimate the emission from ground(called top-down ...
5
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0answers
100 views

Dig in the rationality of model evaluation of WRF with land-based station data

I use WRF (Weather research and forecasting) model for in regional scale meteorology simulation. And then, the WRF output files will be deemed as criterial input data applying for chemical transport ...
3
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1answer
105 views

What denotes a parameterization in a model? (semantics )

I know that WRF has many different uses and options, from atmospheric chemistry to uses with fires, and so on. What exactly denotes a parameterization? For example, in WRF-Chem, is the chemistry ...
3
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0answers
105 views

Correlation analysis with primary air pollutants and secondary formed ozone

The Ph.D dissertation Assessment of air quality in Northern China by using the COSMO-ART model in conjunction with satellite and ground-based data which was written by Stefanie Schrader in KIT German....
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0answers
282 views

How to transform the inventory data from degrees to kilometers

First all, my question was different from the question Converting grid resolution from degrees to kilometers. In chemical transport modeling, the pollutant source inventory was an essential input ...
6
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1answer
448 views

The difference of vertical advection and convection process for chemistry species

In atmospheric, the change of mixing ration $C_i$ of a chemical species $i$ is determined by: $\frac{\partial C_i }{\partial t} = -\bigtriangledown (VC_i)+\frac{\partial }{\partial z}(k_z\...
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0answers
108 views

Dry deposition of the total sulfate deposition in forested region

Sulfate is one important inorganic aerosol in the atmosphere. It's subject to removal by two main mechanisms. Wet deposition which include rain/wash-out and cloud deposition. Dry deposition ...
10
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1answer
2k views

Does natural plant decomposition release more greenhouse gases than burning

I understand that all plant matter releases CO2 as it decomposes and also when it burns in, for example, a forest fire. My assumption, upon which this question is based, is that the CO2 release is the ...
10
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2answers
3k views

What keeps the different gases mixed in the atmosphere?

Consider a gas centrifuge holding two different gases. After spinning for a while, the heavier gas will move to the outside, and the lighter gas will be on the inside. In other words, we have ...
10
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1answer
274 views

What principles do we consider when selecting an air pollution monitor location?

I'm working on a project aiming at finding some potential point as a new air pollutant monitor site for a city to measure $SO_2$, $NO_2$, $PM_{2.5}$, etc. After modeling the surface concentration of ...
9
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1answer
1k views

What's the background concentration of trace gas/pollutants?

I have read a paper discussing the concentration of air pollutants and their background concentration. In the paper Characterization of background air pollution exposure in urban environments using a ...
4
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2answers
279 views

How is there enough $\ce{O2}$ in the atmosphere to breathe if you are in a desert with no plants?

Humans depend on $\ce{O2}$ for breathing. The source of $\ce{O2}$ is photosynthesis by plants or cyanobacteria in the ocean. How is it, that when people travel through deserts or the Arctic / ...
3
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1answer
790 views

The free oxygen (O$_2$) in the atmosphere is largely a result of what process?

Does it come from a)atmospheric lightning and ozone dissociation. b)meteorite impacts early in the earth's geological history. c)Paleozoic volcanic activity. d)photosynthetic processes. e)...
5
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1answer
241 views

What would a planet's sky look like with different chemical compositions, such as low nitrogen, high methane etc?

What are the processes, chemicals and particles involved in creating colour in a planet's sky? Could you give some examples of sky colour processes different from what happens on Earth?
6
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1answer
104 views

What is the ratio of infra-red light absorbed by green house gases?

I know that some gases like CO2, N2O and CH4 absorb infra red radiation. What is the proportion or percentage of radiation absorbed by CO2 among all the gases?
7
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1answer
1k views

What causes smog to clear up on some days?

I notice that in my town sometimes the pollution/haze/smog sticks around on some days but then on others the sky can be completely clear. I don't necessarily see any difference between windy and non ...
5
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3answers
17k views

What is the difference between a carbon sink and a carbon reservoir?

I am trying to figure out the difference between a carbon sink and a carbon reservoir. The definition for a carbon sink from Wikipedia is carbon sink is a natural or artificial reservoir that ...
16
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2answers
2k views

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

The atmosphere is 21% oxygen. I assume that there must be an equilibrium between processes that produce oxygen (e.g. photosynthesis) and those that consume oxygen (e.g. aerobic respiration). Moreover,...
7
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1answer
122 views

What causes the semi-annual mesospheric meteoric potassium variability?

In a recent study presented in the article First global observations of the mesospheric potassium layer (Dawkins et al. 2014), space-borne resonance fluorescence observations confirmed previous LIDAR ...

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