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Questions tagged [atmospheric-chemistry]

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Moving colored lights

In the summer of 2016, by night at 9PM, I saw weird moving colored lights at a height of about 8 to 15m. They were moving back and forth in the same region, and at the same height from the surface of ...
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What are the benefits of direct sun viewing spectrometer over a backscatter measuring spectrometer to quantify trace gases in the atmosphere?

I am using a Pandora spectrometer and a MAX-DOAS spectrometer to quantify the amount of formaldehyde (HCHO) present in the troposphere and stratosphere in Fairbanks, Alaska. Both the spectrometers use ...
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1answer
72 views

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

The solar radiation is one of the important factors controlling the formation of $O_3$, and thereby impacting the levels of various secondary species in the atmosphere. However, in the campaign of ...
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1answer
15 views

Can the Air Mass Factor (AMF) be negative?

I am using a untraviolet-visible spectrometer to measure Vertical Column Densities (VCDs) of trace gases up to the stratosphere. It is physically impossible to have negative VCDs. I have observed some ...
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1answer
60 views

Does “Arctic Greening” mean an increase in the spatial extent of vegetation, an increase in particular types of vegetation, or both?

I am trying to study the impact of biogenic volatile organic compounds (BVOCs) on the atmospheric chemistry of the Arctic Region which has been said to be "greening", by taking HCHO as a proxy.
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50 views

Do NO2 and O3 titrate each other out in the atmosphere?

Here is a plot of the vertical column densities of NO2 and O3 from an ultraviolet-visible spectrometer in Fairbanks, Alaska. It is interesting to see that when NO2 dips, O3 rises, and vice versa. Also,...
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Quantitative principles to discriminate the photochemical activity in the atmosphere

Background In the area of atmospheric chemistry, many species have the primary origins and secondary formation pathway. For example, organic aerosols can be emitted directly from fuel combustion, ...
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40 views

The difficulties for the simulation of atmospheric metals

Atmospheric metals usually reside in aerosols with complex source origins. The concentrations distribution of metals especially for those with high toxicity (Pb, Cd, Ni, V) should be informative for ...
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How to analyze this data showing atomospheric CO2, CH4 and tempertures obtain from an ice sample?

Here is the chart: My questions are: Is the atmosphere in equilibrium over this record? how would I determine what the maximum and minimum values for each record is (approximation). Is there a ...
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2answers
87 views

A rough picture about the ground-level ammonia (NH3)

Ammonia is the only alkaline gas in the atmosphere. It is one of the key features to control the acidity of aerosols and the formation of ammonium salts. In the environment of $NH_3$-rich and $NH_3$-...
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2answers
89 views

Can I use diamonds as fossil fuel?

Aside from cultural implications (correct me if I'm wrong but artificial diamonds are not so hard to obtain, right?) diamonds are pure carbon and are more unstable than graphite. So, why not use ...
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1answer
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How did $\text{CO}_2$ originate on Earth before there was life?

To start life there has to be $\text{CO}_2$. $\text{Solar energy} + 6 {CO}_2 + 6 H_2O \longrightarrow C_6H_{12}O_{6} \text{ (sugars)} + 6 O_2$ $C_6H_{12}O_{6} + O_2 \longrightarrow H_2O + {CO}_2 + \...
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1answer
26 views

What's the difference between uptake and adsorption of gas into aerosols

In the area of atmospheric chemistry, I have learned that the heterogeneous oxidation of SO2 is one of the important pathways for sulfate formation. The reactions of SO2 oxidation in mineral, soot ...
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1answer
119 views

Why is the Earth's shadow blue?

After every sunset, once the sun is gone, I always enjoy seen the belt of venus rising in the other side, followed by the Earth's shadow. This is a picture I took (you will find better ones online). ...
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1answer
46 views

The influence of special emissions (possibly coal mining activity) on particulate matters

Based on multiple site sampling of airborne $PM_{2.5}$ and $PM_{10}$ , the elemental concentrations of the trace elements were analyzed. I have found out in the site near surface coal mining zone ...
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1answer
55 views

What controls the tendency of trace elements in different particle size fractions?

Trace element atmospheric particles are introduced from different sources, with both anthropogenic and natural origins. By analyzing the concentration levels of 18 elements in samples of $PM_{2.5}$ ...
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The factors should be considered to determine one specific pollutant originated from regional transportation?

Ideally, one pollutant (e.g. organic carbon, heavy metals, sulfate) should be the mixed result of local emissions and regional transportation. To quantify the contribution of local emissions is of ...
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1answer
42 views

What control the atmospheric lifetime of different metals in aerosols?

Background I'm analysing the metallic elements in $PM_{2.5}$ to identify their possible anthropogenic sources for the study area. A total of 19 metallic elements were investigated including dust-...
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2answers
43 views

calculation monocationic elements

How to calculate of the number of monocationic millimoles? If I have concentrations of: $SiO_2$, $TiO_2$, $K_2O$, $MgO$, $MnO$, $Na_2O$, etc. How can I get $Na^+$, $Mg^{2+}$, $Mn^{2+}$ ..? This is ...
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Is there a conceptual diurnal model for ozone profile?

So i know that there are diurnal patterns for virtual potential temperature that can be described conceptually (such as $\frac{\partial \theta_v}{\partial z}\approx 0$ in the mixed layer and $\frac{\...
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0answers
60 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
83 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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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
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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 ...
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1answer
76 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 ...
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1answer
60 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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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 ...
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1answer
54 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 ...
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57 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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33 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 ...
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1answer
317 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 ...
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2answers
69 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 ...
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2answers
115 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. ...
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1answer
55 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
1k 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
893 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 ...
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1answer
514 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.
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1answer
250 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 ...
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85 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 ...
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1answer
86 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 ...
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54 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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174 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 ...
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1answer
221 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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62 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 ...
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1answer
602 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 ...
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2answers
2k 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 ...
11
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1answer
149 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 ...
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1answer
887 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 ...
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2answers
210 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 / ...
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1answer
281 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)...