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Atmospheric Pollution - Science topic

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Questions related to Atmospheric Pollution
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Currently, it is possible to monitor air quality using chemistry transport models and calculated concentration data dissemination platforms. In a localized agglomeration of atmospheric pollutant measurement stations, is it possible to carry out a study of urban air pollution by using only the data from these models ?
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The following link is also very useful:
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How would you rate the environmental protection activities undertaken in your country? Are these actions sufficient?
Are activities undertaken in the field of environmental protection insufficient? If they are insufficient, what do you think should be done in terms of increasing environmental protection efforts?
The problem of environmental protection currently does not apply only to the reductions emitted by industry, automotive industry and developing urban agglomerations of environmental pollution. The problem of environmental protection is increasingly connected with greenhouse gas emissions and gradual increase of temperature at the Earth's surface and related climate changes, increasing scale and frequency of weather anomalies and increasingly occurring climatic cataclysms. It is necessary to develop renewable energy sources and ecological innovations in energy and other areas of green economy development. It is necessary to increase the dimension in sustainable economies as soon as possible in order to slow down the global warming process and reduce the scale of environmental pollution and to increase the scale of projects undertaken to rehabilitate a degraded environment.
Do you agree with my opinion on this matter?
In view of the above, I am asking you the following question:
How would you rate the environmental protection activities undertaken in your country?
Please reply
I invite you to the discussion
Best wishes
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It is often poor, and the environment is subjected to daily deterioration due to the large number of factories and other things that have developed at the present time
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Is the ongoing global warming process or the rivers flowing into the seas and oceans pollution are the main factors generating threats to the biodiversity of the oceans and ecosystems?
Are there any other factors resulting from the development of human civilization that generate threats to the biodiversity of the oceans and ecosystems?
Please reply
Best wishes
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Dear Anton Vrdoljak,
Thanks for your post and beautiful photos.
Greetings,
Dariusz Prokopowicz
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Hi there,
I'm currently monitoring air pollution in Grenada, West Indies and as part of my project I have identified four scenarios in which I would like to use a back-trajectory analysis (HYSPLIT) to determine where air parcels at breathing height are sourced from, to get a better understanding of what may be influencing air quality for people living in Grenada.The four scenarios I am interested in are: 1. During a Saharan dust event with COVID-19 government interventions implemented, 2. During a Saharan dust event with no COVID-19 government interventions implemented, 3. Not during a Saharan dust event with COVID-19 government interventions implemented, 4. Not during a Saharan dust event with no COVID-19 government interventions implemented. Is it possible to use HYSPLIT back-trajectories to determine where air parcels at around breathing height are sourced from to determine what is influencing the air quality of this particular location (Grenada) at particular dates and times that satisfy each scenario?
For example, I would expect that during scenarios 1 and 2 that back-trajectories would lead back to the Sahara/Sahel of the African continent, given the proper starting height for the back-trajectory.
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It seems that the COVID-19 has positive effects on plants and air purification.
I have a field observation that reduced emissions from factories reduced soot and dust on plant leaves, thus improving their growth and thus increasing oxygen releases.
I wish you good luck
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Ces derniers jours nous avons remarqué de bonnes choses sur le climat et l'environnement. Par exemple, on note une nette amélioration de la qualité de l'air. Une pause planétaire de deux mois a montré la diminution des émissions de gaz carbonique et de dioxyde d’azote (NO2). Sachant que la pollution atmosphérique a un effet important sur le climat.
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In recent days we have noticed good things about the climate and the environment. For example, there has been a marked improvement in air quality. A two-month global break has shown a reduction in carbon dioxide and nitrogen dioxide (NO2) emissions. Knowing that air pollution has a significant effect on the climate.
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How should one compare the NOx emissions (where the impact on nature and mankind is mostly local) and green house gase emissions (e.g. CO2) where the Impact is mostly global?
The question is of importance, if for instance a Technology is reducing the CO2 Emission but is increasing the NOx Emission - or vice versa.
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The direct greenhouse gases are carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). The indirect greenhouse gases are non-methane volatile organic compounds (NMVOCs), nitrogen oxides (NOx) comprised of nitrogen monoxide (NO) and nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO).
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I've calculated Direct Aerosol Radiative Forcing(DARF) values (W/m2) for Ahmedabad and Gandhinagar City, Gujarat, India using SBDART Model (AOD values as an input) at Top Of Atmosphere (TOA), Surface (Surf) and net Atmospheric Radiative Forcing(Atm).
Please let me know how to interpret these values and how to further analyse the data.
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Hi... Yash
Aerosol Direct Radiative Forcing (ADRF) depicts the scattering and absorption of solar radiation by aerosols. the positive values of ADRF indicate the warming and negative values indicate the cooling.
I hope that you have calculated ADRF using up and down radiative flux values. SBDART only provides up and down radiative fluxes later you have to calculate radiative forcing using those values. This method is already published by the many aerosol experts. You can refer to those publications.
Estimated TOA and SFC ADRF indicated the change in flux at TOA and SFC by aerosols. ADRF in the ATM indicates the change in flux within the atmosphere.
Further, you can more clearly associate these estimated radiative forcing to the climate by calculating heating rate. heating rate depicts the warming of the atmosphere. This can easily associate with regional or global climate change.
Herewith I have given you a very basic idea, but I will suggest you to read the related publication and their interpretation. This will give you more idea.
Hope this will help. Feel free to ask me, if you have anything
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Trees in urban system provide a variety of ecosystem services including biodiversity conservation, removal of atmospheric pollutants, oxygen generation, noise reduction, mitigation of urban heat island effect, microclimate regulation, stabilization of soil, groundwater recharge, prevention of soil erosion and carbon sequestration. The important roles played by green spaces are social, economic, cultural and environmental aspects of sustainable development. Urban green spaces can be a comprehensive tool for long term protection of environmental sustainability through improving the quality of life and air quality, increasing property value due to their amenity and aesthetic characteristics, and reducing the energy costs of cooling buildings.
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I think to answer the first part of your question we should consider different criteria such as urban policy, urban economics, urban climate, etc. Regarding the second part of your question, I think it would be important to consider the feature of urban green spaces like the cooling effect of urban green spaces, which has a significant role to improve the physical and psychological health of residents.
I have two studies in this case maybe that would be useful for you.
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Atmospheric chemistry is very complex science with various processes work in tandem. Here, we discuss only about chemical transformations by ruling out transport and deposition processes, in the atmosphere. There are many chemical mechanisms available to choose from and work with for the chemistry and air quality studies. People work with either one mechanism for specific problem or many mechanisms as part of "intercomparison of mechanisms". A lot of such studies have been carried out so far.
Despite being it complex, one has to have kinetic level understanding of the processes in the modeling. Here, I would like to know if the atmospheric chemistry modelers have that understanding already. If so, how did they develop that skill?
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Inventing of the artificial chemistry is definitely to be avoided if we want our models to have any relation to the real atmosphere. This problem was discussed by Heymann (2010): Lumping, testing, tuning: The invention of an artificial chemistry in atmospheric transport modeling (Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics)
The paper was published in the special issue dedicated to modeling and simulation in the atmospheric and climate sciences and the text is available on request in the RG system.
Considering the complexity of the problem it is indeed very wise to perform first the detailed kinetic studies (both theoretical and experimental) followed by the rational compression of the chemical mechanism. In this area I would like to suggest Sportisse (2000): Reduction of Chemical Kinetics in Air Pollution Modeling., J. Comp. Physics, Vol 164, issue 2, p 354–376
The reality of chemical modeling is that some atmospheric chemistry models still use the outdated lumping methods. It is indeed an excellent idea to revisit these problems.
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According to my knowledge of remote sensing the lidar requires insitu measurements and can be interfered with and biased by the climatic conditions of the study area, are there any alternatives to this methodology for the quantification of PM 2.5 and PM 10 and what is the best type of image to quantify these aerosols?
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Dear Mounsif,
Remote sensing has been widely used for environmental application such as for air quality and water quality studies. But the atmosphere affects satellite images of the Earth's surface in the solar spectrum. So, the signal observe by the satellite sensor was the sum of the effects from the ground and atmosphere.
As far as your question is concerned, of course we can monitor air quality by remote sensing satellite imagery. You would know of Aerosols monitoring with the MODIS, MISR, OMI, and VIIRS satellite instruments and various other Application of Satellite Data to Particulate, Smoke and Dust -Monitoring Satellite derived aerosol optical depth-PM 2.5 relationships. However, we have to acknowledge that there is certain uncertainty during the retrieval.
A large number of publications are available on this topic, especially to improve the correlation between satellite data (e.g. AOD) and ground-monitored levels (e.g. PM). They can be easily found online.
Regards,
Tejas
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There is a need of integrated assessment modelling for climate change impacts evaluation.
Intra-sector for agriculture (including rapid spatio-temporal changes in soil fertility, ground and surface water availability, cropping intensity hike for meeting food demand, rapid change in insects-pests dynamics).
Inter-sectoral (for agricultural impacts_- energy, health, socio-economic concerns, industrialization, atmospheric pollution, communication, etc.
Climate change on agriculture - well documented, mostly on point results & lack of regional validations
Existing Models deal with crop-weather interaction in solo, with boundary  conditions for other bio-physical and socio-economic aspects fixed, in most of the studies. 
Need to evolve IAM (Integrated assessment modelling) at this this stage
There should be some research group working on this aspect, or formation of a group to initiate these actions in near future
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Does anyone know how frequently sand storms and dust storms that arise from middle east or north africa travel to Pakistan and North India? I was wondering, in view of the already worsening air pollution levels in North India, events such as dust and sand storms reaching the subcontinent may exacerbate the situation. How rare or common are such sand and dust storms being carried from their place of origin (usually middle east and north africa) and intermix with fog or haze intensified by smoke or other atmospheric pollutants in another far off location? Has there been any similar, possible mixing of phenomena (dust storm and smog) reported/documented/studied anywhere around the globe at any time, preferably that was also caught by polar or geostationary satellites?
I was looking at a true-color or natural color satellite image acquired on 29th Oct. 2017 by the Visible Infrared Imaging Radiometer Suite (VIIRS) on board the joint NASA/NOAA Suomi-National Polar orbiting Partnership (S-NPP) satellite around early afternoon. I've attached a screenshot of the image as well as provided the full link to access the satellite imagery. These satellite images have been stitched together to create a global mosaic. Unlike MODIS, VIIRS do not show any data gaps (except sun glints!). I found this satellite image particularly compelling because it clearly shows the sand storm picking up over northern Saudi Arabia and moving around Iraq, Iran, Caspian Sea towards Afghanistan with the movement of wind. I also think the Earth's rotation from west to east has a role to play in the movement and direction of the wind laden with sand and dust. But it seems difficult to understand their dynamics. The smog over North India and parts of Pakistan can be differentiated from the sand storm over middle east in this satellite image. In North India this is the time of the year when there are intentional crop fires due to the traditional slash-and-burn agriculture practice.
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Dear RG Community, I have the need to estimate the PBL height for the area of Milan (Italy) in two years (2011, 2014) as 12-hours values more or less. These data will be necessary to run a model for the estimation of airborne pollutants, removed by vegetation.
Searching in the web I found this database
but I don't know how and if it is "easily" possible to calculate PBL from them. I will be very gratefull if some collegue can help me to better deepen the problem. Thanks in advance.
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Hi Valerio,
I am sure you must have figured out a solution by now (since you posted the question 2 years back). However, here is what I found useful for calculating PBLH using the sounding data from the above mentioned website. Observed Diurnal Cycle Climatology of Planetary Boundary Layer Height, Liu, Shuyan; Liang, Xin-Zhong, Journal of Climate, vol. 23, issue 21, pp. 5790-5809. The authors have used a FORTRAN code that they developed for calculating PBLH using the sounding data.
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Air pollutants like ozone, particulate matter, carbon monoxide, nitrogen oxide, sulfur dioxide, lead cause atmospheric pollution which regards to ozone depletion, GH effect, climate change and human health effects. If anyone say the main factors of air pollution beyond of industry, means of transportation, solid waste generation and urbanization.
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Vehicle Emissions
Vehicle emissions are another source of fossil fuel emissions and air pollution. Private transportation accounts for about 10 percent of your carbon footprint, or the amount of carbon dioxide your lifestyle and activities contribute to the atmosphere, reports Carbon Footprint Ltd.
Industry
Industry is a major contributor to air pollution. Industrial processes release pollutants such as nitrous oxide and hydrofluorocarbons into the air. Agricultural practices, livestock rearing and landfills also contribute to atmospheric methane concentrations. The overall effect is an increase in the global warming potential.
Deforestation
Deforestation affects the atmosphere in several ways. Forests act as sinks for carbon dioxide through a process called carbon sequestration. Trees store carbon dioxide in their plant tissue as they take in this gas to undergo food-making. In effect, this action removes carbon dioxide from the air. When forests are burned and destroyed, this storage area for carbon dioxide is removed, increasing the concentrations of atmospheric carbon dioxide.
Wood Fires
Wood fires cause air pollution by releasing particulate matter into the air. These particles can become lodged in your respiratory system, causing irritation to tissues. The particles can also aggravate existing health conditions such as asthma, warns the U.S. Environmental Protection Agency.
Smoking
You are still at risk of the dangers of smoking even if you are a nonsmoker. The University of Minnesota estimates that up to 90 percent of the American population is routinely exposed to secondhand smoke. Tobacco smoke contains 40 carcinogens, making it an especially lethal form of air pollution.
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Secondary aerosols are becoming a huge concern during pollution episodes esp. in cities. They can make up to 50% by mass of the total aerosol loading at a given time. While it is clear that some chemical species are only known to be produced by gaseous precursors rather than being directly emitted, how do observational scientists distinguish between primary and secondary aerosol species from their measurements, or do they?
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Dear Tabish and Janusz
Primary particles are directly emitted by processes such as biomass burning, incomplete combustion of fossil fuels, volcanic eruptions, and wind-driven or traffic-related suspension of road, soil, and mineral dust, sea salt. Also biological aerosols are important  and often ognored (plant fragments, microorganisms, pollen, etc.) and considered as primary aerosols. Secondary aerosols  are formed by gas-to-particle conversion in the atmosphere (new particle formation by nucleation and condensation of gaseous precursors). You can also have a mixture of both as biological micro-organisms can stick on SOA (mixture of primary and secondary aerosols). One kind of  hybrid is called polluen (pollutant + pollen) (see http://www.jle.com/fr/revues/ers/e-docs/synergie_entre_pollens_et_polluants_chimiques_de_l_air_les_risques_croises_130005/article.phtml). This mixture is rarely considered.
Concerning oxidized nitrogen only NO (nitrogen monoxide) and N20 (nitrous oxide) are directly emitted in the atmosphere. Particles of NO3-  is formed through reactions in the atmosphere and is therefore a secondary aerosol.
Concerning reduced nitrogen, only NH3 is produced and NH4+ is obtained through oxidation and therefore is a secondary aerosol also. Same for sulfates.
Sulfate, nitrate, and ammonium are important inorganic constituents of urban aerosol particle and account for 30-70% of PM2.5. Through filter packs , it is  possible to identify these species. However, there are numerous challenges ( see
In fact, accurate determination of the chemical composition of air particulate matter is a formidable analytical task.  (see Poesch p 7523 near the bottom, i.e. refered by Janusz above )
So the bottom line is a knowledge of which species is primary and which is secondary is helpful but not sufficient given the complexity of the problem (contamination by biological particles, formation of hybrid, etc.). Actual technique cannot resolve everything.
My hope in the future is that a particularly challenging application of aerosol mass spectrometry develops, i.e. the one with high relevance for public health and security is the identification of biological particles and pathogens (bacteria, viruses, spores, etc.). i.e primary and secondary mixed aerosols.
Hope it helps
Alain
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I would like to know that by comparing the periodograms for a pollutant concentration and its sources, whether it can be deduced that seasonality of the source is causing the seasonality of the pollutant? 
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Well, plotting data of each pollutant concentration with time, and plotting the concentration of same source pollutant in the same time can be shown best correlation.
good day
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I have observed traffic volume and an air pollutant over a time period of 12hrs during daytime for 3 consecutive days. Is it possible to check seasonality and trends, detrend and fit a Box-Jenkins model for both data?
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Hello, I think yes, because any continuous time series can be discretised and analyzed as a discrete time series. But you must look at the long of your time series because of you need to apply statistical tools among others tools. Also you should keep in ind if the time series is linear or nonlinear. For instance, Pm2.5 and PM10 concentrations are nonlinear and you should work with carefully!
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I am trying to derive a relation with traffic volume and pollutant concentration observed during daytime for a week. It is seen that from time series of both data, the traffic volume seems to have an inverse relationship with pollutant concentration. I believe due to favourable meteorological conditions at day time, concentration is getting dispersed although the emission increases. Is it possible to remove the effect of meteorological parameters by deseasonalizing the pollutant data, so that the underlying trend between traffic and pollutant is more clear?
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To really understand your correlation, you need to allow for the vertical turbulent structure of the boundary layer, which maximises in most circumstances through daylight hours because of solar heating. At night, radiative cooling tends to lower the height of the boundary layer, leaving less air to dilute the traffic emissions. One way to do it statistically is to characterise all visible cycles and subtract them from the data: the diurnal weekly and seasonal cycles of winds, temperature etc which are meteorological, and of the traffic flow which is anthropogenic. The results may be useful statistically, but need to be viewed with caution from the point of view of scientific understanding.
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particulate matter
air pollution
model 
correlation
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Your question leaves me with several question marks. Are you looking into dispersion of airborne particles (transport equations with particles' settling speed)? Or are you looking into erosion by atmospheric wind?
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I want to model the dispersion of different air pollutants (PM10, PM2.5, NOX, SOX) of individual freight vehicles on link level (high used roads). When looking for dispersion functions, I ran always into these kind of formula (http://www.eea.europa.eu/publications/TEC11a/page014.html). If I understand them well, those are not considering; 1. the differences between various pollutants, 2. dispersion generated by the flow of subsequent vehicles, 3. the decrease in concentration throughout time. Is it possible to consider those three too? With which formulas? I thank you in advance.
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There are virtually hundreds of different dispersion models around. If you look at the top of the page, it says: "This annex documents simple models for first estimation or screening." And that's what it is.
For instance, Model C is applicable on roads with complete obstruction by buildings on both sides of the road. Model D does not consider any buildings. A real dispersion situation will be somewhere in between. And the dominant wind direction will not be in a 90° angle to the road and... The selection of a suitable model depends on the situation you want to analyse. And on the level of detail you want to (or have to) achieve.
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Greetings,
I'm wading through Jacobson (2014), learning that the net radiative forcing from biomass burning emissions is a complex story. Does anyone know of any work that's been done to characterize the suite of products (trace gases, black/brown carbon etc.) emitted from wildland biomass burning according to fire intensity, flaming/smoldering phase, fuel component, moisture content, fuelbed/ecosystem type?
I'm imagining that while chemical soup(s) have been measured in plumes (via, say, instrumented aircraft) from wildland fires and reported in literature, there's not much to relate the chemical profiles back to fuel bed/combustion conditions etc.
thanks for any pointers
K. Scott
*Jacobson, M. Z. (2014), Effects of biomass burning on climate, accounting for heat and moisture fluxes, black and brown carbon, and cloud absorption effects, J. Geophys. Res. Atmos., 119, 8980–9002, doi:10.1002/2014JD021861.
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I have gathered a list of Papers on GHG emissions from bioenergy related land-use, which is somewhat related to your question: https://agwobserver.wordpress.com/2014/03/10/papers-on-ghg-emissions-from-bioenergy-related-land-use/
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During a field study, I found that PM10 level was as high as 234 μg/m3 at a location while at the same location PM2.5 was just 23 μg/m3. Is it possible to have that much difference between these two parameters? The sampling location was a residential area and is close to a haul road.
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Rishu:
It is not surprising to obtain such significant difference in PM10 and PM2.5 levels. The haul road (unpaved surface)  is likely to generate larger particle sizes that may fall within PM10 range. The 23 ug/m3 PM2.5 might probably come from vehicle/haul truck exhaust and very fine airborne dust that are 2.5 microns and below. You are more than likely to obtain higher concentrations than observed for PM10 if you do Total Suspended Particulate (TSP) measurements. Airborne dust emitted from haul roads are likely to have larger sizes than PM10. So in effect, you will observe the order of concentrations of particulates (descending order) as TSP, PM10, PM2.5 with significant differences among them.
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Pollutant particle transportation is usually slower than water itself while they look like travel together. However nutrient transportation involves too many biological interactions and sediment deposition so we often need to resort to experimental techniques. 
My question is what is the theoretical relationship between this two velocities (celerity for hydrology and velocity for nutrient) from the point view of hydrodynamics without involving experiments. Any useful equations or references? Thanks a lot!!
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Thank all of your ideas! I also found an interesting literature on this if anyone would be interested to read: 
McDonnell, J. J., & Beven, K. (2014). Debates—The future of hydrological sciences: A (common) path forward? A call to action aimed at understanding velocities, celerities and residence time distributions of the headwater hydrograph. Water Resources Research, 50(6), 5342-5350.
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Just a rough estimate. My idea was. First calculating Mass flow rate = air flow rate through the column / the molar volume of air at normal temperature * Pollutant concentration ppm * Molecular weight pollutant. Result will be g/H2S/min
Than I wanted to calculate Carbon bed lifetime = Media capacity for H2S * Media volume/ Mass flow rate. This shoud give me idea about capacity of my column exactly for H2S g. 
Than just calculation of time. But I don´t know how, results are nonsense. :(
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Dear Michal
The Dr  Sébastien Vaesen's answer is completely perfect 
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Hi
Air pollution in my country represented as big problem..., how can l study this problem by using mathematic model?
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Dear Nada,
Please do your homework before asking for help from your colleagues. A quick search on the Web for "mathematical modeling of air pollution" led to over 1,200,000 results, many of which are papers you can access freely.
If you are overwhelmed by the number of sources available, then start from the IPCC 5th assessment report, available from https://www.ipcc.ch/report/ar5/. And if you'd like to focus on an open source journal which published a number of papers on that topic, then look first at Atmospheric Chemistry and Physics (ACP), which is available from http://www.atmospheric-chemistry-and-physics.net.
Even books and book chapters that review this question are downloadable from the Internet: see http://envirocomp.org/books/chapters/2aap.pdf and http://www.eolss.net/sample-chapters/c02/E6-03B-04-04.pdf, for instance.
Regards, Michel.
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Total sulfate is originated from sea salt, dust, and produced by oxidation of SO2 in the atmosphere.
I would like to know how to calculate the portions of sea-salt sulfate and mineral dust sulfate by using sodium and calcium or magnesium, respectively, as tracers.
in another way, how can I estimate the portion of  non-sea salt sulfate?
thanks
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I want to know what types of satellite imagery used and what algorithms should be used to know the concentration levels in cities of some air pollutants.
Thanks in advance
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I consider to relate the air pollution to a visible parameter as the Bergerhoff model to measure dustfall, but there are another methods to make people aware of it.
I want to find methods, mainly those of easy comprehension to the people in my town and could be used to make some practical recomendations to them.
There are rough demonstrations like a plastic container with water where particles fall down and float over the fluid surface, but that method can not demonstrate some of pollutans and couldn't be used to measure and describes them and that is very important.
Please help me to find those methods and if you know about handmade methods that's better.
Greetings
Jose Julio Cerro Rodríguez
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Questioner
We provide you answers; thus (please) make an effort to comment!
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When we talk about carbon Trading.Emissions Trading Scheme (ETS) of the European Union,or any other organisation why only Carbon emission has been pointed out not other harmfull gases
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In carbon trading mechanisms, the global warming impact of other gases (e.g. methane and nitrous oxide) are expressed in terms of CO2 equivalents.
The conversion factors are: 25 for CH4 and 298 for N2O (over 100-year time span).
This means that the impact of 1 kg of CH4 is similar to 25 kg CO2 equivalents and the impact of 1 kg of N2O is similar to 298 kg of CO2 equivalents over 100-year time span.
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I need the measure to build six Bergerhoff Model's structures like length, width and height of each part of it and parameters to use it to measure the atmospheric dustfall.
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Hans Puxbaum is right, the relation with health hazards is weak, at least effects by inhalation. Although some indirect effects can be expected, for instance by uptake of deposited metals in vegetables, or by ingestion of polluted soil by children. But than again, this effect is uncertain.
If you can read German (perhaps with a bit of help of Google translate?), some more information is available at the sites of LANUV, the State Agency for Nature, Environment and Consumer Protection of North Rhine-Westphalia in Germany. Here are some links (Staubniederschlag is dust depostion):
http://www.lanuv.nrw.de/umwelt/luft/immissionen/staubniederschlag/ with background information, a short description of the Bergerhoff method, German norms for 5 metals and buttons to Messnetz( measurement network):
with indications of possible applications of the method like Hans Puxbaum meant,
and Messergebnisse (Measurement results):
with annual and trend publications on dust deposition and its components like Pb, Cd, As, Ni, Tl, Hg, and dioxins, furanes and PCB's.
Hope this helps!
Greetings,
Marcel Severijnen
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Hi,
I was looking for some key articles for example well cited ones on the primary determinants of outside or ambient air pollution of cities worldwide. Are you aware of any such articles?
Any help will be much appreciated.
Thank you.
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We have the bags with various length and diameters with different compress air cleaning pressures and consumption.
I would like to know the basic rules for designing the compress air pressure and consumption with regards to bag length and air pressure and types of  jet pulse diaphragm valves.
Kind Regards
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An industrial thumb rule is 8 - 12 liters/m2 FAD of Bag Area
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Which oxidizer would you choose when you want to degrade VOC (Volatile Organic Compounds)?
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Air is the best oxidant without any doubt. 
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SIA (secondary inorganic aerosols) like SO4, NO3, NH4 etc. have been found to contribute significantly to PM2.5 mass in urban areas. Is there a general rule that they are predominantly a result of secondary formation from their gaseous precursors (SO2, NO2, NH3 etc)? Or are they also primarily emitted? Can we make some generalizations based on current state of knowledge?
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With respect to your comments particularly about sulfate, another important source is sea salt, in which the concentration of this ion is usually around 10%, according to the SPECIATE database (Profile Number: 4310110). It is also well known that this ion is already present in seawater, due to the oxidation of Dimethyl Sulfide (DMS) emitted by phytoplankton, so it is definitely emitted as a primary aerosol, in this case.
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the impact of commercial kitchens in the surrounding environment, by vapors , odor . or smoke and if there are nay  methods of reducing such pollution  
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Is it possible to reduce the private ownership of cars by promoting the use of virtual cars summoned by cellphone apps? What public policy recommendations have been made worldwide and what government incentives have been offered to achieve this?
Background information: The use of computer apps to request taxi services has created a new industry, with companies like Uber and Ola growing at an impressive rates. However, Societies have not recognized that this new form of public services can contribute a lot to reduction of atmospheric pollution and traffic jams on the streets. It can also contribute to job creation. Visit
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There has been rapid growth in the use of apps to get access to autorickshaws in Bangalore. I suspect that this is happening in other big cities of India in parallel. A app-based-cabs company has been including autorickshaws in its menu for more than a year. Their pricing technique has now proved very successful. We pay a "convenience charge" of Rs 10 (equivalent to about 15 US cents) over the meter indication. The driver seems to keep Rs 5 and the app company takes the other 5. I find it is very easy to get autos anytime I want in Bangalore to go anywhere.  Technology and transparency enabled by it have achieved what policing has failed to achieve over decades. 
Another convenience: I am able to pay in cash, or out of a digital wallet run by the company. As a result, I don't have to worry about the driver saying he has no change.
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The contaminants in agriculture are attracting more and more attention now a days. The contribution of ammunition burning is not comprehensively addressed. 
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The question is a very deep one. As at now I don't think anyone has carried out a research on that, but i do know that most of the freshwater systems in the world are getting polluted day in day out. With freshwater constituting less than 3% of the water in the world and more than 1% of that existing in solid (ice) form, burning of ammunition will certainly have a toll on freshwater since that is what farmers depend on in agriculture. Burning of ammunition leaves traces of poisonous and radioactive elements such as uranium  in the earth crust. Ultimately, when it rains, two negative things happen. There is streamflow into rivers, lakes and other water bodies on which agriculturists depend on for irrigation purposes. This deteriorates the soil structure and affects the growth of plants. Secondly, some of these elements are leached and this can also affect groundwater. However, this is less serious as sometimes groundwater is too deep to be reached.
The Middle East has the highest concentration of wars in the world, therefore most of the water bodies in the countries that engage in wars have their freshwater systems degraded. Apart from that, livestock are also destroyed. All this have a toll on agriculture and since burning of ammunition is frequent in such places, the contamination is also drastic.
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In order to identify the potential pollution sources in my receptor site, I investigated the air mass back trajectory using HYSPLIT model. How can I perform in selecting the arriving altitude of back trajectories ? This altitude should be above or below than mixing layer height?
thanks
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We tend to use heights of between 200-500m for our back trajectory analyses. These elevations are well within the convective boundary layer during the day, but above the nocturnal boundary layer under most conditions. This means that, if you are trying to look at source/fetch regions corresponding to measurements made near the surface, then relating back trajectories to observations made between about 10am and 5pm each day (when mixing is fairly strong, and near surface measurements are representative of most of the CBL) is OK. At night, however, under all but the most windy and well mixed of conditions, any near surface measurements you make are likely to be partially (or completely) decoupled from what is happening aloft in the residual layer (200-500m). Under these situations, your measurements will have a fairly restricted "footprint" and the trajectories you calculate may not be related to this fetch at all (particularly in regions of uneven terrain where nocturnal drainage flows may occur under stable conditions). Cheers, Scott.
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I am working in the production of the above agricultural products but read some item that potash has a negative effects on beneficial bacteria in the soil. I would like to know if it has the same effects on this bacteria too.
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Yes
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Hello,
I guess we have all heard about the ongoing tragic and worsening situation in Greece since 2008 for a large fraction of the population there and for refugees from Europe and elsewhere who ended up in Greece.
I am no socio-economic or political  expert but I gather that the number of people living in  precarity has soared there. I have certainly met benevolent social workers  who shared stories of despair that are hard to forget.
Greece is afflicted by a range of natural hazards and risks of disasters. It has a recurrent and documented history of such disasters.
I am wondering to what extent it is still possible for Greek scientists and/or the international community to suitably anticipate and monitor for those potential disasters and to suitably prepare for a disaster response, considering the ongoing and arguably worsening (?) situation in Greece ?
I am thinking about large forest fires (and eg. resulting biodiversity loss and atmospheric pollution), severe thunderstorms, land erosion, flash floods and mud flows on the one hand, and of tectonic earthquake and volcanic eruption hazards that may also lead to a tsunami risk in the Mediterranean on the other hand.
With the situation in Greece, aren't the vulnerabilities and the risks of impacts from such potential disasters much greater in Greece, and for some of these hazards for the European-Mediterranean regions ?
Has anyone studied how vulnerability of the Greece population to such eventualities may have increased since 2008 ?
Has anyone studied how the risks themselves for a given disaster scenario may have increased considering increased vulnerabilities and other changes in the structure of the Greece socio-politico-economic systems ?
Tectonic earthquakes from the Aegean arc submarine faults in Greece could trigger a tsunami affecting the Mediterranean region.
Can the adequate monitoring and disaster preparedness efforts still be pursued at the present time ?
And if not, what may be the wide-ranging impacts ?
The unmonitored active shallow-marine Kolumbos Bank Volcano (6km to NE of Santorini volcano) erupted explosively in 1650 AD. If it erupts again in a similar way, what may be the risk of an impact for international air traffic similar to that which related to the Eyjafjallajokull 2010 eruptions ?
What may be the tsunami risks in the Mediterranean  if the Kolumbos Bank volcano erupted explosively again ?
So to sum up, I am wondering if socio-economic-political changes in Greece since 2008 have affected vulnerability, resilience and risks for a diversity of disaster scenarios ? And also who may have studied aspects of this ?
I am also wondering to what extent scientists in Greece and elsewhere can continue to adequately monitor for, anticipate, research, sensitize for, , and generally prepare for such disasters occurring in Greece ?
And if it is the case that  the Greek scientists have difficulties continuing their work (?), to what extent the European Commission and international negociators on debt alleviation in Greece may have taken such considerations into account ?
Is this not the sort of situation making the ground much more fertile for much-enhanced impacts of geo-disasters ? Including for some that may affect much of Europe or the  Mediterranean Countries ?
Anyhow, a whole series of inter-related questions there.
I am wondering what colleagues think of all this and if some of you may have elements of answer to some of these questions ?
Many thanks in advance for any insights.
With best wishes and kindest regards,
Gerald
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Hello Gerard,
 In your extensive analysis you did not include the fact that the Greek population is well educated and aware of the natural dangers that hit all too common for millennia. Although the country is short of money, many research projects are funded from EE and elsewhere, so there is not a big increase of risks since 2008.  You see some of the projects mentioned above.
For example, the Greek people were well aware of tsunamis before Dec. 2004, unlike most of the rest of the world. I think Greek people are better prepared than those in Canada by comparison. In the last 10 years or so the federal funding for anything to do with the environment including research at universities in Canada has been severely CUT to avoid people get the facts on weather, natural disasters, etc. The reason is the government has been extremely pro-fossil fuel with a “forget the environment” attitude (also was the only country to officially return its signature from the Kyoto Protocol).  The result is a big problem for preparedness in a developed country and a worry for those trying to educate the public/schools, etc
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I have one year long time series of CO2, CO and CH4 over an urban city. I want to remove their background for seeing the actual variability from their local emissions. What is the procedure for calculating the background mixing ratios of these gases on daily and monthly basis?
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Dear Naveen,
Please go through the attached research article, may be helpful to you.
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I am trying to analyze some filters outside from the country, but I  do not know how I may send this samples without controlling the temperature. Does anyone know how to send samples that must be at a temperature below zero? at least -1C? 
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 Dear Dayana, please look here (par 5.3).
Cheers Valerio
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Dear all. There is a queatsion about aerosol bothered me. In the CAM4.0 and the previous version of CAM, the aerosols are prescribed, meaning that the model doesn't include the interaction between aerosol and cloud, and the aerosol chemsitry. IPCC AR5 reported that the radiative focing of the aerosol-cloud interactions is larger than the radiative forcing of aersol-radiative interactions. So, in the CAM4.0 and the previous version of CAM, whether the radiative forcing of aerosols will be underestimated? And in this situation, how does the the model represent the climate change well?
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If  CAM model simulations use prescribed aerosol data, it means that these simulations do not consider the impact of atmosphere on aerosol, but include the impact of aerosol on atmosphere (cloud and radiation).    Note that the prescribed aerosol data used in CAM model considers the impact of atmosphere on aerosol.     Therefore, it's hard to say the radiative forcing of aerosols is underestimated because the aerosols are prescribed in the model. 
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Dear all, 
I am struggling to calculate the specie specific uncertainty for Polycyclic Aromatic Hydrocarbons in Positive Matrix Factorization version 5. I was reading the guide however, could not understand how to calculate uncertainty. Below is the paragraph given in PMF guide. 
"The equation-based uncertainty file provides species-specific parameters that EPA PMF 5.0 uses to calculate uncertainties for each sample. This file should have one delimited row of species, with species names (Table). The next row should be species-specific method detection limit (MDL) followed by the row of uncertainty (species-specific). Zeroes and negatives are not permitted for either the detection limit or the percent uncertainty. If the concentration is less than or equal to the MDL provided, the uncertainty (Unc) is calculated using a fixed fraction of the MDL "
Table
Unc.      Aluminium   Ammonium   Arsenic    Barium
     2        0.00419         0.0125       0.00098   0.0068    
    10           10                  10             10            10
In above mentioned Table decimal values are MDL value of given species but I don't know that what is "10" and "2", if 10 is uncertainty then how can we calculate it?
Secondly I have 52 weeks samples (1 sample per week and 17 studied species). My question is whether I have to calculate Uncertainty of all species for all sample or I can use only one uncertainty values for all samples.   
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Hi Waqar,
The uncertainties for each PAH species should be determined as part of your analytical method. Presumably you have quantified your PAHs using some GC/MS variant so there will be plenty of literature out there about how different groups have calculated uncertainty. The USEPA would also likely have a guide for quantifying uncertainty for the analysis of PAHs because there is a standard method. Your analytical method should also produce MDLs which can be used to calculate uncertainties for those samples below the MDL. I would highly recommend reading: 
Polissar, A.V., Hopke, P.K., Paatero, P., Malm, W.C., Sisler, J.F., 1998. Atmospheric aerosol over Alaska: 2. Elemental composition and sources. Journal of Geophysical Research: Atmospheres (1984–2012) 103, 19045–19057 and Kara, M., Hopke, P.K., Dumanoglu, Y., Altiok, H., Elbir, T., Odabasi, M., Bayram, A., 2015. Characterization of PM Using Multiple Site Data in a Heavily Industrialized Region of Turkey. Aerosol and Air Quality Research 15, 11–27. doi:10.4209/aaqr.2014.02.0039
which should give you an idea how to treat your data. To answer your other question, depending on how your uncertainty is calculated, you may have one value for each PAH, or you may have a different value for each PAH in each sample.
A few things appear a bit problematic with your wider study. First, 52 samples is quite low for a source apportionment study. Typically you would want more than 100 samples. Obviously sampling for longer may not be possible all the time, but the small number of samples could cause problems. More concerning for me is your attempt to apportion PAHs. I know in the literature this is widely reported, but care should be taken before you embark on this. I recommend reading: 
Galarneau, E. 2008. Review: source specificity and atmospheric processing of airborne PAHs: implications for source apportionment. Atmospheric Environment, 42: 8139-8149.
This paper highlights a number of problems with trying to apportion PAHs, most notable of which is that PAHs do not satisfy the most basic "rules" of receptor modelling. The arguments against trying to apportion PAHs are well-presented in the paper and may convince you to try using your data another way.
I hope this information helps and good luck with your work.
Travis
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My feed stream consist of 2% CO and remaining N2 with the total feed rate of 100 cc/min. I am using a Ni-CeO2 system. Ni is in reduced form. Kindly let me know how I can calculate equilibrium conversion of CO in the temperature range of 250 to 450 degree C. thanks in advance.
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Please explain your question a little more in depth.  You will have water gas shift, methanation and possibly some  higher HC chains formed, Boudouard reaction - all of which can be equilibrium limited depending and then one may have oxidation by CeO2 which will be nearly irreversible in a reductive atmosphere.  Thus to identify the CO conversion, one needs to have some water to produce the hydrogen.  In the absence of hydrogen, all you may be having is the CO2 formation by oxidation.
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I have read lot of lit. with ref. to biological indicators and preliminary analysis shows that algae are the best indicators. However, there are various groups of organisms which show varied reponses to pollution. The question is how to judge the capability of particular group as indicator. Also why to use use biological indicators when there are sophisticated sensors available. 
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Any highly sensitive species or highly non sensitive species to the toxicants may be use as bio indicator species. However, Bioindicator species must have fulfil the following characteristics features :
1. Easy to rare under lab. condition.
2. Short life span
3. Repeated generation
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I am getting single peak (12:00-3:00pm) for Aecetylene and propene in the diurnal plot.
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Acetylene and isopropene have been mostly reported as emission products from traffic with higher levels around noon, or at times with corresponding higher traffic volumes. Check out some articles of Agnes Borbon, http://www.lisa.univ-paris12.fr/fr/component/comprofiler/userprofile/aborbon or via researchgate. 
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Presupposition:
(1) not consider the interannual variability (IAV) of ENSO, IPO that are strongly correlated to the IAV of global mean surface temperature (GMST).
(2) Rising atmospheric CO2 concentration contributes to the increase of GMST.
Information:
(1) Katharine & Ken (2014): Maximum warming occurs about one decade after a carbon dioxide emission
(2) CDIAC, Global Carbon Budget 2014: CO2 emission rate increased by +1%/yr during 1990-1999, by +3.3%/yr during 2000-2009. It is triple rate.
Combined all these information (Presupposition+Information), can wen predict that the trend of GMST is positive during the 2010s, and may have a acceleration rate?
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Hello
There is no physical reason to say that 2015 will be warmer than 2014 since the interannual variability of global mean temperature is only weakly constrained by the long term warming due to anthropogenic forcing, which is a "slow" change when viewed from this time scale. In 2015, if ENSO switches to a cold event (but neutral conditions is more probable -see IRI forecasts-) and solar constant still decreases till the end of the current cycle 24, we have at least two sources of transient cooling for 2015 vs 2014 -and it is difficult to predict for other possible sources of internal variability-. The switch to cold ENSO could easily provide a -0.1°C signal in global mean temperatures (and solar constant decrease would add few extra hundredths at maximum). So even if all other conditions are constant, this could cool 2015 vs 2014 but it remains of course that it won't change the warming signal related to greenhouse gases increases.  
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I'm doing some research on this.
I will appreciate your help.
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The Government of Alberta site listed at the top of the first responses is a good one. I have worked with researchers in this group on poultry barn environments. We looked at respiratory disease incidence as it related to the dust composition of the barn, and litter treatments to control barn dust. I did a lot of the early microscopy work to characterize the dust in various barn environments.  I was working with John Feddes, who joined this group after he retired from the University of Alberta. I recommend looking up some of his work to get you started. They have also looked at worker health and dust from farm-types other than poultry. 
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Which one is better to remove SOx and NOx without adsorbed CO2 ? Zeolite or Activatexd carbon?
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No, that is not what I said.  BaO is commonly used as an adsorbent within commercially avaialble source emission control systems (e.g., NOx adsorption catalysts, often as Pt-Rh-BaO-Al2O3) that operate primarily under net oxidizing conditions.  NOx and SOx are selectively adsorbed under net oxidizing conditions and released under net reducing, high temperature conditions.  With proper sizing, storage of NOx and SOx can be >99% until adsorption sites become saturated.  H2O and CO2 are also a components of the gas streams that these systems are used with but adsorption strength is much higher for SO2 and NO2.  CO2 is adsorbed but, depending on the temperature, the carbonates formed on BaO are relatively unstable.  At about 200C and above, NO2 and SO2 rapidly displace carbonate and form stable barium nitrate and barium sulfate and CO2 is released.  Emissions control systems with BaO NOx storage are mass produced in the U.S. as part of the NOx emissions control systems on small to medium-sized diesel trucks.
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I need to compare results of running an air dispersion software at different scenarios (varying in the amount of the dispersed material) for 6 specific geographical locations. Which statistical significance test is suitable for comparing results of different scenarios (concentrations at these 6 locations): t-test (regular) or paired t-test?  
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Hi Dmitry,
To me it seems that you want to compare results that have some degree of dependence, using the same model and emissions for each run. In that case I would suggest to use the paired t-test.
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I want to derive correlation between PM 2.5, PM 10, TSP with MODIS derived AOD. In PM 2.5 , PM10 , TSP which one correlates better with AOD?
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The correlation between aerosols at the surface and the total column AOD is highly variable over time and space. It is relatively good for some areas and extremely weak for others. The main thing is to consider is the fraction of the total AOD that is located in the mixing layer, i.e. close to the ground. For background arid conditions and low AOD, the correlation is very weak, so you should not use it.
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I have been performing EC-OC analysis, using the sunset lab monitor (model 4), on atmospheric aerosols collected every 2 hours. However, in all of my samples I observe that the EC_OC split occurs before the introduction of oxygen (pre-oxygen issue) and the OCpeak1 is constantly higher than the reported thermal OC. This issue occurs for both PM2.5 and Coarse PM samples. I have tried several different temperature protocols (e.g. rtquartz, NIOSH5040, NIOSH870), but the pre-oxygen split still exists. I was wondering if anyone else has had the same issue? If so, how can this be solved? Also I want to know whether the values reported by the instrument are reliable when the pre-oxygen split occurs or not?
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The catalytic effect of metals was already the reason to use manganese in  two step oxidation procedure decades ago
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Any comments are welcome
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Have a look at the BS EN 14385 standard. Normally quartz filters require digestion in HF (hydrofluoric acid) as well as nitric - be vey careful with HF, check the MSDS!
Do an inital digestion in 3 ml HNO3 + 2 ml HF at 200C, minimum power 800W for at least 15 minutes. Then remove the vessel from the microwave and allow to cool, then carefuly open the vessel and add 20 ml deionised water and 20 ml boric acid (5% mass content). Replace the vessel in the microwave and heat again for 10 minutes at 200C.
After this, allow to cool and transfer to a flask etc for analysis.
Be very careful with the HF, check all safety information first before using any!
Make sure you have antidote gel to hand in the lab.
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What are the steps for using a Radiello passive sampler for analysing BTEX in outdoor air?
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Make sure the samplers are not directly exposed to sun, rain or to very strong wind. Make moreover sure that you record the average temperature during the period the samplers are exposed as you might have to correct the uptake rates in case the temperature is very different from 25C.
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Health risks caused by short term exposure to ultrafine particles generated by residential wood combustion: A case study of Temuco, Chile http://www.sciencedirect.com/science/article/pii/S0160412014000221
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Hello Luis, I believe we have met once. I think this is a very good question. EPA has been considering this for many years now. I am uncertain about the direction they will go. The strongest evidence for a health effect appears to come from the toxicology literature. However, EPA makes its decisions based on a wider range of evidence, including the epidemiological literature. We know that such epidemiological data is challenging to collect for ultrafines since their concentrations are much more variable in time and space than fine particulates (PM2.5). Such monitoring networks for ultrafines are simply not well established in the United States, which means that the epidemiological studies necessary to support an ultrafine PM standard are quite limited and would need to come from other parts of the world, particularly the UK or other countries in continental Europe. Another fact that is hard to dismiss is the recent review of the evidence of health effects of ultrafine particles from the Health Effects Institute. This came to a fairly weak conclusion and argued that more evidence on ultrafine particles is needed. It emphasized the need for epidemiological evidence, as I have highlighted here. You might consider reading through the HEI review if you have not already. This is available on their website at http://pubs.healtheffects.org/view.php?id=394. I hope this answer is helpful to you.
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In the city where I am doing sampling, it rains 6 months a year. So I really need help.
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It’s very important to carry out sampling in that condition because it’s representative of local climate. Where I live it rains all year, but not continuously. Always you can sample. All depends of what you are looking for, in others words, the purpose of monitoring. What, when and how to sample is matter of your monitoring program. The program between other things, depends on what pollutants you want to measure (as in before answers have been told), which sources you are evaluating, which sampling devices you have, and the frequencies and duration of rain. The design of a monitoring program involves many aspects and it should respond to the features of each situation. Based on my professional experience, I can tell you that it’s essential to sample gases from open biogenic sources under rain event. Rain showers or long rains produce layer mixing in these sources and consequently, large emission of gases that are before trapped in bottom layers, emissions as results of pH change and from other processes. Then, gas emission and outdoor concentrations can reach very high values. Without more details about your need and situation is very difficult to help you.
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Chemicals used in conventional agriculture systems pollute both the soil and the atmosphere and also jeopardize the health of both farm workers and consumers.The AM association has received attention as part of an increasingly popular paradigm that considers active and diverse soil biological community as essential for increasing the sustainability of agricultural systems . As suggested by Bethlenfalvay and Lindermann (1992), “The role of AMF may be critical if agriculture is to return to the state where luxury levels of farm inputs of fertilizers, pesticides and or chemicals are decreased to levels that are still economical, yet do not pollute the environment or pose health risk to consumers or handlers”.
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The mycorrhizal inoculum propagation is implemented using sterile soil, in which a grass is sown, such as B. decumbens like a trap crops. B. decumbes is good for Glomus and Scutellospora. After the plant is established, is subjected to drought period with occasional watering to stimulate sporulation. From these trap crops AM, the spore count is done to check the quality.
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Boundary layer height for inter-comparison of atmospheric trace gas measurements.
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PBL height can be derived from satellite GPS RO data. Some papers I have come across on the subject are listed below. However I have no specific information about where this data can be obtained.
von Engeln, A., J. Teixeira, J. Wickert, and S. A. Buehler (2005), Using
CHAMP radio occultation data to determine the top altitude of the planetary boundary layer, Geophys. Res. Lett., 32, L06815, doi:10.1029/2004GL022168
Sokolovskiy, S., Y.-H. Kuo, C. Rocken, W. S. Schreiner, D. Hunt, and R. A.
Anthes (2006), Monitoring the atmospheric boundary layer by GPS radio
occultation signals recorded in the open-loop mode, Geophys. Res. Lett.,
33, L12813, doi:10.1029/2006GL025955.
Sokolovskiy, S., C. Rocken, D. H. Lenschow, Y.-H. Kuo, R. A. Anthes,
W. S. Schreiner, and D. C. Hunt (2007), Observing the moist troposphere
with radio occultation signals from COSMIC, Geophys. Res. Lett., 34,
L18802, doi:10.1029/2007GL030458
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Gaussian atmospheric dispersion models: open source software
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Hello, here is what you are looking for: http://cerea.enpc.fr/polyphemus/applications.html
Polyphemus is an open source air quality modeling platform, including Gaussian plume and puff models.
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We want to collect PAH samples on 47mm circular filters instead of 8x10 inch sheet filters with a fine particulate sampler having flow rate 1m3/hr.
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If you email me (r.m.harrison@bham.ac.uk), I will send you a published paper with a peer-reviewed method for smaller air samples collected on 47mm filters.
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There has been some discussion in the recent literature on trace elements in speleothems about the importance of colloidal transportation of some elements,but the transportation of Pb, Cu, and Zn from the surface to the spelothems are not realy studied.
I would like know more about this subject, I hope this helps.
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I think climate induced chemical weathering of the overlying soil may be an important reason in natrural situation. If there are heave meta pollutions in the surrounding environment, they may be recorded in speleothems. Recently, we found a stalagmite from central China have recorded the Pb pollution in the environment because of Lead mining process during the last 30 years in this area.
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We used it for generating the highly adsorptive nitric acid vapor as an alternative for the permeation tube (discussed by Karl Cammann in these topics).
It is briefly described in
Artefacts in the sampling of nitrate studied in the “INTERCOMP” campaigns of EUROTRAC-AEROSOL
M. Schaap et al
Atmospheric Environment. 12/2004; 38(38):6487-6496
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Addition:
nitric acid is the end product of the oxidation of the nitrogen oxides in the atmosphere.
We measured nitric acid concentrations in Atlanta. In the Netherlands almost all nitric acid is neutralized by ammonia. The resulting ammonium-nitrate is a solid material, however so hygroscopic that this compound is indeed present as microdroplets. Also this investigated in great detail.
Harry
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In particular, I intend to make it more quantitative. Do you have particular problems and solutions you have used in class or in practice that you would like to see in this edition?
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Good suggestion. Will do!
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Can anyone provide me with information on freely available software packages for modelling Vehicular Exhaust Emissions within a a city.
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Yogesh, you can use CALINE4 model for vehicular emission prediction modelling. it's free version is also available. but i m not sure if it's free version can be used for street canyon modelling.
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Does anyone knows if there is some routine monitoring for CO2 in Belgium?
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No dear, for a tunnel VOC car emission study for which I need to know the CO2 background at the moment of the measurement
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I'd like to know the photolysis rate coefficient of NO2 in formation of ozone in urban environment and want to compare it with ground based observations
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As you can see in the previous entrée this has been answered already over 30 years ago. In addition to the publications mentioned there are dozens of free publications on the web that you can read. Just start to GOOGLE (you should have done so before asking us)
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I want to apportionment sources for PM 10 air samples after metal analysis in ICP.
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Here's the attachment.
Also check out:
ARAI (2009). Source profiling for vehicular emissions. Report Number ARAI/VSP-III/SP/RD/08-09/60 ; prepared by Autmotive Research Association of India, Pune, India, http://www.cpcb.nic.in/Source_Profile_Vehicles.pdf.
Sethi, V.; Patil, R.S. (2008). Development of Air Pollution Source Profiles - Stationary Sources Volume 1. prepared by Indian Institute of Technology, Mumbai, India, http://www.cpcb.nic.in/Source_Emission_%20Profiles_NVS_Volume%20One.pdf.
Sethi, V.; Patil, R.S. (2008). Development of Air Pollution Source Profiles - Stationary Sources Volume 2. prepared by Indian Institute of Technology, Mumbai, India, http://www.cpcb.nic.in/Source_Emission_Profiles_NVS_Volume%20Two.pdf.
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Required for air quality modelling.
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It is an acrimonious debate whether there is global warming or not. In recent times several instances have been cited in favour of global warming, including the raising of sea water, the melting of glaciers in both the North and South poles, as well as in the Himalayas. There is no doubt that there is an upsurge of CO2 in the atmosphere, besides other causal gases. Can the escalation of green cover come to our green planet's rescue? Or are there any other biological or chemical tools that can solve this burning problem?
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Glaciers have been melting for centuries so they are an indicator of natural warming.
Recent temperature data show a leveling off or even slight decrease in global temps.
Solar and wind will not provide enough power in many locations around the globe.
The best solution may be eliminating politicians from bloviating so much. The sure method is to blow up our sun. Then we will have about 8 minutes before everyone turning into popsicles.
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Is there any standard method for it? I dissolve them in acetonitrile but when I mixed the solution with water, precipitation occurs. How can the precipitation be prevented?
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It is very common error to try to spike too high concentration of hydrophobic analytes. You must look up the water solubility and never try to spike higher. It would be pointless and wrong to use too high concentrations. Acetonitrile is ok but as small amount as possible.
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Here in Spain, commercial, residential and domestic biomass burning is officially supported for climate reasons, but in urban agglomerations the effect on air quality may be very negative.
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FYI: The National Academies Press just released Opportunities and Obstacles in Large-Scale Biomass Utilization: The Role of the Chemical Sciences and Engineering Communities: A Workshop Summary. It should address some of the issues for here is the US.
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I want to find the height of the boundary layer to find the diurnal profile of air pollution
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I would first look at:
Benkley, Carl W., Lloyd L. Schulman, 1979: Estimating Hourly Mixing Depths from Historical Meteorological Data. J. Appl. Meteor., 18, 772–780.
and
Hennemuth, Barbara, and Andrea Lammert. "Determination of the atmospheric boundary layer height from radiosonde and lidar backscatter." Boundary-layer meteorology 120 (2006): 181-200.
Methods used are simple, but work relatively well in daytime well-mixed BL conditions.
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Concentrations of atmospheric pollutants are measured by various methods like field gas chromatography, apacity measurements, non-dispersive infra-red (NDIR), chemiluminescence; flame photometry, fluorescences etc but the relative contribution of sources like transportation, industrial, construction etc cannot be determined directly. What proxies are used to make such determinations?
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This is a very broad ranging question as the tracers or proxies are very dependent on the source you're interested in but as a very brief set of examples:
transportation: This is internal combustion of diesel or gasoline. What I normally use is particle number concentration as particles smaller than ~100 nm are normally associated to freshly emitted combustion particles. With vehicle technology advancing, CO is no longer significant in most of the developed world but NOx is a very decent traffic proxy (NO2 is cheaper to measure for long term assessments).
industry: This depends a lot on what kind of industry and fuel. Natural gas combustion is really hot and it is normally possible to identify when the plume of a gas fired burner hits a particular place by looking at the wind and NO2 measurements.
construction: This is mostly mechanically generated dust so I'd say that measuring PM2.5 AND TSP, the difference will be what's been generated as dust (TSP - PM2.5)
Biomass combustion (domestic wood fires, forest fires, etc): Levoglucosan has been used to quantitatively identify the fraction of wood combustion products on filter samples (but there are people who say that it doesn't work to quantify and only to identify wood smoke affected samples.
Diesel vs. Gasoline combustion products: Some people use black carbon and "uv-absorbing" carbon to discriminate (see papers on black carbon using a dual wavelength aethalometer). Also, as diesel combustion is hotter than gasoline in an engine, diesel produces more NOx and less CO than gasoline so it is possible to measure both and use NOx/CO as an indicator of diesel vs/ gasoline (higher values of the ratio correspond to diesel while lower values to gasoline)
I hope this helps and points you towards what you're looking for