Talk:Atmospheric dispersion modeling

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Snhing, JingxuanXiao.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 14:56, 16 January 2022 (UTC)

Rename to Air dispersal modeling

Most of links and references use that term and the existing title is offputting in its length :)...hope to hear from others on thisAnlace 18:56, 21 February 2006 (UTC)

As the primary author of the article, I disagree with you slightly. Having worked in the air dispersion modeling field for over 30 years, I am aware that it is often referred to as "air dispersion modeling" and as "atmospheric dispersion modeling". However, I have never seen the field referred to as "air dispersal modeling".

The reason for choosing the the current title when I contributed the article is simply that I felt it was more precise. The article is not about dispersion of the air nor about dispersion of the atmosphere. Rather it is about dispersion of air pollutants in the atmospheric air ... and therefore the current title is more precise.

I should point out that I also created the following pages all of which redirect the reader to the page as it is now titled:

• Atmospheric dispersion modeling
  
• Atmospheric dispersion modelling (for British Commonwealth readers)
• Air dispersion modeling
• Air dispersion modelling (for British Commonwealth readers)
• Air quality modeling
• Air quality modelling (for British Commonwealth readers)
• Dispersion modeling
• Dispersion modelling (for British Commonwealth readers)
• Air Dispersion
• Atmospheric Dispersion

If you really believe that the above list is inadequate, I would be happy to create another redirected page entitled "Air dispersal modeling". However, I strongly believe that the current title of the primary page is the most correct and most precise one. - mbeychok 00:42, 22 February 2006 (UTC)

thanks for your quick and detailed response. i am mainly trying to shorten the title and make it register with the general public. i am a scientist too and have been in the field 34 years. i agree the phrase i threw out makes little sense, but three of your other redirects would make good titles: [[Air quality modeling], Atmospheric dispersion modeling or Air dispersion modeling. would you be at peace with any of these? one of my motivations is that i am writing in a number of other air quality and environmental articles on wikipedia and it is nice to be able to use one term in the article which also becomes the title of the page to which it is linked. i think many readers get distracted when they click a link and the article title is different from the title she or he clicked. let me know what you think, best regards, Anlace 01:30, 22 February 2006 (UTC)

I still think the current title is more precise ... but, in the spirit of cooperation, I would be at peace with Atmospheric dispersion modeling. I will make the change as soon as I can. - mbeychok 03:08, 22 February 2006 (UTC)

How do I move history to this renamed page?

This page was developed by renaming and manually moving Dispersion modeling of air pollutants at the request of User:Anlace. I also changed all the pages linked or redirected to the old page to this renamed page so that they now link or redirect to this renamed page.

However, I do not know how to move the history of the old page and, thus, the history remains with the old page, namely Dispersion modeling of air pollutants. If anyone knows how to do that, please do so. - mbeychok 04:10, 22 February 2006 (UTC)

Regional and Global Air Quality modelling

If Air Quality modelling redirects here then I think regional and global models should also be mentioned here. These are grid point models in general and are used for air quality forecasting and scientific studies. The basic methodology of these models seems very different from approaches such as that of Gaussian Plume approaches and this needs to be reflected in the article. I am involved in global modelling of air pollution so my knowledge of regional modelling is limited and I am aware that these approaches are also now nested for example THOR.--NHSavage 07:50, 14 March 2006 (UTC)

I agree with you that regional and global models are different from the local scale, point source Gaussian models described in this article. I also agree that regional and global models are often nested or integrated with a number of modules. The purpose of this article was to introduce readers to the simplest fundamentals of dispersion modeling without writing a book ... which is what would be required to completely cover the entire field. If you will look carefully through Compilation of atmospheric dispersion models, you will see that I did include regional to global models there (in fact, I included NAMEIII developed by the UK Met Office).

The Category:Air dispersion modeling needs more articles. To that end, it would be quite helpful if you or one of your colleagues were to write an article on Air Quality Modeling. It would then be quite easy to change the current redirection of Air quality modeling and Air quality modelling to that new article. Would you be willing to do that?

Regards, mbeychok 17:06, 14 March 2006 (UTC)

I will give it some thought. However as I said I am working more at global scale and so it would require a fair amount of research. I don't want to rush into this. I also have a long list of other articles to edit...

Thanks for the comments though. --NHSavage 22:01, 14 March 2006 (UTC)

Mention of other models

I think there should be an explicit note about grid point models and maybe also something about urban dispersion modelling (street canyons etc.). Some details about gaussian models presented here could be moved into specialised article. --Vladimír Fuka 20:25, 10 September 2006 (UTC)

Vladimir, I agree that there are a great many types of dispersion models in use today. And I think that the major types do indeed deserve to have articles written about them. However, as I said in response to NHSavage (see above), this article was written to explain the fundamentals of the classic Gaussian dispersion algorithm and the classic Brigg's plume rise calculations. If we tried to include discussions of all the various modern dispersion models in use today, this article would become much, much too large. Rather than that, I think it would be much more useful if you (or anyone else) would write separate new articles about the other types of models. Is that something you would be willing to do? - mbeychok 23:49, 10 September 2006 (UTC)

Well, now i have not enough free time now, because i'm preparing for finals in meteorology. Then i can try write something, but i don't feel to be much competent. But again, if the name of article is Atmospheric dispersion modeling, there should be at the beginning short info about all possibilities. At least a short list or simple mention. Also there could be a separate article Gaussian dispersion models with more details about Sutton model etc. which can not be all in this introductional article.--Vladimír Fuka 15:07, 20 September 2006 (UTC)

Vladimer, good luck on your finals. As for mention of other models, the "See also" list in this article includes the article Compilation of atmospheric dispersion models which has descriptions of dozens of other models of various different types. The purpose of having a "See also" section is to do just what you are asking for ... a simple mention of other model types and other related articles ... is it not?? In my mind, there is no point of a short list of other models in this article when there is already an existing article with a very long list and description of other models. Regards, - mbeychok 15:27, 20 September 2006 (UTC)

define subject in first line please.

I notice that the article starts with a description on how Atmospheric dispersion modeling is done, not what it is. Could you please start the very first sentence by defining the subject clearly, including its purpose? Regards,Jens Nielsen 09:41, 24 March 2006 (UTC)

Thanks for your suggestion. I have revised the opening paragraph. - mbeychok 17:00, 24 March 2006 (UTC)

Reason for deleting CALINE and OCD model See also links

The CALINE and the OCD models, along with dozens of other worldwide individual models, are listed and briefly described in the Compilation of atmospheric dispersion models article which is listed in the "See also" section. So there is no point of listing any of the individual models in the "See also" section unless there is a separate Wiki article about an individual model (such as there is for each of the eight listed individual models). mbeychok 19:50, 18 November 2006 (UTC)

Observational Database

A large observational database of many different atmospheric constituents including radicals from a host of platforms is available. This was created as part of ESA Envisat and NASA Aura validation. It is of general use. Do you think it should be added to the article text? Dlary

As I explained when I deleted your external link to that observational data base, the link you provided led to a website that I found so difficult to understand that it was virtually incomprehensible. It was obviously written for the cognoscenti ... whereas this dispersion modeling article is no more than an introduction to the subject. Also, this dispersion modeling article does not include a discussion of atmospheric chemistry.

I have a great deal of respect for your very advanced expertise and credentials in the field of atmospheric chemistry. In my opinion, it would be much better if you wrote a separate article on that subject and how it relates to atmospheric pollutant dispersion modeling. Would you be willing to undertake writing such an article? Regards, - mbeychok 06:20, 3 February 2007 (UTC)

x parameter in the gaussian equation

I don't understand where the "x" parameter is used in the gaussian equation, as it doesn't appear anywhere. And if the "x" parameter is not in this equation, how to have a concentration in a point of the space (parameters x,y,z) while only 2 parameters (y and z) are used ?

fr:User:FredB —The preceding unsigned comment was added by 82.231.94.9 (talk) 13:45, 11 March 2007 (UTC).

Ok I think I have understood : the "x" parameter is used for $\sigma _{y}$ and $\sigma _{y}$. fr:User:FredB —The preceding unsigned comment was added by 82.231.94.9 (talk) 16:24, 11 March 2007 (UTC).

Yes, you found the correct answer to your question. - mbeychok 18:54, 11 March 2007 (UTC)

If you really believe that the above list is inadequate, I would be happy to create another redirected page entitled "Air dispersal modeling". However, I strongly believe that the current title of the primary page is the most correct and most precise one. - mbeychok 00:42, 22 February 2006 (UTC)

Typo?

Is there a missing "}" at the end of the definition of g3? Fig (talk) 13:38, 14 June 2011 (UTC)

Yes, you are right. I have now replaced the missing "}". mbeychok (talk) 19:22, 29 August 2012 (UTC)

Is photo representative?

The photo appears to show steam plumes rising from a stack and several cyclone separators at an industrial facility. Steam (water vapor) is not an air pollutant. Hence I wonder whether the photo is representative of "an industrial air pollution source." BobHerm (talk) 21:27, 10 April 2013 (UTC)

In general, when a photograph shows white plumes from industrial sources, the plumes are probably steam (water vapor) ... and many such plume photos are incorrectly identified as "pollution plumes". In this case, the photo came from a U.S. EPA website page (http://www.epa.gov/ttn/chief/) and that page is entitled "Clearinghouse for Inventories & Emissions Factors". If you right click on that image at that page and then click on "Image Info", you will see that the EPA labeled that image as "plantsmoke2.jpg". The inference is quite clear that the plume is not simply steam. In fact, the plumes are against a blue sky and do have a reddish brown tint to them that indicates they may not be simply clean steam.

I might add that the group of cyclones indicates to me that some particulates removal is occurring ... which would mean (unless the cyclones are removing 100% of the particulates) that the cyclone effluent plumes might still have some pollutant particulates in them.

All of that indicates to me that the photo is probably representative. However, if you have a photo with a darker plume against a blue sky, please feel free to replace the current photo. If you are unfamiliar with how to do that, then email me a copy of the photo along with the exact source of the photo as well as the date it was taken ... and I will upload it and replace the current photo. I stress the words "blue sky" because photos taken in the evening or at night (or photos taken with colored filters) can make all plumes look dark and polluted. mbeychok (talk) 23:54, 10 April 2013 (UTC)

Incorrect CFR Reference Third Paragraph ?

In the third paragraph, the last sentence reads, "At industrial facilities, this type of consequence assessment or emergency planning is required under the Clean Air Act (United States) (CAA) codified in part 60 of Title 40 of the Code of Federal Regulations."

If you are referring to the Risk Management Plan (RMP) requirements of §112(r) of the Clean Air Act, I believe they are codified at 40 CFR Part 68, not Part 60 (which is New Source Performance Standards under §111).

Regards, BobHerm (talk) 21:55, 10 April 2013 (UTC)

You are correct and I have made the change to Part 68. mbeychok (talk) 23:09, 10 April 2013 (UTC)

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Atmospheric Dispersion Parameters

The article does not include equations for the atmospheric dispersion parameters, σ_y and σ_z. They are dependent on the Pasquill Stability Class and equations for them are below:

σ_y(x) = exp(I_y + J_yln(x) + K_y[ln(x)]²)

σ_z(x) = exp(I_z + J_zln(x) + K_z[ln(x)]²)

units of σ_y, σ_z, and x are in meters.

Coefficient	A	B	C	D	E	F
Ry	0.443	0.324	0.216	0.141	0.105	0.071
ry	0.894	0.894	0.894	0.894	0.894	0.894
Iy	-1.104	-1.634	-2.054	-2.555	-2.754	-3.143
Jy	0.9878	1.0350	1.0231	1.0423	1.0106	1.0148
Ky	-0.0076	-0.0096	-0.0076	-0.0087	-0.0064	-0.0070
Iz	4.679	-1.999	-2.341	-3.186	-3.783	-4.490
Jz	-1.7172	0.8752	0.9477	1.1737	1.3010	1.4024
Kz	0.2770	0.0136	-0.0020	-0.0316	-0.0450	-0.0540

--Snhing (talk) 23:32, 26 April 2017 (UTC)

References

Pasquill Classification of Stability Classes

The classification of stability class is proposed by F.Pasquill. The six stability classes are referred to: A-extremely unstable B-moderately unstable C-slightly unstable D-neutral E-slightly stable F-moderately stable

References

Extra values in table of coefficients

The table under "Gaussian air pollutant dispersion equation" contain variables R_y and r_y which in p.998 of Seinfeld are used in the alternate derivation σ(x) = Rx^r. Since this formula isn't referred to elsewhere in the article, and all the analytical equations are supposed to produce the same coefficients anyways, I removed the two rows. — Preceding unsigned comment added by 30103db (talk • contribs) 13:07, 6 October 2021 (UTC)

Atmospheric dispersion and modelling

A talk Mizoreoluwa (talk) 02:03, 7 November 2023 (UTC)