Lakes Environmental e-Newsletter

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Upcoming Courses

Date	Course	Location	Registration
Mar 24-25, 2015 Mar 26-27, 2015	AERMOD CALPUFF	Singapore	Register Now
May 4-5, 2015 May 6-8, 2015	AERMOD CALPUFF	Las Vegas, NV	Register Now
Jun 1-2, 2015 Jun 3-4, 2015	AERMOD CALPUFF	Edmonton, AB	Register Now
Oct 19-20, 2015 Oct 21-22, 2015	AERMOD CALPUFF	London, UK	Registration Coming Soon

For more information on the above courses, including registration information, location, and course outlines, please visit our web site: https://www.weblakes.com/courses.html.

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Modeling Tip

Long Term Averages in AERMOD

The AERMOD air dispersion model can calculate three different long-term averages: Month, Period, and Annual. The equation below demonstrates how these averages are calculated for a model run spanning a single year.

where
i	= Index ranging from 1 to Nhrs
Ci	= Concentration at hour i
Nhrs	= Number of hours in the averaging period
Nclm	= Number of calm hours in the averaging period
Nmis	= Number of missing hours in the averaging period

The Period and Annual averages will produce identical results for the single-year case. However, the results differ if multiple years are modeled together.

One major difference is that the Period average can be run for any start and end date. Whether the period is 1 hour, 1 day, 1 week, 1 month, 1 year, or 10 years, the Period average will report the concentration for the number of hours processed by the model. Annual averages, on the other hand, can only be run for periods containing complete years. The model issues a fatal error and stops processing if the period does not span the full 8,760 (or 8,784) hours.

This difference manifests itself in averages across multiple years. The Period average is effectively weighted according to how many non-calm, non-missing hours are present in each year. The Annual average across multiple years is performed by summing the individual annual averages and dividing by the number of years as shown below.

where
a	= Index ranging from 1 to Nyrs
Ca	= Concentration at year a
Nyrs	= Number of years in the model run

This means that running multiple years in a single run will output an average annual average. However, some regulatory agencies ask that annual averages be reported as the maximum annual average extracted from a certain number of years. In these cases, AERMOD must be run separately for each year in order to find the maximum.

Submit Your Modeling Tips Today!

We are currently accepting submissions for the Monthly Modeling Tip section that appears in our newsletters. If you have a modeling tip that may benefit our readers, please send it to us at support@webLakes.com. Your name and the name of your organization will appear below the tip providing you with an opportunity for increased exposure.

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Articles

European Environmental Agency Finds Air Pollution the Leading Environmental Cause of Death

January 6, 2015 – Responsible for 400,000 deaths each year globally, air pollution has yet to be sufficiently addressed by the world's governments, researchers have warned. Air pollution damages the heart. According to an expert position paper published in the European Heart Journal, many types of cardiovascular disease are linked to poor air quality.

Not only does air pollution exacerbate existing heart problems, but it also appears to play a role in the development of heart disease in otherwise healthy people, the researchers said. There is particularly strong evidence of the harmful effects of suspended particles, as opposed to gas pollution, they said.

Read Full Article Here

USEPA Memo: Transport for the 2008 Ozone NAAQS

January 22, 2015 - The USEPA issued a memo that will help states as they develop State Implementation Plans to address cross-state transport of air pollution for the 2008 ozone standards. This memo summarizes:

- Proven approaches used to address transport for previous ozone standards
- Results of EPA's preliminary air quality modeling data (PDF 155 pp) that characterizes ozone transport.

Read Full Article Here

USEPA Finalizes Updates to Air Standards for Future Wood Heaters

February 4, 2015 - WASHINGTON - The U.S. Environmental Protection Agency (EPA) is finalizing standards to limit the amount of pollution that wood heaters, which will be manufactured and sold in the future, can emit. These standards, which were last updated in 1988, reflect the significantly improved technology that is now available to make a range of models cleaner burning and more efficient. Today’s final rule will provide important health benefits to communities across the country and will be phased in over a five-year period, giving manufacturers time to adapt their product lines to develop the best next-generation models to meet these new standards. The final rule does not affect current heaters already in use in homes today. It also does not replace state or local requirements governing wood heater use. Instead, it ensures that consumers buying wood heaters anywhere in the United States in the future will be able to choose from cleaner-burning models.

Read Full Article Here

Breathe Uneasy: The Air that Indians Breathe is Dangerously Toxic

February 7, 2015 - In the early hours of a January morning, all lanes of a motorway into Delhi are crammed with hundreds of rumbling lorries. These are brightly painted, with signs imploring overtaking drivers to “Honk please”. Every night immense convoys like this one snake their way into the Indian capital, belching sulphurous diesel smoke. The sinking winter air presses the resulting smog tight over the city.

The lorries are a chief reason why Delhi’s air is now more toxic than any other city’s on earth. Admittedly Beijing has a worse reputation, with its visible smog from particulates of 10 microns or smaller, known as PM10. Delhi’s grim distinction is that it has even higher levels of PM10, as well as of the smaller particulates, PM2.5, that are more likely to kill because they go deeper into the lungs. Levels of PM2.5 in Delhi are routinely 15 times above levels considered safe by the World Health Organisation. New data suggest that, on this score, Delhi’s air has been 45% more polluted than that of the Chinese capital for the past couple of years.

Read Full Article Here

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Upcoming Conferences & Trade Shows

Date	Conference	Location
Mar 17-19, 2015	Americana 2015 More Info	Montréal, QC, Canada
Mar 29- Apr 3, 2015	38th Stationary Source Sampling & Analysis for Air Pollutants Conference More Info	Tucson, AZ, USA
Apr 12-16, 2015	U.S. EPA 2015 International Emission Inventory Conference More Info	San Diego, CA, USA
Apr 22-23, 2015	The Air Quality and Emissions Show 2015 More Info	Telford, United Kingdom
Apr 28-29, 2015	CANECT 2015 More Info Lakes Environmental will be at booth #1438	Toronto, ON, Canada
May 4-8, 2015	ITM 2015 – 34th International Technical Meeting on Air Pollution Modelling and its Application More Info	Montpelier, France
May 26-28, 2015	Carbon Expo 2015 More Info	Barcelona, Spain
Jun 15-19, 2015	Asia Clean Energy Forum More Info	Manila, Philippines
Jun 22-25, 2015	A&WMA 108th Annual Conference & Exhibition More Info Lakes Environmental will be at booth #506	Raleigh, NC, USA

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About this Newsletter

This newsletter contains information gleaned from various sources on the web, with complete links to the sources cited. Organizations cited are in no way affiliated with Lakes Environmental Software.

Lakes Environmental Software is a leading environmental IT company that offers a complete line of air dispersion modeling, risk assessment, emissions inventory, and emergency release software as well as training and custom software services. With satisfied users located around the globe, Lakes Environmental Software will continue to revolutionize the environmental software field.

For more information please visit our web site at: www.webLakes.com.  You may also contact us by phone at (519) 746-5995 or by fax at (519)746-0793.

All comments and suggestions are welcome.  You can e-mail us at: support@webLakes.com.

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