ISC-AERMOD View Version 5.4 Released!

Lakes Environmental is proud to announce the release of ISC-AERMOD View Version 5.4 on September 27, 2006. Some of the features in this new version include the ability to view your sources in the Building Inputs dialog, improvements to the Coordinate Converter and an update to the DXF Reader. For an extensive list of all the changes and new options to ISC-AERMOD View, please see our the latest release notes.

If you are currently in maintenance and did not receive an email regarding the update, please contact us at support@weblakes.com.

If you are a user of ISC-AERMOD View but are no longer in maintenance, contact us at info@weblakes.com for appropriate pricing information for your maintenance renewal.

Dr. Jesse Thé Selected as Session Chair for US EPA Emissions Inventory Conference

Dr. Jesse Thé has been selected to be a co-chair at the 2007 Emissions Inventory Conference, specifically for the section “Tools - Web-Based/Information Systems”.

This annual conference covers a wide range of subjects related to state-of-the-art techniques for developing emission inventories and several aspects of emission inventory preparation and use.

Dr. Jesse Thé is the president and founder of Lakes Environmental Software Inc.

Global Meteorological Data Available from Lakes Environmental Software

Lakes Environmental Software is now preparing global meteorological data for the CALPUFF, AERMOD, and ISCS air dispersion models. Data is created using the MM5 model and further processed to be compatible with the above mentioned models.

For pricing and other information related to this new service, please contact our sales team by emailing sales@weblakes.com.

We’ve set a number of training dates for 2006, with additional courses to be announced. Please contact us at training@weblakes.com for international or customized training inquiries.

Courses Filling up!

Our Orlando AERMOD Course is filling up - register now to book your spot!

AERMOD Courses

*Includes new section regarding MOE Reg. 419/05 (see Outline).

CALPUFF Courses

For more information on these courses, such as registration information and course outlines, please visit our web site: https://www.weblakes.com/courses.html.

Customized Courses

Lakes Environmental offers a variety of on-site, customized courses for all of your air dispersion modeling needs.  For information on pricing and availability, please email us at training@weblakes.com.

How AERMOD Treats Averaging Periods and Calms

When analyzing results from the US EPA AERMOD model, it is important to understand how concentrations for different averaging periods are being calculated.

Short Term Averages

Short term averages in AERMOD are 1, 2, 3, 4, 8, 12 and 24 hour averages.

In a straightforward situation where calm and missing hours are not present, short term average concentrations are calculated as we would expect:

Where

i is an index ranging from 1 to Nhrs
C_i = concentration at hour i
N_hrs = number of hours in the averaging period

However, when calm or missing hours are present, AERMOD will calculate a concentration of 0 µg/m³ for these hours. This raises the question of whether these hours should be included in the denominator of the above equation when average concentrations are calculated. The AERMOD code answers this question by modifying the equation in the following way:

Where

N_clm = number of calm hours in the averaging period
N_mis = number of missing hours in the averaging period
Max = is the maximum function
Round = rounds the number to the nearest integer.

Notice that the denominator (S_num) of the average concentration equation will exclude any calm or missing hours, but will not fall below ¾ of the total number of hours in the averaging period (rounded up to the nearest integer).

This is perhaps best illustrated by the examples below:

• Using equation 2 above, a three hour average (over the first three hours) would          result in a value of 4 µg/m³:

• An eight hour average would result in a value of 7 µg/m³:

Long Term Averages

Long term averages in AERMOD are Month, Period and Annual averages.

The rules for short term averages described above do not apply to long term averages. Long term averages are calculated as follows:

This means that only the hours that are non-calm and non-missing are included in the denominator, which is different from the way the denominator in Equation 2 (S_num) is calculated.

Note: All the above procedures are also true for the US EPA ISCST3 and ISC-PRIME models.

We are currently accepting submissions for the Monthly Modeling Tip which appears in our newsletters.  If you have a modeling tip that may benefit a variety of people, 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 greater exposure.

Clean Air Act to be Introduced Next Week

Prime Minister Stephen Harper was in Vancouver today to announce that a federal Clean Air Act will be introduced in the House of Commons next week, containing measures to reduce smog-forming pollutants and greenhouse gas regulations. Voluntary targets will be replaced with mandatory, ‘intensity-based’ emissions limits, he indicated.

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Can the EPA Regulate CO2?

At the end of August, a coalition of environmental groups, states, cities, religious organizations, power companies and a ski resort filed briefs before the court seeking a ruling on whether the EPA has the authority and the duty to regulate greenhouse gases such as CO2 that are emitted from automobiles and power plants.
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Japan Tuna Quota Halved for the Next Five Years

Japan's annual fishing quota for southern bluefin tuna, a sought-after delicacy in the world's largest fish consumer, will be halved for the next five years due to Tokyo's overfishing, a government agency said on Monday.
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Could Cosmic Rays have Helped Cause Global Warming?

For the past four years, physicist Henrik Svensmark has been making clouds inside a box. He mixed a few atmospheric gases, and then bombarded them with UV rays and heavy electrons.
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Antique Whale Oil Provides Insights to Origin of Pre-Industrial Chemicals

One of the last New England whaling ships has provided unexpected insights into the origin of halogenated organic compounds (HOCs) that have chemical and physical properties similar to PCBs and the pesticide DDT. HOCs are found everywhere and degrade slowly, but some are naturally produced and others produced by humans.

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Is Ontario Neglecting its Environment?

Ontario has a “fundamental neglect of the environment” that will have serious long-term consequences, says the Environmental Commissioner of Ontario (ECO). Issues facing the province include a lack of progress on solid waste diversion, potentially toxic aging landfills, no strategy for adapting to climate change, and an inadequate ‘cap-and-trade’ scheme for reducing industrial pollutants, according to the Commissioner’s 2005-06 annual report.
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U.S. Population on Track to 300 Million

America's population is on track to hit 300 million on Tuesday morning, and it's causing a stir among environmentalists. People in the United States are consuming more than ever - more food, more energy, more natural resources. Open spaces are shrinking and traffic in many areas is dreadful.
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Here are a few Conferences and Tradeshows coming up in the next few months: