Lakes Environmental Newsletter
Lakes Software Monthly Newsletter


Monthly Newsletter - July 2022

US EPA Releases AERMOD & AERMET Versions 22112, New AERMOD View & AERMET View Coming Soon

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On June 27, 2022, the U.S. EPA announced revisions to the AERMOD air dispersion model and AERMET, its meteorological data preprocessor. The updated model executables have been published on the SCRAM website. This update replaces all previous versions (21112):

A full list of changes for each model can be found on the AERMOD and AERMET web pages. Changes include:

  • A completely recoded AERMET model featuring:
    • A new pathway (PROG) specific to WRF & MM5 meteorological data
    • Option for a single, combined-stage input file
    • Reformatted intermediate files (EXTRACT, QAOUT) that are easier to read and transfer to external applications
    • New upper air data format (IGRA)
  • New ALPHA model formulations:
    • See this month’s Modeling Tip for a description of all the new additions and changes
  • Update of the GRSM NO2 conversion method from ALPHA to BETA status
  • Bug fixes such as correcting the double counted NO2 background concentrations in PVMRM
  • And more!

Lakes Environmental's team is hard at work implementing updates to AERMOD View, AERMET View, and the AERMOD parallel version (AERMOD MPI) to address the changes incorporated into Model Versions 22112.

We plan to release a new version of AERMOD View later this summer. Be on the lookout for an email from Lakes Environmental announcing the new release. If your maintenance is current, you will receive instructions on how to download the new version of AERMOD View that incorporates version 22112 updates.

If you are a user of AERMOD View but are no longer in maintenance, please contact our sales team at for pricing to update your software and be eligible for this important new release.

AERMOD Campaign

Lakes Environmental at A&WMA Conference and Exhibition

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Lakes Environmental would like to thank everyone who stopped by our booth in San Francisco at A&WMA’s Annual Conference and Exhibition from June 28-29, 2022.

We trust that you enjoyed your time at this year’s conference and look forward to working with you throughout the coming year. See you in 2023 at A&WMA’s next annual conference in Orlando!

Online AERMOD Training Course – Sep 20-21, 20222

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Our team will present 2 days of online AERMOD training on September 20 and 21, 2022 from 8:30am to 5:00pm (Central Time – Dallas, USA).

Register today!

Note: Due to the immense popularity of our online courses and small class sizes, we recommend registering and making payment as soon as possible.


AERMOD (September 20-21, 2022)



Online CALPUFF Course – Sep 27-28, 2022 - Space Filling Fast

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Don’t miss out on our next available 2-day online CALPUFF course taking place on September 27 and 28, 2022 (Central Time – Dallas, USA). The same great course, now from the convenience of your home or office!

Space is limited. Register today!


CALPUFF (September 27-28, 2022)



Lakes Environmental Closed for Ontario Civic Holiday

Lakes Environmental's Waterloo office will be closed on Monday, August 1, 2022 to observe the Ontario Civic holiday. Our Dallas support office will remain open on this day. If you have any support needs during that time, please e-mail us at Any sales inquiries will be responded to when our offices reopen on Tuesday, August 2, 2022.


2022 Course Schedule

Sep 20-21, 2022
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Sep 27-28, 2022
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Oct 18-19, 2022
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Nov 15-16, 2022
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Dec 13-14, 2022
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New ALPHA Options in AERMOD 22112

With the latest release of the AERMOD model dated 22112, the U.S. EPA has continued to expand the formulated capabilities of the model. Most of these updates have been added as ALPHA non-default options, a concept we covered in a previous modeling tip. AERMOD 22112 contains 6 new ALPHA options which are described below:

Platform Downwash

Taken from the Offshore and Coastal Dispersion Model (OCD), the U.S. EPA’s preferred model for calculating near-field air pollutant impacts from overwater emission sources, platform downwash algorithms have been integrated into AERMOD for point, horizontal point, and capped point sources.

After identifying the source – with the source’s height identified as the height above sea surface – the platform is identified with the following parameters:

  • Zelp: Height of the platform bottom above sea surface
  • Hb: Total height (above sea surface) of the tallest solid or “influential” building
  • Wb: The lesser width of buildings that can influence downwash when comparing side and end views of the platform (see the image below)

Modeling Tip picture
Platform downwash as considered by AERMOD 22112 (taken from U.S. EPA AERMOD User’s Guide [2022]).

TTRM2 NO2 Conversion Method

The Travel Time Reaction Method (TTRM) was first implemented as a stand-alone ALPHA option in AERMOD 21112. The new TTRM2 option was integrated to allow the model to assess TTRM simultaneously with existing NO2 conversion methods (PVMRM, OLM, & ARM2).

When TTRM2 is selected along with one of the other NO2 conversion methods, TTRM will be implemented for near-field receptors where the fraction of conversion remains below the upper limit of the equilibrium fraction (usually 0.90). For all other receptors, the other specific method is used.

Sidewash Point Source

This new specialized point source type was developed to further study the effect of the lateral shift of the building wake cavity that forms when the wind is oblique to one of the longer sides of an elongated building.

Unlike traditional point sources, sidewash points are defined by their location, height, emissions, and the dimensions of the rectangular building that will influence flow (width, length, and compass angle). This source is designed to only calculate concentrations within the building wake cavity, and it does not consider terrain, traditional plume rise (i.e., momentum vs. buoyancy), and PRIME downwash is not applied.

Modeling Tip picture
Depiction of SWPOINT Source from U.S. EPA AERMOD User’s Guide (2022)

RLINE Wind Speed Profile

This option (RLINEFDH) removes the displacement height used in the RLINE source algorithm for calculating the wind profile near the surface. With this option implemented, the wind speed profile is calculated similar to other AERMOD source types.

Low Wind Options

Two additional options have been added to the existing LOW_WIND keyword:

  1. FRANmin – A minimum value for the plume meander factor. Users could already restrict the maximum meander factor (FRANmax), and now they can control the minimum factor.
  2. PBAL – Overrides the default energy balance approach for plume meander to an alternate momentum balance approach.

AWMA Downwash Updates

For the AWMAUTURB & AWMAUTURBHX options, internal limits were modified (tiz from 50 to 18, tiy from 50 to 6).

Lakes Environmental’s development team is hard at work incorporating these new features into the AERMOD View application. A new version will be ready soon so users can begin testing and evaluating these new model options.



June 2022 Was Earth’s 6th-Warmest on Record

July 14, 2022 - June’s average global temperature continued 2022’s remarkably warm trend, as both the month and the year so far ranked sixth warmest on record.

Read more →

Using Compost Instead of Nitrogen as Fertilizer in Canada Can Slow Global Warming

July 14, 2022 - Greenhouse gas production is significantly less when biobased residues like compost replaces widely used nitrogen fertilizer during spring freeze-thaw events in cold temperate regions.

Read more →

Additional Environmental News

Visit the Environmental News Network (ENN), the most dependable online environmental news source!



2022 Conference Schedule

Guideline on Air Quality Models – Developing the Future
September 13-15, 2022 | Durham, North Carolina

Learn more →

Air & Waste Management Association Ontario Section’s 2022 Next Generation Ambient Air Monitoring Conference
September 13-14, 2022 | London, ON

Learn more →

Symposium Air & Odeurs Montréal 2022
October 26-27, 2022 | Montréal, Quebec

Learn more →


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