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Modeling Tips

  • February 24, 2026

AERMOD View: When Numerical Values Are Outside AERMOD’s Default Threshold

A standard model run using the AERMOD air dispersion model produces numeric output with up to 13 significant figures (e.g., xxxxxxxx.xxxxx). Projects which use very low or very high emission rates may run into a problem where the values output by the model do not fit properly within this limit. For example, concentration values of 1E9 units or higher will result in a field of asterisks written to the output file as shown below.

  • January 20, 2026

AERMET Surface Data Changes

AERMET is the meteorological preprocessor used to prepare data into a format usable by the AERMOD modeling system. One of the four types of data ready by AERMET is hourly surface observations collected into one of several preformatted data file formats. For several years, the primary format used in AERMET’s Surface Pathway has been the Integrated Surface Hourly Database (ISHD) hosted by the National Centers for Environmental Information (NCEI).

  • December 11, 2025

AERMOD View: Time Series Output

The AERMOD model can produce many different forms of output to support modelers’ needs. For example, highest values (or ranked values) tables are probably the most common form of output. These tables contain concentrations which are not paired in time across the domain but ranked in order from highest to lowest at each individual receptor.

  • November 20, 2025

AERMOD View: EVENT Processing

When modeling with source groups in the AERMOD air dispersion model, it is not always obvious how much each source contributes to a calculated concentration. To facilitate source contribution analyses, AERMOD contains a routine called the EVENT model which can analyze user-specified events (e.g., design concentrations, threshold violations) and print each source’s contribution to the short-term (i.e., = 24 hours) event.

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  • October 21, 2025

Lakes Software Products: Copying Projects

There are many reasons why it may be necessary to create a copy of a modeling project. You may want to make edits to a scenario without overwriting previous results, or you need to re-run the project using a different set of meteorological data while maintaining the rest of the inputs.

  • September 23, 2025

AERMOD View: Running AERMOD & AERMOD MPI on a Second Computer

Did you know that a single license of AERMOD View allows you to perform multiple concurrent AERMOD runs on multiple computers? It’s true! When you install AERMOD View, several additional utility programs are included, and one of these – Batcher – allows modelers to set up a queue of model runs. Batcher can be executed from any computer where AERMOD View is installed even if the full application is not licensed.