Dispersion Modeling Notes



AERMOD

On December 24, 2013, U.S. EPA released an updated version of the AERMOD model (v13350), as well as the meteorological preprocessing program, AERMET (v13350). The new versions are not anticipated to impact results significantly; rather the changes are more focused on new options associated with NO2 modeling and non-regulatory options for addressing low wind speeds in meteorological data. The release of the updates will likely require any ongoing modeling work which has not been submitted to the relevant agency to be redone in the new AERMOD prior to submission. For BREEZE users, an interim version (without sector-varying background concentrations or ozone background concentrations) of AERMOD, along with a fully implemented AERMET is available. The fully implemented AERMOD updated is expected in February.

ExDAM

For modelers of potential high explosive and vapor cloud explosions, BREEZE anticipates two significant releases of ExDAM shortly. First, the BREEZE developers have created a third module for BREEZE ExDAM, which can be used to import 3D maps directly from AutoCAD files. Secondly, BREEZE is planning to release ExDAM 8.5 in the near future. This new version will include the ability to convert structure blocks to horizontal or vertical cylinder and sphere shapes with just a few simple clicks, as well as the ability to change the People display size to better identify their location and analyze injury. Additionally, structure blocks can now be automatically converted to building structures; people can be automatically populated into rooms; and windows can be automatically created on selected walls. A new, robust “Recovery file” mechanism has also been implemented in this upcoming version. On top of these new, major features, BREEZE ExDAM 8.5 will include many new minor features, a handful of user interface enhancements, and various bug fixes.