WindTrax 2.0

WindTrax is a free software tool for simulating short-range atmospheric dispersion (for horizontal distances within about 1 km of the source). It has been designed as an easy-to-use graphical interface for assessment of turbulent transport on the micro-meteorological scale using Lagrangian stochastic particle models. The intention has been to make this type of analysis accessible to the many potential users (e.g. agronomists) who may not be experienced in micro-meteorological methods; to incorporate as much expertise within the program itself, so that users are freed from as much responsibility for knowledge of transport phenomenon as possible, while yet allowing experienced atmospheric scientists the flexibility to make appropriate adjustments.

Unique features

• calculates emission rate and downwind concentration from arbitrarily shaped area sources and point sources, simultaneously;
• handles both point and line-average (laser) concentration sensors;
• uses state-of-the-art Lagrangian stochastic models for dispersion calculations, in both forward and backward modes;
• estimates sensitivity of solution to source/sensor geometry in multiple source cases.

About the program

The approach to modeling in WindTrax is graphical, in that the simulation elements are represented by icons drawn on the screen. A plan-view map specifying the location of sources and sensors represents each experiment. Non-physical objects, such as data files and the underlying numerical models, are also represented by icons placed on the map. The background of the map itself represents the ground surface, which (in Version 1.0) is assumed to be horizontally homogeneous.

Using WindTrax

To create an experiment, the user selects objects such as area sources, point sources, anemometers, and concentration sensors from a palette, and drags them to the desired location on a blank map. Every feature of the map represents a physical or mathematical object, and by double clicking on it with the mouse, its properties can be edited. An arbitrary number of sources and sensors, of mixed types, can be present – though to estimate source emission rate, at least as many known concentrations as unknown sources must be present on the map.

WindTrax is free

WindTrax is available at no cost. You can download the installation file from this web site.

Your input is valued!

WindTrax has been improved considerably over the past seven years. I would like to hear from you if there are any features that you would like to see added or modified; my goal is to make WindTrax as useful a tool as possible.

The software has undergone extensive testing. As with any complex program, however, there is always opportunity for bugs to hide. Should you discover any problems, please contact help_at_thunderbeachscientific.com.  Bug reports will be given highest priority and a patch will be made available from the downloads page as soon as it is available.

For further information on WindTrax, please send an email to

windtrax_at_ThunderBeachScientific.com