Modelers' data archive—a collection of atmospheric transport and dispersion data sets

Atmospheric Transport and Dispersion (ATD) field and laboratory data are invaluable resources for understanding ATD processes, developing new algorithms, and evaluating model performance. Many experiments have been conducted since the 1950s. About 20 years ago, the authors put together an initial version of the Modelers' Data Archive (MDA) that included some major dense gas field data sets with funding from the U.S. Air Force and the American Petroleum Institute (API). The archive has been steadily growing in time, despite a lack of any subsequent funding, to include about 50 data sets that cover a wide range of conditions, e.g., different plume densities (dense, buoyant, and neutral), spatial scales ranging from 0.1 to 1,000 km, flat vs. complex terrain, daytime vs. nighttime conditions, surface vs. elevated release, point vs. line source, rural vs. urban land use, and episodic vs. routine releases. These data sets have been freely distributed to the scientific community, both domestically and internationally, and have contributed positively to a large body of research concerning ATD model development and evaluation. In some cases, MDA has become the only known source of certain data sets. This presentation discusses attributes and typical applications of MDA, and mentions other data centers of similar ATD data sets. It also discusses necessary components of a good data set, common problems with a data set, and the way forward to transform this “grassroots” effort in maintaining and distributing ATD data sets to a more sustainable setting.