Typical day Meteorological Data for Atmospheric Transport and Dispersion (ATD) modeling

The atmospheric transport and dispersion (ATD) model requirements for describing the environmental conditions that are most likely to occur on any given day, called the "typical day", are very unique. The model requirements are unique because the typical day requirements for ATD must be both typical in representing the most likely occurring condition of each variable and be mass-balanced across the domain of interest. This proposal is designed to address the typical day needs of military and civilian ATD model users so they can prepare more intelligently for toxic agent plume dispersion scenarios. Currently, ATD model users utilize gridded data from the 15th and 16th of each month from historical archives as meteorological input. This meets the mass balance requirement, but does not meet the most representative dispersion day requirement. The proposed work would investigate the use of four possible methods for selecting typical day data. The deliverable of the proposed work will be (1) a typical day selection method that works within the current concept of DoD operations, (2) information that gives the user an understanding of what the typical day data represents, and (3) a report documenting the details of the methods and research results.