The Replacement of a Climate-based Aerosol Approach with a Dynamic Aerosol Solution for Military Applications at the 557th Weather Wing

The 557^th Weather Wing (557WW) has requirements to provide aerosol information to support military mission planning and execution. In addition, the presence of aerosols impacts the evolution of sensible weather (e.g. temperature, clouds and precipitation). Currently, the primary aerosol information (outside of dust) in operations is based on a 10-year climatology of modeled aerosols developed using the Flow-following finite-volume Icosahedral Model Chemistry module (FIM-Chem). This climatology provides a grid-based solution of the optical properties for each specific day of the calendar year, but lacks the ability to inform the user of diurnal or other dynamic variabilities. In addition, this climatology has no ability to modify the sensible weather coming out of 557WW. A dynamic aerosol solution offers variability desired by the 557WW and its users.

The Global Air-Land Weather Exploitation Model (GALWEM), the 557th Weather Wing’s instantiation of the UKMO’s Unified Model (UM), contains a global aerosol scheme called the Coupled Large-Scale Aerosol Simulator for Studies in Climate (CLASSIC). GALWEM-CLASSIC supports up to eight aerosol species on a global domain through numerical weather modeling. A recent study of dynamic aerosol modeling using GALWEM-CLASSIC showed improvement of the 550nm AOD values globally versus using the climatology. GALWEM-CLASSIC was run at 17km horizontal resolution for the study and post-processed in the same manner as what was used to develop the aerosol climatology.

Based on these results, efforts are now underway to bring a version of GALWEM-CLASSIC into operations to provide dynamic aerosol evolution and impacts to sensible weather. We will present our design and early results.