84th AMS Annual Meeting

Thursday, 15 January 2004
COAMPS Dust Forecasting for Operation Iraqi Freedom
Room 4AB
Ming Liu, NRL, Monterey, CA; and D. L. Westphal, A. L. Walker, K. A. Richardson, S. D. Miller, and T. R. Holt
Dust storms generated by wind erosion over arid or semiarid land surfaces and transported long distances cause many adverse environmental problems in broad areas. The Naval Research Laboratory (NRL) in Monterey California has developed a Eulerian dust aerosol model and fully coupled to the Navy’s operational mesoscale prediction system COAMPS as an on-line module, using exact meteorological fields at each time step and each grid point on each grid mesh. The model was applied in both a research and pseudo-operational mode with focus on Iraq area and the Persian Gulf during the period of Operation Iraqi Freedom 2003, running twice a day to produce 3-day dust forecasts at 9, 27 and 81-km grid resolutions. The daily forecasts were included in the dust discussion product of Navy’s Fleet Numerical Meteorology and Oceanography Center. The Southwest Asia has large area coverage of deserts and the dusts provide a significant contribution to the regional aerosol and the global aerosol budget. Spring season has the highest frequency of dust storm occurrence. COAMPS allows two-way grid interaction so that dust lifted over Sahara in the 81-km domain (or the Mid-East in the 27-km) is transported to Iraq, as is often observed. Likewise, dust lifted in the 9-km grid is exported to the coarser domains. The model successfully forecasted intense weather systems and dust events, including the sandstorms of March 25-28 that grounded the U. S. Air Force. The high-resolution model also predicted detailed dust frontal structure in associated with cold front dynamic forcing. The model performance has been evaluated by comparisons with observations for the timing, strength and spatial coverage of dust plumes. The forecasts will be analyzed to study various-scale dynamic forcing in relationship to the dust life cycle of mobilization, transport and removal in Southwest Asia.

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