HR: 1340h
AN: A33A-0863    [Abstracts]
TI: Validation of Real-time Dust Forecasting for the Iraq Region of Southwest Asia
AU: * Liu, M
EM: liu@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AU: Westphal, D L
EM: westphal@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AU: Walker, A L
EM: walker@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AU: Holt, T R
EM: holt@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AU: Richardson, K A
EM: richardson@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AU: Miller, S D
EM: miller@nrlmry.navy.mil
AF: Naval Research Laboratory, 7 Grace Hopper Ave., Monterey, CA 93943 United States
AB: Dust storms are a significant weather phenomenon in the Iraq region in spring. Real-time dust forecasting using the Navy­_s Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS? with an inline dust aerosol model was conducted for the Operation Iraqi Freedom (OIF) in March and April 2003. Daily forecasts of dust mass concentration, visibility and optical depth were produced out to 72 hours on nested grids of 9-, 27- and 81-km resolution. In this work, the model performance is evaluated using ground weather reports, visibility observations, and enhanced satellite retrievals. COAMPS successfully predicted the timing, magnitude, duration and spatial coverage of the five major dust episodes. A detailed validation of the severest dust storm of OIF shows the high-resolution forecasts of the dust front are consistent with satellite images and the corresponding cold front observations. A statistical analysis of dust visibility for the OIF period reveals that COAMPS generates higher bias, RMS and relative errors at the stations having high frequency of dust storms, and that the errors are resolution dependent with the 9-km grid errors being the lowest. The calculation of forecast rates shows COAMPS achieved a dust storm prediction rate of 50 to 90% and threat score of 0.3 to 0.55 at the stations with frequent dust storms. Overall it predicted more than 85% of the observed dust and non-dust weather at all stations. A comparison of the forecast rates and statistical errors for the forecasts of different lengths (12 to 72 hours) for both dust and dynamics fields reveals little dependence of model accuracy on forecast length, implying that COAMPS accurately and consistently forecasted the severest of the OIF dust events. (COAMPS?is a registered trademark of the Naval Research Laboratory).
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 3355 Regional modeling
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005