Thursday, 15 January 2004
Quality controlled surface visibility observations used to validate predicted surface Aerosol concentration for Southwest Asia
The ability to accurately forecast reduced-visibility events that adversely affect flight operations is of critical importance to commercial and military planning and success. The Naval Research Laboratory (NRL) has developed the Navy Aerosol Analysis and Prediction System (NAAPS) to predict aerosol extinction, from which an estimate of visibility can be derived. The purpose of this paper is to validate predicted visibility trends and magnitude from a reliable and quality-screened visibility observation data set. Synoptic observations are carefully screened for consistency and quality prior to inclusion in the validation sample. Of the more than 1300 separate station reports covering Northeast Africa and Southwest Asia, less than 20% were selected which meet consistency and quality requirements. A contingency approach is carried out to estimate the predictive capabilities of the aerosol model in forecasting certain types of reduced-visibility events. In addition, the correlation between predicted and observed visibilities, and statistical trends with increasing forecast interval are presented.