Wednesday, 23 January 2008
Improving numerical forecasting of the wind by using LIDAR data in the Local Analysis and Prediction System (LAPS)
Exhibit Hall B (Ernest N. Morial Convention Center)
Besides monitoring the wind in the vicinity of the Hong Kong International Airport (HKIA), the application of the LIDAR's velocity data to improve wind forecasting of a numerical weather prediction model over the airport is studied in this paper. The radial wind velocities obtained in three elevation scans of the LIDAR are ingested into LAPS. Together with the conventional surface anemometer, radar wind profiler and radiosonde measurements, a balanced dynamic field is created and used to initialize the Regional Atmospheric Modelling System (RAMS) for short-term forecasting of the wind in the airport area in the next several hours. Though only the analyzed wind field is used to start the model run, the LAPS analysis with the inclusion of LIDAR data is found to improve both the background dynamic and thermodynamic profiles of the boundary layer, which in turn lead to more realistic model simulation results. Two cases would be studied in this paper, namely, a spring-time easterly wind case in a stable boundary layer and gale-force southeasterly wind associated with a typhoon.