Abstract : 2G.3
Terrain-disrupted airflow over the Hong Kong International Airport (HKIA) in the southwest monsoon

P.W. Chan
pwchan@hko.gov.hk
Hong Kong Observatory

Terrain-induced airflow disturbances are the major cause of low-level windshear at HKIA. Previous studies of the disturbances mainly focus on the effect of Lantau Island in east to southeasterly winds. The present study is the first account of the impact of Lantau Island on the airflow in southwest monsoon, which prevails over the south China coast in the summer. Three typical types of terrain-disrupted airflow in southwest monsoon are analyzed, namely, reversed flow, wind streaks and waves. They are studied in depth using LIDAR observations and numerical simulations. The specific wind and thermodynamic structures of the background southwesterly flow that could be disrupted by the complicated Lantau terrain, resulting in low-level windshear have been identified.