Cross-mountain airflow as observed from flight data recorder (FDR) data of transport category commercial aircraft

The FDR data of arriving aircraft are analyzed to estimate the atmospheric quantities, including the three components of the wind and turbulent kinetic energy along the flight path. Two typical cases of terrain-disrupted airlfow at the Hong Kong International Airport area considered, namely, east to southeasterly wind case in spring-time and gale-force southeasterly wind associated with a typhoon. The FDR data are shown to reveal many mesoscale to microscale features of terrain-disturbed airflow, such as the turbulent wake behind the mountains and wave motion in the form of “roller-coaster” of vertical velocity. To study the features in detail, mesoscale numerical simulation would also be performed and compared with aircraft observations.