Application of a microwave radiometer to study terrain-induced airflow disturbances at the Hong Kong International Airport

The thermodynamic profile in the atmospheric boundary layer, especially the presence of low-level inversion, is an important factor in terrain induced modifications of the airflow over HKIA. In Chan et al. (2006), a ground-based, multi-channel microwave radiometer placed downstream of the terrain was found to provide useful hints in the occurrence of terrain-induced airflow disturbances. The present study focuses on the applications of the radiometer in the monitoring of airflow disruption when it is placed upstream of the terrain.

The radiometer data collected in the field experiments in Hong Kong in 2004 and 2006 are considered in the study. Two approaches are adopted to illustrate the application potential of an upstream radiometer in the monitoring and forecasting of terrain-induced disturbances:-

(a) observational study of the relationship between the occurrence of mountain wake in the airport area and the upstream temperature profile as measured by the radiometer; and

(b) numerical modelling study initialized by the temperature profile from the radiometer, together with the wind profile from a radar wind profiler, to forecast mountain waves and wake.

Reference: P.W. Chan, K.C. Wu and C.M. Shun, 2006: Applications of a ground-based microwave radiometer in aviation weather forecasting. 13th International Symposium for the Advancement of Boundary Layer Remote Sensing