short note
Observation and numerical simulation of terrain-induced airflow leading to low level windshear at the Hong Kong International Airport based on Range-Height-Indicator scans of a LIDAR
Chan, Pak Wai; Cheung, P.; Lai, K. K.
Meteorologische Zeitschrift Vol. 33 No. 3 (2024)
11 references
published: Jul 29, 2024
published online: Jun 5, 2024
manuscript accepted: Mar 11, 2024
final revised version received: Feb 26, 2024
manuscript revision requested: Feb 16, 2024
manuscript received: Jan 4, 2024
Open Access (paper may be downloaded free of charge)
Abstract
A Doppler Light Detection And Ranging (LIDAR) system is set up downstream of a small hill of Lantau Island near the Hong Kong International Airport to perform range-height-indicator (RHI) scans to monitor airflow disturbances by the terrain in a tropical cyclone case and to study the feasibility of alerting the low level windshear to be encountered by the aircraft leaving the airport. This is the first time that RHI scans are performed regularly downstream of the small hill. The scans show many interesting features of terrain-disrupted airflow, including tiny vortex of reverse flow and higher-speed wind streaks. The latter are found to be associated with the low level windshear reported by the pilots. The airflow features are simulated using a high resolution numerical weather prediction model. It turns out that the higher-speed wind streaks could be reproduced successfully. However, the reverse flow does not show up well in the simulation.
Keywords
windshear • terrain-disrupted airflow • range-height-indicator (RHI) • LIDAR • Hong Kong International Airport