Improved Downburst Detection Algorithm using Doppler Radars in South Korea

Downburst (microburst) is a density current originated from precipitation-caused dragging force and evaporative cooling at the mature stage of a convective storm. The wind shears (strong wind from the downdraft, often damaging wind) in the lower altitude occurred by microburst endanger in the airport safety when flights’ take-offs and landings. Downburst is one of the most difficult weather phenomena to be detected and predicted considering its nature of being developed and dissipated in short time (in an hour). The algorithm Automated Microburst Detection Algorithm (AMDA) was developed using Airport Surveillance Radar 9 (ASR-9) focusing on the microburst in the airports. AMDA was applied to Weather Surveillance Radar (WSR-88D) recently to detect downbursts in any other regions including residential areas. AMDA detects wind-shear segments out to 70 km range from single WSR-88D by combining features from reflectivity and radial velocity fields. AMDA further modified to be applied to the Korean Doppler radar network as DownBurst Detection Algorithm (DBDA).

In this work, enhanced DBDA (eDBDA) developed to reduce false alarms in DBDA by extracting and combining downburst characteristics in the lowest two elevation angles. The features of downburst in plan position indicators (PPIs) were overlapped 1) to obtain the spatial confirmation and 2) to remove false alarms (not overlapped). Despite the scan intervals of Korean Doppler radar are longer (10 minutes) than that of AMDA (original version: 5 seconds and WSR-88D version: 4.5-10 minutes), it is shown that eDBDA detects downbursts with lesser false alarms.

Acknowledgment

This work was funded by the Korea Meteorological Industry Promotion Agency under Grant KMIPA 2015-1050.

This work was financially supported by the BK21 plus Project of the Graduate School of Earth Environmental Hazard System.