RADAR VERTICAL PROFILES AND MELTING LAYER STUDIES FROM AN S-BAND DOPPLER POLARISATION-DIVERSITY RADAR CAMPAIGN IN SINGAPORE

摘要

From the studies of vertical profiles of radar parameters in Singapore we have seen that peaks in dBZ and LDR are related to different stages of the melting process. The peak in LDR is within 100 m of the bottom of the melting process. The peak in dBZ, found on average at 4.5 km a.m.s.l. in Singapore, lies half way between this peak in LDR and the 0℃ isotherm. The variation in the height of the 0℃ isotherm and the height of the peak in dBZ is no more than 450 m during the year, due to the relatively constant ground temperature in Singapore. The thickness of the melting layer is 450 m. The averaged profiles of stratiform and convective events show that convective events often extend to heights of 15 km, and that below the bright band there is a decrease in reflectivity as rain falls to the ground, possibly due to evaporation. Future work will focus on analysing more events and looking into the relationships between rainfall rate, melting layer thickness and enhancement in radar reflectivity.