Time-Altitude Variation of 30-Second-Update Full Volume Scan Data for Summer Convective Storms Observed With X-Band Dual Polarized Phased Array Weather Radar

Abstract

Dual-polarization radars with parabolic dish antennas, which transmit horizontal and vertical waves, are widely used to measure precipitation. However, such radars cannot properly observe the convective storms developing at high altitudes in a short time because of the low spatiotemporal resolution of the data due to mechanical scanning at azimuth and elevation angles. In 2018, an X-band dual-polarized phased array weather radar (DP-PAWR) was developed in Japan. DP-PAWR provides polarimetric precipitation measurements via three dimensional (3D) volume scanning in 30 s using electronic scanning at elevation angles. This study investigated the relationship between the amount of full volume scan data (the radar reflectivity factor( $Z_{h}$ ), differential reflectivity( $Z_{dr}$ ), and specific differential phase( $K_{dp}$ )) above the freezing level and that of near-surface rainfall for three characteristically different summer convective storms in Japan. We also discussed the quantitative predictability of near-surface rainfall volume using the full volume scan data above the freezing level obtained from DP-PAWR. The results showed that the 30-s full volume scan data above the freezing level can quantitatively predict near-surface rainfall volume for various storms, including heavy convective storms multi-precipitation cores, as well as small-scale convective storms with 5 t 11.5 minutes of lead-time.

Keywords

• Weather radar
• precipitation observation
• full volume scan data