Systemwide Events Calendar

Atmospheric Sciences Seminar

April 21, 3:30pm - 4:30pm
Mānoa Campus, Virtual Meeting

Improving Radar-Based Nowcasting by Blending Numerical Model Wind Information over Taiwan area

Dr. Kao-Shen Chung
Assistant Professor
Department of Atmospheric Sciences
National Central University, Taiwan

You are invited to a Zoom meeting.
When: April 21, 2021 at 3:30PM HST

Register in advance for this meeting: https://hawaii.zoom.us/meeting/register/tJYvfu2urD8jEtb2-aKc4ISPr4W9YuHre-tE

After registering, you will receive a confirmation email containing information about joining the meeting.

As a security precaution, unmuting microphones, starting video, screen share, and using the 'chat' feature will be disabled for those attending the seminar, except for ATMO faculty. If you would like to say something, please use the 'raise hand' feature. The host or a co-host can then enable you to unmute your microphone.

Abstract:
In this study, by using composite radar data from Central Weather Bureau (CWB), 16 typhoons are selected to examine the performance of the McGill Algorithm for Precipitation nowcasting using Lagrangian Extrapolation (MAPLE) over Taiwan area. In addition, instead of blending the precipitation between radar extrapolation and numerical model, information of wind is blended to improve the nowcasting system. It is found that the hybrid system could capture and maintain the circulation of rotation and rain-band structure much better than the original system. To validate the performance of nowcast, continuous, categorical, and neighborhood method (FSS score) are applied for verifications. For 16 typhoon cases, results of radar extrapolation show the quantitative precipitation nowcasting could last at least 2 hours. When blending the wind information from numerical model, it is able to improve the performance of nowcast for another 1 hour, which extends the capability of nowcast up to 3 hours. Furthermore, it is found the hybrid system performs better after typhoon landed over Taiwan even though orographic effect has to be considered.