Analysis of Boundary Layer Structure of Super Typhoon Meranti(1614)Using Wind Profiler Radar Data

WANG Xueyuan; WANG Lan; ZHENG Chenting; GUO Jianping

doi:10.16032/j.issn.1004-4965.2024.032

Abstract：This study employed wind profiler radar data from Xiang'an and radiosonde data from Xiamen to analyze the boundary layer structure in two distinct regions surrounding Super Typhoon Meranti in 2016:the outer rainband(120-220 km from the typhoon center)and the clear sky area(400-630 km from the typhoon center).The results showed that,in the outer rainband,the maximum tangential wind speed retrieved by the wind profiler radar was predominantly found 0.5-1.0 km below the inflow layer.As the typhoon center approached,the height of the maximum tangential wind speed and the height of the inflow layer exhibited a downward trend.The presence of rainfall particles,however,limited the wind profiler radar's capability to provide only qualitative assessment of the distribution patterns of the height of the maximum tangential wind speed and the height of the inflow layer in the outer rainband of the typhoon.In the clear sky area,the height of the maximum tangential wind speed was consistent with the height of the inflow layer,and the height of the boundary layer remained relatively stable,ranging between 1.2-1.6 km.This allowed for a quantitative representation of the boundary layer height distribution in the clear sky area around the typhoon.Compared with thermal turbulence,the turbulence in the boundary layer of the typhoon system was mainly driven by wind shear.The enhancement of the turbulence activities around the typhoon mainly occurred near the height of the maximum tangential wind speed.In addition to wind shear,there were other important driving forces,indicating more complex turbulence activities near the top of the typhoon boundary layer.More detailed turbulence flux experiments are needed to determine the driving forces of these activities.