Observations of boundary layer wind and turbulence of a landfalling tropical cyclone

Abstract

This study investigates the atmospheric boundary layer structure based on multiple-level tower observations with a height of 350 m during the landfall of Super Typhoon Mangkhut (2018). Results show a layer of log wind profile outside of the radius of maximum wind speed with a height of 100 m or larger. The log layer height increases with the wind speed. The height of the constant flux layer reaches ~ 300 m for 10-m wind speeds less than 13 m sāˆ’1 while this height decreases with the wind speed. Momentum fluxes and turbulent kinetic energy increase with the wind speed at all vertical levels. The drag coefficient and surface roughness length estimated at the tower location have values of 7.3 Ɨ 10ā€“3 and 0.09 m, respectively, which are independent of wind speed. The estimated vertical eddy diffusivity and mixing length increase with height up to ~ 160 m and then slowly decrease with height. The vertical eddy diffusivity increases with the wind speed while the vertical mixing length has no dependence on the wind speed. Comparing our results with previous work indicates that the vertical eddy diffusivity is larger over land than over ocean at a given wind speed range.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 30, 2022
Source ID
10.1038/s41598-022-14929-w

Entities

People

  • Chunxia Liu
  • Jun A. Zhang
  • P. W. Chan
  • Qilin Wan
  • Ruiquan Gao
  • Yong Zhu
  • Zhongkuo Zhao

Organizations

  • National Natural Science Foundation of China
  • National Oceanic and Atmospheric Administration
  • Office of Naval Research

Tags

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science/Meteorology
  • Mathematics or Statistics
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers