Aircraft Observations of Tropical Cyclone Boundary Layer Turbulence over the South China Sea

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

1 Scopus Citations
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Author(s)

  • N. Sparks
  • K. K. Hon
  • P. W. Chan
  • S. Wang
  • T. C. Lee
  • R. Toumi

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)3773-3783
Journal / PublicationJournal of the Atmospheric Sciences
Volume76
Issue number12
Online published19 Nov 2019
Publication statusPublished - Dec 2019

Abstract

There have been no high-frequency aircraft observations of tropical cyclone (TC) eyewall boundary layer turbulence since two flights into Atlantic hurricanes in the 1980s. We present an analysis of the first TC boundary layer flight observations in the South China Sea by the Hong Kong Observatory comprising four eyewall penetrations. We derive the vertical flux of momentum and vertical momentum diffusivity from observed turbulence parameters. We observe negative (upward) vertical fluxes of tangential momentum near the eyewall consistent with a jet below the flight level near the radius of maximum wind. Our observations of vertical momentum diffusivity support a superlinear relationship between diffusivity and wind speed at the high wind speeds in the inner-core of TCs (power-law exponent of 1.73 +/- 0.20) while the few existing boundary layer hurricane observations in the North Atlantic suggest a more linear relationship.

Research Area(s)

  • HIGH-RESOLUTION SIMULATIONS, VERTICAL EDDY DIFFUSIVITY, PART I, PARAMETERIZATION, INTENSIFICATION, SENSITIVITY, EVOLUTION, MODEL

Citation Format(s)

Aircraft Observations of Tropical Cyclone Boundary Layer Turbulence over the South China Sea. / Sparks, N.; Hon, K. K.; Chan, P. W.; Wang, S.; Chan, J. C. L.; Lee, T. C.; Toumi, R.

In: Journal of the Atmospheric Sciences, Vol. 76, No. 12, 12.2019, p. 3773-3783.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal