Publication Date

2007-12-20

Availability

Open access

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PHD)

Department

Applied Marine Physics (Marine)

Date of Defense

2007-10-08

First Committee Member

William M. Drennan - Committee Chair

Second Committee Member

Hans C. Graber - Committee Member

Third Committee Member

Shuyi S. Chen - Committee Member

Fourth Committee Member

Peter G. Black - Committee Member

Abstract

As part of the ONR sponsored Coupled Boundary Layer/Air-Sea Transfer (CBLAST) experiment, data from the NOAA WP-3D research aircraft measurements into major Hurricanes in the 2002-2004 seasons are analyzed to investigate the structure of the boundary layer. The turbulent fluxes of momentum and enthalpy are derived using the eddy correlation method. For the first time, the momentum and enthalpy fluxes were directly measured in the boundary layer of a hurricane with wind speeds up to 30 m/s. A new bulk parameterization of the momentum and enthalpy flux is developed. The vertical structure of turbulence and fluxes are presented for the entire boundary layer in the rain free region between the outer rainbands. The turbulent kinetic energy budget was estimated for the hurricane boundary layer between the outer rainbands. The universal spectra and cospectra of the wind velocity, temperature and humidity are also derived. A case study on the effects of roll vortices on the turbulent fluxes is conducted, which confirmed the existence of the boundary layer rolls and gave the first estimate of their modulation of the momentum and sensible heat flux. The CBLAST data provided an invaluable perspective on the evaluation and development of the boundary layer parameterization suited for the hurricane models. Studies on entrainment processes above of the mixed layer and turbulent transport processes induced by the inflow are recommended in the future.

Keywords

Air-sea Interaction; Hurricane Boundary Layer Height; Turbulent Fluxes; Parameterization; Roll Vortices; Turbulent Kinetic Energy

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