Accession Number:

ADA513327

Title:

Turbulence Structure of the Hurricane Boundary Layer Between the Outer Rainbands

Descriptive Note:

Journal article

Corporate Author:

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION MIAMI FL ATLANTIC OCEANOGRAPHIC AND METEOROLOGICAL LABS

Report Date:

2009-08-01

Pagination or Media Count:

15.0

Abstract:

As part of the Coupled Boundary Layers Air-Sea Transfer CBLAST-Hurricane program, flights were conducted to directly measure turbulent fluxes and turbulence properties in the high-wind boundary layer of hurricanes between the outer rainbands. For the first time, vertical profiles of normalized momentum fluxes, sensible heat and humidity fluxes, and variances of three-dimensional wind velocities and specific humidity are presented for the hurricane boundary layer with surface wind speeds ranging from 20 to 30 ms. The turbulent kinetic energy budget is estimated, indicating that the shear production and dissipation are the major source and sink terms, respectively. The imbalance in the turbulent kinetic energy budget indicates that the unmeasured terms, such as horizontal advection, may be important in hurricane boundary layer structure and dynamics. Finally, the thermodynamic boundary layer height, estimated based on the virtual potential temperature profiles, is roughly half of the boundary layer height estimated from the momentum flux profiles. The latter height where momentum and humidity fluxes tend to vanish is close to that of the inflow layer and also of the maximum in the tangential velocity profiles.

Subject Categories:

  • Meteorology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE