Accession Number:

ADA218325

Title:

A Case Study of a Quasi-Stationary Tropical Convective Line

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1989-08-01

Pagination or Media Count:

95.0

Abstract:

An extreme case of a convectively dominated tropical convective system was investigated. Of particular interest is the observation that the nimbostratus anvil produced by the convective line was an order of magnitude smaller than most of the nimbostratus anvils, observed during GATE. Flight level data from the NCAR Electra was composited to examine the thermodynamic and kinematic structure of the convective line, of the environment, and of the wake. The boundary layer structure was studied using bulk aerodynamic surface fluxes and eddy correlation turbulence statistics. The review of the environmental thermodynamics showed that these factors did not control the velocity of the convective line or the production of nimbostratus anvil. The study of the kinematic structure and a review of previous studies determined that the ability of a convective line to produce nimbostratus anvil is a function of horizontal moisture advection from the convective region into the mesoscale stratiform anvil region. The advection of moisture into the mesoscale stratiform anvil region is controlled both directly and indirectly via across line shear and line speed. The bulk aerodynamic surface fluxes gave a wake recovery time on the order of 10 hours, and eddy correlation turbulence statistics were found to provide insight into the boundary layer forcing and turbulence structure. Theses.

Subject Categories:

  • Meteorology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE