Accession Number:

ADA106230

Title:

The Orographic Effects Induced by an Island Mountain Range on Propagating Tropical Cyclones.

Descriptive Note:

Memorandum rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

Report Date:

1981-10-30

Pagination or Media Count:

49.0

Abstract:

The orography effects on propagating tropical cyclone exerted by an idealized mesoscale, island mountain range was investigated by using a multi-layer primitive equation model with parameterized physics. The numerical simulation successfully reproduces the following observed behavior of the westward propagation tropical cyclones 1 The intensity of the tropical cyclone is reduced 2 the translating speed increases before passing the mountain ridge 3 the storm center moves cyclonically in passing over the mountain 4 the distribution of vertical motion is orographically modulated, upward motion occurs on the windside slopes where the vorticity is positive. The results indicated that the approaching tropical cyclone induces a cyclonic circulation around the topography. The mountain range constitutes a physical obstruction to the low-level flow and generates a strong easterly mass flow to the north of the mountain range.

Subject Categories:

  • Atmospheric Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE