Cyclonic vortices over South America

Prakki Satyamurty; Celeste da Conceição Ferreira

doi:10.3402/tellusa.v42i1.11870

Cyclonic vortices over South America

Tellus

Volume 42 (1990): Issue 1

By: Prakki Satyamurty and Celeste da Conceição Ferreira

Open Access

|Jan 1990

Abstract

It is observed from satellite cloud imagery that about 100 neutral vortices per year cross the South American continent between 15-60°S, and almost as many are generated or intensified in the same latitude belt between 30-70°W. There are more cyclogeneses in summer than in winter in contrast to the common idea that winter is the season of maximum extratropical cyclogenesis. The frequency of neutral vortices is higher in the transition seasons than in summer and winter. Neutral vortices move toward the east with a speed of about 20 m/s^-1, while the cyclones which develop over the region move south-eastward more slowly with an average speed of 12.5 m/s^-1. Vortices crossing the Andes with cyclonic vorticity in excess of 2 × 10-5 s^-1 have a 40% probability of producing intense convective systems near the east coast of the continent.

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Articles in this issue

DOI: https://doi.org/10.3402/tellusa.v42i1.11870 | Journal eISSN: 3035-9554

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Language: English

Page range: 194 - 201

Submitted on: Oct 31, 1988

Accepted on: Jun 29, 1989

Published on: Jan 1, 1990

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

© 1990 Prakki Satyamurty, Celeste da Conceição Ferreira, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 42 (1990): Issue 1