Semi-annual oscillation of the global divergent circulation

Tsing-Chang Chen; Kuang-Der Wu

doi:10.3402/tellusa.v44i5.14967

Semi-annual oscillation of the global divergent circulation

Tellus

Volume 44 (1992): Issue 5

By: Tsing-Chang Chen and Kuang-Der Wu

Open Access

|Jan 1992

Abstract

The multi-year outgoing long-wave radiation (OLR) and velocity potential (χ) generated from the 200-mb wind fields of the National Meteorological Center and the European Centre for Medium-Range Weather Forecasts were used to examine the structure of the semi-annual divergent circulation and its relation with tropical cumulus convection. As inferred from the semi-annual mode of the asymmetric OLR component (OLR_E), the east’west differential response to the solar heating between the Asian-Australian (AA) monsoon (60°E–120°W) and the extra-AA monsoon (120°W–60°E) hemispheres sustains a distinct semi-annual mode of the asymmetric divergent circulation with a wavenumber-1 structure. This semi-annual mode of the asymmetric divergent circulation, represented by the asymmetric velocity potential (χ_E), develops in time coherently with the semi-annual mode of tropical cumulus convection, which indicates a faster response in the extra-AA monsoon hemisphere. That is, the negative centres of semiannual OLR_E anomalies and the divergent center of the semi-annual χ_E field appear in the extra-AA monsoon hemisphere in April/October and in the AA-monsoon hemisphere in January/July.

References

Chen , T.-C. and Baker , W. E. 1986 . Global diabatic heating during FGGE SOP-1 and SOP-2 . Mon. Wea. Rev . 114 , 2578 – 2589 .
Search in Google Scholar Back to article
Chen , T.-C. , Tzeng , R.-Y. and Yen , M.-C. 1988 . Development and life cycle of the Indian monsoon: Effect of the 30-50 day oscillation . Mon. Wea. Rev . 116 , 2183 – 2199 .
Search in Google Scholar Back to article
Holton , J. R. 1978 . An introduction to dynamic meteorology . Academic Press , 391 pp.
Search in Google Scholar Back to article
Jaeger , L. 1976 . Monatskarten des Niederschlags für die ganze Erde. Ber . Dt. Wetterd 18 , 139 , 38 pp.
Search in Google Scholar Back to article
Lambert , S. J. 1989 . A comparison of divergent winds from the National Meteorological Center and the European Center for Medium Range Weather Forecasts global analysis for 1980-1986 , Mon. Wea. Rev . 117 , 995 – 1005 .
Search in Google Scholar Back to article
Meehl. G. A. 1991 . A reexamination of the mechanism of the semi-annual oscillation in the Southern Hemisphere . J. Climate 9 , 911 – 926 .
Search in Google Scholar Back to article
Van Loon , H. 1967 . The half-yearly oscillation in middle and high southern latitudes and the careless winter . J. Atmos. Sei . 24 , 472 – 486 .
Search in Google Scholar Back to article
Van Loon , H. and Jenne , R. L. 1969 . The half-yearly oscillation in the tropics of the Southern Hemisphere . J. Atmos. Sci . 26 , 218 – 232 .
Search in Google Scholar Back to article
Van Loon , H. and Jenne , R. L. 1970 . On the half-yearly oscillation in the tropics . Tellus 22 , 391 – 398 .
Search in Google Scholar Back to article
Weickmann , K. M. and Chervin , R. M. 1988 . The observed and simulated atmospheric cycle. Part I: Global wind fields models . J. Climate 1 , 265 – 289 .
Search in Google Scholar Back to article
White , G. H. and Wallace , J. M. 1978 . The global distribution of the annual and semi-annual cycles in surface temperature . Mon. Wea. Rev . 106 , 901 – 906 .
Search in Google Scholar Back to article

Articles in this issue

DOI: https://doi.org/10.3402/tellusa.v44i5.14967 | Journal eISSN: 3035-9554

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Language: English

Page range: 357 - 365

Submitted on: Oct 1, 1991

Accepted on: Apr 8, 1992

Published on: Jan 1, 1992

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

© 1992 Tsing-Chang Chen, Kuang-Der Wu, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 44 (1992): Issue 5