Midwinter warmings in the southern hemisphere stratosphere in 1988

Abstract An analysis was made of intense midwinter warmings which took place in the southern hemisphere stratosphere during August‐September 1988. By using the southern hemispheric data‐set up to the 1 mb level provided by the Japan Meteorological Agency, it is found that the 30mb temperature increa...

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Bibliographic Details
Published in:Quarterly Journal of the Royal Meteorological Society
Main Authors: Hirota, I., Kuroi, K., Shiotani, M.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1990
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Online Access:http://dx.doi.org/10.1002/qj.49711649407
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.49711649407
https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.49711649407
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Summary:Abstract An analysis was made of intense midwinter warmings which took place in the southern hemisphere stratosphere during August‐September 1988. By using the southern hemispheric data‐set up to the 1 mb level provided by the Japan Meteorological Agency, it is found that the 30mb temperature increase over eastern Antarctica, about 60 K for 10 days from 22 August to 1 September, is associated with the amplification of a quasi‐stationary planetary wave of zonal wavenumber 1. the enhancement of wave 1 appears quasi‐periodically with a period of about 2 weeks during the midwinter of 1988. Clear evidence is presented to show that the quasi‐periodic amplification of wave 1 is due to the wave‐wave interaction between the quasi‐stationary forced wave of wavenumber 1 and the eastward travelling wave of wavenumber 2. It is emphasized, therefore, that the mechanism of warming in this case is quite different from that of the transient vertical propagation of a planetary wave forced from below as observed in the northern hemisphere winter.