open access

https://hdl.handle.net/2115/1438

What kind of stratospheric sudden warming propagates to the troposphere?

英語

2006-02-16

American Geophysical Union

Geophysical Research Letters

33

L04801

An edited version of this paper was published by AGU. Copyright 2006, American Geophysical Union, Geophysical Research Letters, 33

The factors affecting the downward propagation of stratospheric sudden warming (SSW) events to the troposphere are studied through composite analysis of 45-year reanalysis data from the European Centre for Medium-Range Weather Forecasts. During the growth stage of SSW, events that propagate into the troposphere exhibit enhanced upward flux of the wavenumber 2 wave, while events that do not propagate downward display reduced wavenumber 2 flux. In both events, upward flux of the wavenumber-1 wave is enhanced, but the enhancement is stronger in the non-propagating event. The composite for propagating events reveals a negative Eurasian pattern of horizontal geopotential anomalies in the troposphere during the growth stage, and a negative Arctic Oscillation pattern following the event, while non-propagating events are preceded by a positive Eurasian pattern. In both types of event, the tropospheric anomalies are generated mainly by tropospheric planetary wave forcing prior to the emergence of SSW.

学術雑誌論文

Accepted Manuscript

0094-8276