Stratospheric influence on the tropospheric circulation revealed by idealized ensemble forecasts

Edwin Gerber, C. Orbe, L. M. Polvani

Research output: Contribution to journalArticle

Abstract

The coupling between the stratosphere and troposphere following Stratospheric Sudden Warming (SSW) events is investigated in an idealized atmospheric General Circulation Model, with focus on the influence of stratospheric memory on the troposphere. Ensemble forecasts are performed to confirm the role of the stratosphere in the observed equatorward shift of the tropospheric midlatitude jet following an SSW. It is demonstrated that the tropospheric response to the weakening of the lower stratospheric vortex is robust, but weak in amplitude and thus easily masked by tropospheric variability. The amplitude of the response in the troposphere is crucially sensitive to the depth of the SSW. The persistence of the response in the troposphere is attributed to both the increased predictability of the stratosphere following an SSW, and the dynamical coupling between the tropospheric jet and lower stratosphere. These results suggest value in resolving the stratosphere and assimilating upper atmospheric data in forecast models

Original languageEnglish (US)
Article numberL24801
JournalGeophysical Research Letters
Volume36
Issue number24
DOIs
StatePublished - Dec 2009

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stratosphere
forecasting
troposphere
heating
Atmospheric General Circulation Models
temperate regions
atmospheric general circulation model
vortex
persistence
forecast
vortices
sudden stratospheric warming
shift

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)
  • Geophysics

Cite this

Stratospheric influence on the tropospheric circulation revealed by idealized ensemble forecasts. / Gerber, Edwin; Orbe, C.; Polvani, L. M.

In: Geophysical Research Letters, Vol. 36, No. 24, L24801, 12.2009.

Research output: Contribution to journalArticle

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