Classification of stratospheric extreme events according to their downward propagation to the troposphere

Abstract This study presents a classification of stratospheric extreme events during northern winter into events with or without a consistent downward propagation of anomalies to the troposphere. Anomalous strong and weak stratospheric polar vortex events are detected from daily time series of the p...

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Bibliographic Details
Main Authors: T. Runde, M. Dameris, H. Garny, D. E. Kinnison
Format: Article
Language:English
Published: Wiley 2016-06-01
Series:Geophysical Research Letters
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Online Access:https://doi.org/10.1002/2016GL069569
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Summary:Abstract This study presents a classification of stratospheric extreme events during northern winter into events with or without a consistent downward propagation of anomalies to the troposphere. Anomalous strong and weak stratospheric polar vortex events are detected from daily time series of the polar cap averaged (60°–90°N) geopotential height anomaly. The method is applied to chemistry‐climate model data (E39CA and WACCM3.5) and reanalyses data (ERA40). The analyses show that in about 80% of all events no significant tropospheric response can be detected. The stratospheric perturbation of both weak and strong events with a significant tropospheric response persists significantly longer throughout the stratosphere compared to the events without a tropospheric response. The strength of the stratospheric perturbation determines the strength of the tropospheric response only to a small degree. Results are consistent across all three data sets.
ISSN:0094-8276
1944-8007