Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature
Weak stratospheric polar vortex (WPV) events during winter months were investigated. WPV events were identified as being weakest in December, accompanied by the most dramatic increase in geopotential height over the polar region. After the onset of a December WPV event, the dynamic processes influen...
Published in: | Atmospheric and Oceanic Science Letters |
---|---|
Main Authors: | , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
KeAi Communications Co., Ltd.
2019
|
Subjects: | |
Online Access: | https://doi.org/10.1080/16742834.2019.1640053 https://doaj.org/article/0d5a7059027840e295999eb00f8202ec |
id |
ftdoajarticles:oai:doaj.org/article:0d5a7059027840e295999eb00f8202ec |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:0d5a7059027840e295999eb00f8202ec 2023-05-15T17:35:11+02:00 Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature Cheng PENG Ke FAN Haixia DAI 2019-09-01T00:00:00Z https://doi.org/10.1080/16742834.2019.1640053 https://doaj.org/article/0d5a7059027840e295999eb00f8202ec EN eng KeAi Communications Co., Ltd. http://dx.doi.org/10.1080/16742834.2019.1640053 https://doaj.org/toc/1674-2834 https://doaj.org/toc/2376-6123 1674-2834 2376-6123 doi:10.1080/16742834.2019.1640053 https://doaj.org/article/0d5a7059027840e295999eb00f8202ec Atmospheric and Oceanic Science Letters, Vol 12, Iss 5, Pp 369-375 (2019) Stratospheric polar vortex weak stratospheric polar vortex events in December subseasonal variability stratosphere–troposphere interaction winter Eurasian air temperature (0–40 days) Environmental sciences GE1-350 Oceanography GC1-1581 article 2019 ftdoajarticles https://doi.org/10.1080/16742834.2019.1640053 2022-12-31T06:15:44Z Weak stratospheric polar vortex (WPV) events during winter months were investigated. WPV events were identified as being weakest in December, accompanied by the most dramatic increase in geopotential height over the polar region. After the onset of a December WPV event, the dynamic processes influencing Eurasian temperature can be split into two separate periods. Period I (lag of 0–25 days) is referred to as the stratosphere–troposphere interactions period, as it is mainly characterized by stratospheric signals propagating downwards. In Period I, a stratospheric negative Northern Annular Mode (NAM) pattern associated with the WPV propagates downwards, inducing a negative NAM in the troposphere. The anomalous low centers over the Mediterranean and North Pacific bring cold advection to northern Eurasia, resulting in a north-cold–south-warm dipole pattern over Eurasia. The zero line between negative and positive temperature anomalies moves southwards during days 5–20. Stratospheric cold anomalies at midlatitudes propagate downwards to high latitudes in the troposphere and contribute to the dipole structure. During Period Ⅱ (lag of 25–40 days), as downward signals from the stratosphere have vanished, the dynamic processes mainly take place within the troposphere. Specifically, a wave train is initiated from the North Atlantic region to northern Europe. The propagation of wave activity flux intensifies a cyclonic anomaly over northern Europe, which brings cold advection to Scandinavia and warm advection to central Asia. Therefore, a northwest-cold–southeast-warm dipole structure occupies Eurasia and migrates southeastwards during this period. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Pacific Atmospheric and Oceanic Science Letters 12 5 369 375 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Stratospheric polar vortex weak stratospheric polar vortex events in December subseasonal variability stratosphere–troposphere interaction winter Eurasian air temperature (0–40 days) Environmental sciences GE1-350 Oceanography GC1-1581 |
spellingShingle |
Stratospheric polar vortex weak stratospheric polar vortex events in December subseasonal variability stratosphere–troposphere interaction winter Eurasian air temperature (0–40 days) Environmental sciences GE1-350 Oceanography GC1-1581 Cheng PENG Ke FAN Haixia DAI Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
topic_facet |
Stratospheric polar vortex weak stratospheric polar vortex events in December subseasonal variability stratosphere–troposphere interaction winter Eurasian air temperature (0–40 days) Environmental sciences GE1-350 Oceanography GC1-1581 |
description |
Weak stratospheric polar vortex (WPV) events during winter months were investigated. WPV events were identified as being weakest in December, accompanied by the most dramatic increase in geopotential height over the polar region. After the onset of a December WPV event, the dynamic processes influencing Eurasian temperature can be split into two separate periods. Period I (lag of 0–25 days) is referred to as the stratosphere–troposphere interactions period, as it is mainly characterized by stratospheric signals propagating downwards. In Period I, a stratospheric negative Northern Annular Mode (NAM) pattern associated with the WPV propagates downwards, inducing a negative NAM in the troposphere. The anomalous low centers over the Mediterranean and North Pacific bring cold advection to northern Eurasia, resulting in a north-cold–south-warm dipole pattern over Eurasia. The zero line between negative and positive temperature anomalies moves southwards during days 5–20. Stratospheric cold anomalies at midlatitudes propagate downwards to high latitudes in the troposphere and contribute to the dipole structure. During Period Ⅱ (lag of 25–40 days), as downward signals from the stratosphere have vanished, the dynamic processes mainly take place within the troposphere. Specifically, a wave train is initiated from the North Atlantic region to northern Europe. The propagation of wave activity flux intensifies a cyclonic anomaly over northern Europe, which brings cold advection to Scandinavia and warm advection to central Asia. Therefore, a northwest-cold–southeast-warm dipole structure occupies Eurasia and migrates southeastwards during this period. |
format |
Article in Journal/Newspaper |
author |
Cheng PENG Ke FAN Haixia DAI |
author_facet |
Cheng PENG Ke FAN Haixia DAI |
author_sort |
Cheng PENG |
title |
Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
title_short |
Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
title_full |
Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
title_fullStr |
Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
title_full_unstemmed |
Sub seasonal variations of weak stratospheric polar vortex in December and its impact on Eurasian air temperature |
title_sort |
sub seasonal variations of weak stratospheric polar vortex in december and its impact on eurasian air temperature |
publisher |
KeAi Communications Co., Ltd. |
publishDate |
2019 |
url |
https://doi.org/10.1080/16742834.2019.1640053 https://doaj.org/article/0d5a7059027840e295999eb00f8202ec |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Atmospheric and Oceanic Science Letters, Vol 12, Iss 5, Pp 369-375 (2019) |
op_relation |
http://dx.doi.org/10.1080/16742834.2019.1640053 https://doaj.org/toc/1674-2834 https://doaj.org/toc/2376-6123 1674-2834 2376-6123 doi:10.1080/16742834.2019.1640053 https://doaj.org/article/0d5a7059027840e295999eb00f8202ec |
op_doi |
https://doi.org/10.1080/16742834.2019.1640053 |
container_title |
Atmospheric and Oceanic Science Letters |
container_volume |
12 |
container_issue |
5 |
container_start_page |
369 |
op_container_end_page |
375 |
_version_ |
1766134256095985664 |