Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic
This study examines the physical mechanisms that drive the poleward propagation of zonal-mean flow anomalies over the North Atlantic during the boreal winter with ECMWF ERA40 reanalysis data that spans the years 1958-2001. An empirical orthogonal function (EOF) analysis is performed on the zonal win...
Published in: | Quarterly Journal of the Royal Meteorological Society |
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Online Access: | https://hdl.handle.net/20.500.11897/148293 https://doi.org/10.1002/qj.2010 |
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ftpekinguniv:oai:localhost:20.500.11897/148293 2023-05-15T17:27:36+02:00 Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic Yuan, Jiacan Lee, Sukyoung Tan, Benkui Yuan, JC (reprint author), Peking Univ, Dept Atmospher & Ocean Sci, Sch Phys, Beijing 100871, Peoples R China. Peking Univ, Dept Atmospher & Ocean Sci, Sch Phys, Beijing 100871, Peoples R China. Penn State Univ, Dept Meteorol, State Coll, PA USA. 2013 https://hdl.handle.net/20.500.11897/148293 https://doi.org/10.1002/qj.2010 en eng quarterly journal of the royal meteorological society QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY.2013,139,(673,SI),992-998. 830151 0035-9009 http://hdl.handle.net/20.500.11897/148293 doi:10.1002/qj.2010 WOS:000320393800013 EI SCI poleward propagation wave breaking critical latitude North Atlantic LOW-FREQUENCY VARIABILITY GLOBAL CIRCULATION MODEL MEAN FLOW ANOMALIES CIRCUMGLOBAL TELECONNECTIONS OSCILLATION DYNAMICS WINTER MIDLATITUDE PACIFIC JET Journal 2013 ftpekinguniv https://doi.org/20.500.11897/148293 https://doi.org/10.1002/qj.2010 2021-08-01T07:58:22Z This study examines the physical mechanisms that drive the poleward propagation of zonal-mean flow anomalies over the North Atlantic during the boreal winter with ECMWF ERA40 reanalysis data that spans the years 1958-2001. An empirical orthogonal function (EOF) analysis is performed on the zonal wind anomalies for the North Atlantic domain. Based on time-lag correlations between the first two EOFs, 14 poleward propagation events are identified. A series of lagged composite calculations of the poleward propagation events reveals the following processes: midlatitude synoptic-scale Rossby waves propagate equatorward and break when they encounter their critical latitudes in the Tropics and Subtropics; a new critical latitude is generated slightly poleward of the previous critical latitude, and the subsequent wave breaking occurs at this new critical latitude. This interaction between the wave breaking and the critical latitude drives the poleward propagation of zonal-mean zonal wind anomaly. A comparison between the poleward propagation events and zonal index events indicates that the poleward propagation is associated with a relatively weak potential vorticity gradient over the Subtropics. These North Atlantic poleward propagation events are found to be preceded by anomalously strong transient eddy activity over the subtropical North Pacific, and by anomalously weak tropical convection over the tropical Atlantic Ocean and the Amazon. Copyright (c) 2012 Royal Meteorological Society Meteorology & Atmospheric Sciences SCI(E) EI 1 ARTICLE 673,SI 992-998 139 Journal/Newspaper North Atlantic Peking University Institutional Repository (PKU IR) Pacific Quarterly Journal of the Royal Meteorological Society 139 673 992 998 |
institution |
Open Polar |
collection |
Peking University Institutional Repository (PKU IR) |
op_collection_id |
ftpekinguniv |
language |
English |
topic |
poleward propagation wave breaking critical latitude North Atlantic LOW-FREQUENCY VARIABILITY GLOBAL CIRCULATION MODEL MEAN FLOW ANOMALIES CIRCUMGLOBAL TELECONNECTIONS OSCILLATION DYNAMICS WINTER MIDLATITUDE PACIFIC JET |
spellingShingle |
poleward propagation wave breaking critical latitude North Atlantic LOW-FREQUENCY VARIABILITY GLOBAL CIRCULATION MODEL MEAN FLOW ANOMALIES CIRCUMGLOBAL TELECONNECTIONS OSCILLATION DYNAMICS WINTER MIDLATITUDE PACIFIC JET Yuan, Jiacan Lee, Sukyoung Tan, Benkui Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
topic_facet |
poleward propagation wave breaking critical latitude North Atlantic LOW-FREQUENCY VARIABILITY GLOBAL CIRCULATION MODEL MEAN FLOW ANOMALIES CIRCUMGLOBAL TELECONNECTIONS OSCILLATION DYNAMICS WINTER MIDLATITUDE PACIFIC JET |
description |
This study examines the physical mechanisms that drive the poleward propagation of zonal-mean flow anomalies over the North Atlantic during the boreal winter with ECMWF ERA40 reanalysis data that spans the years 1958-2001. An empirical orthogonal function (EOF) analysis is performed on the zonal wind anomalies for the North Atlantic domain. Based on time-lag correlations between the first two EOFs, 14 poleward propagation events are identified. A series of lagged composite calculations of the poleward propagation events reveals the following processes: midlatitude synoptic-scale Rossby waves propagate equatorward and break when they encounter their critical latitudes in the Tropics and Subtropics; a new critical latitude is generated slightly poleward of the previous critical latitude, and the subsequent wave breaking occurs at this new critical latitude. This interaction between the wave breaking and the critical latitude drives the poleward propagation of zonal-mean zonal wind anomaly. A comparison between the poleward propagation events and zonal index events indicates that the poleward propagation is associated with a relatively weak potential vorticity gradient over the Subtropics. These North Atlantic poleward propagation events are found to be preceded by anomalously strong transient eddy activity over the subtropical North Pacific, and by anomalously weak tropical convection over the tropical Atlantic Ocean and the Amazon. Copyright (c) 2012 Royal Meteorological Society Meteorology & Atmospheric Sciences SCI(E) EI 1 ARTICLE 673,SI 992-998 139 |
author2 |
Yuan, JC (reprint author), Peking Univ, Dept Atmospher & Ocean Sci, Sch Phys, Beijing 100871, Peoples R China. Peking Univ, Dept Atmospher & Ocean Sci, Sch Phys, Beijing 100871, Peoples R China. Penn State Univ, Dept Meteorol, State Coll, PA USA. |
format |
Journal/Newspaper |
author |
Yuan, Jiacan Lee, Sukyoung Tan, Benkui |
author_facet |
Yuan, Jiacan Lee, Sukyoung Tan, Benkui |
author_sort |
Yuan, Jiacan |
title |
Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
title_short |
Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
title_full |
Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
title_fullStr |
Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
title_full_unstemmed |
Observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the North Atlantic |
title_sort |
observational evidence for the mechanism of the poleward propagation of zonal wind anomalies over the north atlantic |
publisher |
quarterly journal of the royal meteorological society |
publishDate |
2013 |
url |
https://hdl.handle.net/20.500.11897/148293 https://doi.org/10.1002/qj.2010 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
EI SCI |
op_relation |
QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY.2013,139,(673,SI),992-998. 830151 0035-9009 http://hdl.handle.net/20.500.11897/148293 doi:10.1002/qj.2010 WOS:000320393800013 |
op_doi |
https://doi.org/20.500.11897/148293 https://doi.org/10.1002/qj.2010 |
container_title |
Quarterly Journal of the Royal Meteorological Society |
container_volume |
139 |
container_issue |
673 |
container_start_page |
992 |
op_container_end_page |
998 |
_version_ |
1766119771716190208 |