Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections
The El Niño–Southern Oscillation (ENSO) is a major driver of Northern Hemisphere wintertime variability and, generally, the key ingredient used in seasonal forecasts of wintertime surface climate. Modeling studies have recently suggested that ENSO teleconnections might involve both a tropospheric pa...
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ftncar:oai:drupal-site.org:articles_13303 2023-09-05T13:21:23+02:00 Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections Butler, Amy (author) Polvani, Lorenzo (author) Deser, Clara (author) 2014-02-01 application/pdf http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-020-369 https://doi.org/10.1088/1748-9326/9/2/024014 en eng Institute of Physics Publishing Environmental Research Letters http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-020-369 doi:10.1088/1748-9326/9/2/024014 ark:/85065/d7vx0hf7 Copyright 2014 IOP Publishing Ltd. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Text article 2014 ftncar https://doi.org/10.1088/1748-9326/9/2/024014 2023-08-14T18:38:46Z The El Niño–Southern Oscillation (ENSO) is a major driver of Northern Hemisphere wintertime variability and, generally, the key ingredient used in seasonal forecasts of wintertime surface climate. Modeling studies have recently suggested that ENSO teleconnections might involve both a tropospheric pathway and a stratospheric one. Here, using reanalysis data, we carefully distinguish between the two. We first note that the temperature and circulation anomalies associated with the tropospheric pathway are nearly equal and opposite during the warm (El Niño) and cold (La Niña) phases of ENSO, whereas those associated with the stratospheric pathway are of the same sign, irrespective of the ENSO phase. We then exploit this fact to isolate the two pathways. Our decomposition reveals that ENSOs climate impacts over North America are largely associated with the tropospheric pathway, whereas ENSOs climate impacts over the North Atlantic and Eurasia are greatly affected by the stratospheric pathway. The stratospheric pathway, which we here define on the basis of the occurrence of one or more sudden stratospheric warmings in a given winter, and whose signature projects very strongly on the North Atlantic Oscillation, is found to be present 60% of the time during ENSO winters (of either phase): it therefore likely plays an important role in improving seasonal forecasts, notably over the North Atlantic and the Eurasian continent. Article in Journal/Newspaper North Atlantic North Atlantic oscillation OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Environmental Research Letters 9 2 024014 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
The El Niño–Southern Oscillation (ENSO) is a major driver of Northern Hemisphere wintertime variability and, generally, the key ingredient used in seasonal forecasts of wintertime surface climate. Modeling studies have recently suggested that ENSO teleconnections might involve both a tropospheric pathway and a stratospheric one. Here, using reanalysis data, we carefully distinguish between the two. We first note that the temperature and circulation anomalies associated with the tropospheric pathway are nearly equal and opposite during the warm (El Niño) and cold (La Niña) phases of ENSO, whereas those associated with the stratospheric pathway are of the same sign, irrespective of the ENSO phase. We then exploit this fact to isolate the two pathways. Our decomposition reveals that ENSOs climate impacts over North America are largely associated with the tropospheric pathway, whereas ENSOs climate impacts over the North Atlantic and Eurasia are greatly affected by the stratospheric pathway. The stratospheric pathway, which we here define on the basis of the occurrence of one or more sudden stratospheric warmings in a given winter, and whose signature projects very strongly on the North Atlantic Oscillation, is found to be present 60% of the time during ENSO winters (of either phase): it therefore likely plays an important role in improving seasonal forecasts, notably over the North Atlantic and the Eurasian continent. |
author2 |
Butler, Amy (author) Polvani, Lorenzo (author) Deser, Clara (author) |
format |
Article in Journal/Newspaper |
title |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
spellingShingle |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
title_short |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
title_full |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
title_fullStr |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
title_full_unstemmed |
Separating the stratospheric and tropospheric pathways of El Niño-Southern Oscillation teleconnections |
title_sort |
separating the stratospheric and tropospheric pathways of el niño-southern oscillation teleconnections |
publisher |
Institute of Physics Publishing |
publishDate |
2014 |
url |
http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-020-369 https://doi.org/10.1088/1748-9326/9/2/024014 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Environmental Research Letters http://nldr.library.ucar.edu/repository/collections/OSGC-000-000-020-369 doi:10.1088/1748-9326/9/2/024014 ark:/85065/d7vx0hf7 |
op_rights |
Copyright 2014 IOP Publishing Ltd. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
op_doi |
https://doi.org/10.1088/1748-9326/9/2/024014 |
container_title |
Environmental Research Letters |
container_volume |
9 |
container_issue |
2 |
container_start_page |
024014 |
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1776201991643463680 |