The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region
The North Atlantic Oscillation (NAO) is generally regarded to largely be a product of processes internal to the troposphere. This thesis investigates various aspects of how the NAO and related climatical fields are influenced by two of the tropospheric boundary components; the stratosphere above and...
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Format: | Doctoral or Postdoctoral Thesis |
Language: | English |
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The University of Bergen
2009
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Online Access: | https://hdl.handle.net/1956/3502 |
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ftunivbergen:oai:bora.uib.no:1956/3502 2023-05-15T17:32:08+02:00 The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region Breiteig, Tarjei 2009-09-07 application/pdf https://hdl.handle.net/1956/3502 eng eng The University of Bergen Paper I: Geophysical Research Letters 35, Breiteig, T., Extra-tropical synoptic cyclones and downward propagating anomalies in the Northern Annular Mode, L07809. Copyright 2008 The American Geophysical Union. Full text not available in BORA due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1029/2007GL032972 Paper II: Kolstad, E. W.; Breiteig, T.; Scaife, A. A., 2009, The association between stratospheric weak polar vortex events and cold air outbreaks. Full text not available in BORA. Paper III: Breiteig, T., 2009, Tropospheric precursors of downward propagating anomalies in the Northern Annular Mode. Full text not available in BORA. Paper IV: Breiteig, T.; Stephenson, D. B.; Kvamstø, N. G., 2009, Local interactions between the North Atlantic Ocean and the NAO. Full text not available in BORA. Paper V: Breiteig, T., 2009, The association between a weakening AMOC and the ENSO and NAO interannual variability. Full text not available in BORA. urn:isbn:978-82-308-0854-2 (print version) https://hdl.handle.net/1956/3502 Tarjei Breiteig VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Meteorologi: 453 Doctoral thesis 2009 ftunivbergen https://doi.org/10.1029/2007GL032972 2023-03-14T17:42:50Z The North Atlantic Oscillation (NAO) is generally regarded to largely be a product of processes internal to the troposphere. This thesis investigates various aspects of how the NAO and related climatical fields are influenced by two of the tropospheric boundary components; the stratosphere above and the ocean below. The thesis consists of five manuscripts, three considering the role of the stratosphere, and two considering the role of the ocean. Data provided by the NCEP/NCAR re-analyses is used to investigate how anomalies in the stratospheric circulation relate to subsequent anomalies in various important climatic fields. The mean storm tracks are found to shift meridionally, although not symmetrically between the Pacific and the Atlantic regions (paper I). Following events of anomalously weak stratospheric circulation, a statistically significant shift in the storm track is found only over the Atlantic. The spatial temperature distribution is found to go through several spatially and temporally distinct stages (paper II). In key regions, including northern Asia, Europe and the oceanic areas off the east coast of North America, the probability of cold air outbreaks increases by 50 – 80% at various stages relative to the negative stratospheric circulation anomaly peak. The strongest cold air outbreak appears in Northern Asia several weeks before the stratospheric anomaly peaks. This cooling is associated with cold, northwesterly winds due to a strong high pressure anomaly centered above Northern Scandinavia. In a separate study (paper III), it is shown that this high pressure anomaly is a typical precursor of negative stratospheric circulation anomalies. It is found that it is associated with enhanced vertical wave propagation – which is known to favour negative stratospheric circulation anomalies. When the Scandinavian high precedes negative stratospheric circulation anomalies, the stratospheric anomalies become more intense, and stronger subsequent surface climate signals arise compared to events without a ... Doctoral or Postdoctoral Thesis North Atlantic North Atlantic oscillation University of Bergen: Bergen Open Research Archive (BORA-UiB) Pacific Geophysical Research Letters 35 7 n/a n/a |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Meteorologi: 453 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Meteorologi: 453 Breiteig, Tarjei The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Meteorologi: 453 |
description |
The North Atlantic Oscillation (NAO) is generally regarded to largely be a product of processes internal to the troposphere. This thesis investigates various aspects of how the NAO and related climatical fields are influenced by two of the tropospheric boundary components; the stratosphere above and the ocean below. The thesis consists of five manuscripts, three considering the role of the stratosphere, and two considering the role of the ocean. Data provided by the NCEP/NCAR re-analyses is used to investigate how anomalies in the stratospheric circulation relate to subsequent anomalies in various important climatic fields. The mean storm tracks are found to shift meridionally, although not symmetrically between the Pacific and the Atlantic regions (paper I). Following events of anomalously weak stratospheric circulation, a statistically significant shift in the storm track is found only over the Atlantic. The spatial temperature distribution is found to go through several spatially and temporally distinct stages (paper II). In key regions, including northern Asia, Europe and the oceanic areas off the east coast of North America, the probability of cold air outbreaks increases by 50 – 80% at various stages relative to the negative stratospheric circulation anomaly peak. The strongest cold air outbreak appears in Northern Asia several weeks before the stratospheric anomaly peaks. This cooling is associated with cold, northwesterly winds due to a strong high pressure anomaly centered above Northern Scandinavia. In a separate study (paper III), it is shown that this high pressure anomaly is a typical precursor of negative stratospheric circulation anomalies. It is found that it is associated with enhanced vertical wave propagation – which is known to favour negative stratospheric circulation anomalies. When the Scandinavian high precedes negative stratospheric circulation anomalies, the stratospheric anomalies become more intense, and stronger subsequent surface climate signals arise compared to events without a ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Breiteig, Tarjei |
author_facet |
Breiteig, Tarjei |
author_sort |
Breiteig, Tarjei |
title |
The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
title_short |
The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
title_full |
The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
title_fullStr |
The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
title_full_unstemmed |
The influence of the ocean and the stratosphere on climate persistence in the North Atlantic region |
title_sort |
influence of the ocean and the stratosphere on climate persistence in the north atlantic region |
publisher |
The University of Bergen |
publishDate |
2009 |
url |
https://hdl.handle.net/1956/3502 |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Paper I: Geophysical Research Letters 35, Breiteig, T., Extra-tropical synoptic cyclones and downward propagating anomalies in the Northern Annular Mode, L07809. Copyright 2008 The American Geophysical Union. Full text not available in BORA due to publisher restrictions. The published version is available at: http://dx.doi.org/10.1029/2007GL032972 Paper II: Kolstad, E. W.; Breiteig, T.; Scaife, A. A., 2009, The association between stratospheric weak polar vortex events and cold air outbreaks. Full text not available in BORA. Paper III: Breiteig, T., 2009, Tropospheric precursors of downward propagating anomalies in the Northern Annular Mode. Full text not available in BORA. Paper IV: Breiteig, T.; Stephenson, D. B.; Kvamstø, N. G., 2009, Local interactions between the North Atlantic Ocean and the NAO. Full text not available in BORA. Paper V: Breiteig, T., 2009, The association between a weakening AMOC and the ENSO and NAO interannual variability. Full text not available in BORA. urn:isbn:978-82-308-0854-2 (print version) https://hdl.handle.net/1956/3502 |
op_rights |
Tarjei Breiteig |
op_doi |
https://doi.org/10.1029/2007GL032972 |
container_title |
Geophysical Research Letters |
container_volume |
35 |
container_issue |
7 |
container_start_page |
n/a |
op_container_end_page |
n/a |
_version_ |
1766130105805963264 |