On the relation between NAO and water vapour transport towards Europe
In this study, the water vapour transport is investigated together with cyclone tracks across the North Atlantic Ocean and their relation to the North Atlantic Oscillation, NAO. During high NAO winters, the maximum of the water vapour transport across 10°W (defined as transport towards Europe) is ob...
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Language: | English |
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Online Access: | https://doi.org/10.1127/0941-2948/2002/0011-0395 |
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ftempa:oai:dora:empa_1233 2023-05-15T17:28:24+02:00 On the relation between NAO and water vapour transport towards Europe Ruprecht, Eberhard Schröder, Susanne Sandra Ubl, Sandy 2002 https://doi.org/10.1127/0941-2948/2002/0011-0395 eng eng Schweizerbart Meteorologische Zeitschrift--Meteorol. Z.--journals:2039--0941-2948 empa:1233 journal id: journals:2039 issn: 0941-2948 ut: 000180851100002 local: 6723 scopus: 2-s2.0-0036946582 doi:10.1127/0941-2948/2002/0011-0395 Text Journal Article 2002 ftempa https://doi.org/10.1127/0941-2948/2002/0011-0395 2023-03-04T17:17:51Z In this study, the water vapour transport is investigated together with cyclone tracks across the North Atlantic Ocean and their relation to the North Atlantic Oscillation, NAO. During high NAO winters, the maximum of the water vapour transport across 10°W (defined as transport towards Europe) is observed between 50° and 55°N, during low NAO winters, the maximum reduces from 160 kg/m·s to 120 kg/m·s and shifts to about 44°N. In order to understand this change the NCEP/NCAR reanalysis data (1958-1998) are used and a composite is performed of the cyclone's water vapour transport relative to the cyclone centre. The transport is strongest in the south-east sector of a cyclone. Its maximum increases with decreasing central pressure of the cyclone. Thus, deep cyclones transport more water vapour than shallow ones. During high NAO winters, deep cyclones are more frequent than in low NAO winters. Additionally, cyclone tracks are concentrated north of 55°N during high NAO winters and are rather equally distributed in meridional direction over the North Atlantic in low NAO winters. Since the water vapour content of the atmosphere over the North Atlantic increases towards the tropics, we found that during low NAO winters, the cyclones south of 55°N transport 60% more water vapour than those north of 55°N. This fact and the relation between cyclone properties and NAO can explain the shift of the maximum water vapour transport towards Europe from 55°N during high NAO winters to 44°N during low NAO winters. Article in Journal/Newspaper North Atlantic North Atlantic oscillation DORA Empa Meteorologische Zeitschrift 11 6 395 401 |
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language |
English |
description |
In this study, the water vapour transport is investigated together with cyclone tracks across the North Atlantic Ocean and their relation to the North Atlantic Oscillation, NAO. During high NAO winters, the maximum of the water vapour transport across 10°W (defined as transport towards Europe) is observed between 50° and 55°N, during low NAO winters, the maximum reduces from 160 kg/m·s to 120 kg/m·s and shifts to about 44°N. In order to understand this change the NCEP/NCAR reanalysis data (1958-1998) are used and a composite is performed of the cyclone's water vapour transport relative to the cyclone centre. The transport is strongest in the south-east sector of a cyclone. Its maximum increases with decreasing central pressure of the cyclone. Thus, deep cyclones transport more water vapour than shallow ones. During high NAO winters, deep cyclones are more frequent than in low NAO winters. Additionally, cyclone tracks are concentrated north of 55°N during high NAO winters and are rather equally distributed in meridional direction over the North Atlantic in low NAO winters. Since the water vapour content of the atmosphere over the North Atlantic increases towards the tropics, we found that during low NAO winters, the cyclones south of 55°N transport 60% more water vapour than those north of 55°N. This fact and the relation between cyclone properties and NAO can explain the shift of the maximum water vapour transport towards Europe from 55°N during high NAO winters to 44°N during low NAO winters. |
format |
Article in Journal/Newspaper |
author |
Ruprecht, Eberhard Schröder, Susanne Sandra Ubl, Sandy |
spellingShingle |
Ruprecht, Eberhard Schröder, Susanne Sandra Ubl, Sandy On the relation between NAO and water vapour transport towards Europe |
author_facet |
Ruprecht, Eberhard Schröder, Susanne Sandra Ubl, Sandy |
author_sort |
Ruprecht, Eberhard |
title |
On the relation between NAO and water vapour transport towards Europe |
title_short |
On the relation between NAO and water vapour transport towards Europe |
title_full |
On the relation between NAO and water vapour transport towards Europe |
title_fullStr |
On the relation between NAO and water vapour transport towards Europe |
title_full_unstemmed |
On the relation between NAO and water vapour transport towards Europe |
title_sort |
on the relation between nao and water vapour transport towards europe |
publisher |
Schweizerbart |
publishDate |
2002 |
url |
https://doi.org/10.1127/0941-2948/2002/0011-0395 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Meteorologische Zeitschrift--Meteorol. Z.--journals:2039--0941-2948 empa:1233 journal id: journals:2039 issn: 0941-2948 ut: 000180851100002 local: 6723 scopus: 2-s2.0-0036946582 doi:10.1127/0941-2948/2002/0011-0395 |
op_doi |
https://doi.org/10.1127/0941-2948/2002/0011-0395 |
container_title |
Meteorologische Zeitschrift |
container_volume |
11 |
container_issue |
6 |
container_start_page |
395 |
op_container_end_page |
401 |
_version_ |
1766121061744640000 |