Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation
The physical mechanisms whereby the mean and transient circulation anomalies associated with the North Atlantic Oscillation (NAO) drive winter mean precipitation anomalies across the North Atlantic Ocean, Europe, and the Mediterranean Sea region are investigated using the European Centre for Medium-...
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Language: | English |
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2020
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Online Access: | https://doi.org/10.1175/JCLI-D-20-0011.1 |
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ftncar:oai:drupal-site.org:articles_23899 2024-04-28T08:29:33+00:00 Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation Seager, Richard (author) Liu, Haibo (author) Kushnir, Yochanan (author) Osborn, Timothy J. (author) Simpson, Isla R. (author) Kelley, Colin R. (author) Nakamura, Jennifer (author) 2020-08-15 https://doi.org/10.1175/JCLI-D-20-0011.1 en eng Journal of Climate--0894-8755--1520-0442 articles:23899 ark:/85065/d7377d1j doi:10.1175/JCLI-D-20-0011.1 Copyright 2020 American Meteorological Society (AMS). article Text 2020 ftncar https://doi.org/10.1175/JCLI-D-20-0011.1 2024-04-04T17:34:52Z The physical mechanisms whereby the mean and transient circulation anomalies associated with the North Atlantic Oscillation (NAO) drive winter mean precipitation anomalies across the North Atlantic Ocean, Europe, and the Mediterranean Sea region are investigated using the European Centre for Medium-Range Weather Forecasts interim reanalysis. A moisture budget decomposition is used to identify the contribution of the anomalies in evaporation, the mean flow, storm tracks and the role of moisture convergence and advection. Over the eastern North Atlantic, Europe, and the Mediterranean, precipitation anomalies are primarily driven by the mean flow anomalies with, for a positive NAO, anomalous moist advection causing enhanced precipitation in the northern British Isles and Scandinavia and anomalous mean flow moisture divergence causing drying over continental Europe and the Mediterranean region. Transient eddy moisture fluxes work primarily to oppose the anomalies in precipitation minus evaporation generated by the mean flow, but shifts in storm-track location and intensity help to explain regional details of the precipitation anomaly pattern. The extreme seasonal precipitation anomalies that occurred during the two winters with the most positive (1988/89) and negative (2009/10) NAO indices are also explained by NAO-associated mean flow moisture convergence anomalies. 1852977 Article in Journal/Newspaper North Atlantic North Atlantic oscillation OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Climate 33 16 7179 7196 |
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 physical mechanisms whereby the mean and transient circulation anomalies associated with the North Atlantic Oscillation (NAO) drive winter mean precipitation anomalies across the North Atlantic Ocean, Europe, and the Mediterranean Sea region are investigated using the European Centre for Medium-Range Weather Forecasts interim reanalysis. A moisture budget decomposition is used to identify the contribution of the anomalies in evaporation, the mean flow, storm tracks and the role of moisture convergence and advection. Over the eastern North Atlantic, Europe, and the Mediterranean, precipitation anomalies are primarily driven by the mean flow anomalies with, for a positive NAO, anomalous moist advection causing enhanced precipitation in the northern British Isles and Scandinavia and anomalous mean flow moisture divergence causing drying over continental Europe and the Mediterranean region. Transient eddy moisture fluxes work primarily to oppose the anomalies in precipitation minus evaporation generated by the mean flow, but shifts in storm-track location and intensity help to explain regional details of the precipitation anomaly pattern. The extreme seasonal precipitation anomalies that occurred during the two winters with the most positive (1988/89) and negative (2009/10) NAO indices are also explained by NAO-associated mean flow moisture convergence anomalies. 1852977 |
author2 |
Seager, Richard (author) Liu, Haibo (author) Kushnir, Yochanan (author) Osborn, Timothy J. (author) Simpson, Isla R. (author) Kelley, Colin R. (author) Nakamura, Jennifer (author) |
format |
Article in Journal/Newspaper |
title |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
spellingShingle |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
title_short |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
title_full |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
title_fullStr |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
title_full_unstemmed |
Mechanisms of winter precipitation variability in the European-Mediterranean region associated with the North Atlantic Oscillation |
title_sort |
mechanisms of winter precipitation variability in the european-mediterranean region associated with the north atlantic oscillation |
publishDate |
2020 |
url |
https://doi.org/10.1175/JCLI-D-20-0011.1 |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_relation |
Journal of Climate--0894-8755--1520-0442 articles:23899 ark:/85065/d7377d1j doi:10.1175/JCLI-D-20-0011.1 |
op_rights |
Copyright 2020 American Meteorological Society (AMS). |
op_doi |
https://doi.org/10.1175/JCLI-D-20-0011.1 |
container_title |
Journal of Climate |
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33 |
container_issue |
16 |
container_start_page |
7179 |
op_container_end_page |
7196 |
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1797587708217917440 |