Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos
THE IMPACT OF THE NORTH ATLANTIC OSCILLATION ON THE EUROPEAN CLIMATE AND RIVER FLOW OF THREE MAJOR IBERIAN RIVERS – The North Atlantic Oscillation (NAO) is the most dominant mode of atmospheric circulation variability over the entire Northern Hemisphere (NH) and has recently been shown to be related...
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ftdoajarticles:oai:doaj.org/article:0f2c66fe5aa840c7afa29ddfcd66dd4e 2023-05-15T17:28:53+02:00 Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos Ricardo Trigo Timothy J. Osborn João Corte-Real 2002-06-01T00:00:00Z https://doaj.org/article/0f2c66fe5aa840c7afa29ddfcd66dd4e EN ES FR PT eng spa fre por CEG http://www.ceg.ul.pt/finisterra/numeros/2002-73/73_01.pdf https://doaj.org/toc/0430-5027 0430-5027 https://doaj.org/article/0f2c66fe5aa840c7afa29ddfcd66dd4e Finisterra - Revista Portuguesa de Geografia, Vol XXXVII, Iss 73, Pp 5-31 (2002) North Atlantic Oscillation Storm tracks Maximum and minimum temperatures Precipitation rate Precipitable water River flow regime Geography. Anthropology. Recreation G article 2002 ftdoajarticles 2022-12-31T06:16:34Z THE IMPACT OF THE NORTH ATLANTIC OSCILLATION ON THE EUROPEAN CLIMATE AND RIVER FLOW OF THREE MAJOR IBERIAN RIVERS – The North Atlantic Oscillation (NAO) is the most dominant mode of atmospheric circulation variability over the entire Northern Hemisphere (NH) and has recently been shown to be related to climate over large regions of the NH, in particular, over the European and North American continents. Here, a multivariable analysis of the influence ofthe NAO on the climate of the North Atlantic and European sectors is presented using the 40 year (1958-97) reanalysis data set from National Centres for Environmental Prediction. Using high and low NAO index composites, anomaly fields of climate variables are then interpreted based on physical mechanisms associated with the anomalous mean flow (characterised by the surface wind field) and theanomalous eddy activity (characterised by the surface vorticity and the 500hPa storm track fields). It is shown that NAO-related temperature patterns are mainly controlled by the advection of heat by the anomalous mean flow. However, asymmetries between minimum and maximum temperatures, and more significantly, between positive and negative phases of NAO imply the importance of a different mechanism, namely the modulation of short wave and long wave radiation by cloud cover variations associated with the NAO. Furthermore, NAO influence over two different precipitation-related variables, namely, precipitation rate and precipitable water display different patterns. Precipitable water is shown to be strongly related to the corresponding anomaly fields of temperature while precipitation rate appears to be controlled by the surface vorticity field and associated strength of the tropospheric synoptic activity. Finally, we have assessed the impact of the NAO on winter river flow regimes for several different Portuguese rivers, including the three main international Iberian rivers, the Douro (north), the Tagus (centre) and the Guadiana (south). Results show that the large inter-annual ... Article in Journal/Newspaper North Atlantic North Atlantic oscillation Directory of Open Access Journals: DOAJ Articles Winter River ENVELOPE(-113.003,-113.003,64.501,64.501) |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English Spanish French Portuguese |
topic |
North Atlantic Oscillation Storm tracks Maximum and minimum temperatures Precipitation rate Precipitable water River flow regime Geography. Anthropology. Recreation G |
spellingShingle |
North Atlantic Oscillation Storm tracks Maximum and minimum temperatures Precipitation rate Precipitable water River flow regime Geography. Anthropology. Recreation G Ricardo Trigo Timothy J. Osborn João Corte-Real Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
topic_facet |
North Atlantic Oscillation Storm tracks Maximum and minimum temperatures Precipitation rate Precipitable water River flow regime Geography. Anthropology. Recreation G |
description |
THE IMPACT OF THE NORTH ATLANTIC OSCILLATION ON THE EUROPEAN CLIMATE AND RIVER FLOW OF THREE MAJOR IBERIAN RIVERS – The North Atlantic Oscillation (NAO) is the most dominant mode of atmospheric circulation variability over the entire Northern Hemisphere (NH) and has recently been shown to be related to climate over large regions of the NH, in particular, over the European and North American continents. Here, a multivariable analysis of the influence ofthe NAO on the climate of the North Atlantic and European sectors is presented using the 40 year (1958-97) reanalysis data set from National Centres for Environmental Prediction. Using high and low NAO index composites, anomaly fields of climate variables are then interpreted based on physical mechanisms associated with the anomalous mean flow (characterised by the surface wind field) and theanomalous eddy activity (characterised by the surface vorticity and the 500hPa storm track fields). It is shown that NAO-related temperature patterns are mainly controlled by the advection of heat by the anomalous mean flow. However, asymmetries between minimum and maximum temperatures, and more significantly, between positive and negative phases of NAO imply the importance of a different mechanism, namely the modulation of short wave and long wave radiation by cloud cover variations associated with the NAO. Furthermore, NAO influence over two different precipitation-related variables, namely, precipitation rate and precipitable water display different patterns. Precipitable water is shown to be strongly related to the corresponding anomaly fields of temperature while precipitation rate appears to be controlled by the surface vorticity field and associated strength of the tropospheric synoptic activity. Finally, we have assessed the impact of the NAO on winter river flow regimes for several different Portuguese rivers, including the three main international Iberian rivers, the Douro (north), the Tagus (centre) and the Guadiana (south). Results show that the large inter-annual ... |
format |
Article in Journal/Newspaper |
author |
Ricardo Trigo Timothy J. Osborn João Corte-Real |
author_facet |
Ricardo Trigo Timothy J. Osborn João Corte-Real |
author_sort |
Ricardo Trigo |
title |
Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
title_short |
Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
title_full |
Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
title_fullStr |
Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
title_full_unstemmed |
Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
title_sort |
influência da oscilação do atlântico norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
publisher |
CEG |
publishDate |
2002 |
url |
https://doaj.org/article/0f2c66fe5aa840c7afa29ddfcd66dd4e |
long_lat |
ENVELOPE(-113.003,-113.003,64.501,64.501) |
geographic |
Winter River |
geographic_facet |
Winter River |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Finisterra - Revista Portuguesa de Geografia, Vol XXXVII, Iss 73, Pp 5-31 (2002) |
op_relation |
http://www.ceg.ul.pt/finisterra/numeros/2002-73/73_01.pdf https://doaj.org/toc/0430-5027 0430-5027 https://doaj.org/article/0f2c66fe5aa840c7afa29ddfcd66dd4e |
_version_ |
1766122016093503488 |