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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ftdatacite:10.18055/finis1606 2023-05-15T17:31:02+02:00 Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos Trigo, Ricardo Osborn, Timothy Corte-Real, João 2012 https://dx.doi.org/10.18055/finis1606 https://revistas.rcaap.pt/finisterra/article/view/1606 pt por Finisterra Este trabalho está licenciado com uma Licença Creative Commons - Atribuição-NãoComercial-SemDerivações 4.0 Internacional. http://creativecommons.org/licenses/by-nc-nd/4.0 CC-BY-NC-ND Text Article article-journal ScholarlyArticle 2012 ftdatacite https://doi.org/10.18055/finis1606 2021-11-05T12:55:41Z 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 variability of flow of these three rivers is largely modulated by the NAO. Such modulation, associated with the recent positive trend of the NAO index, might implicate a significant decrease of the available flow. This reduction can representan important hazard for the Portuguese economy due to its negative impact in agricultural yield and hydroelectric power production. : Finisterra, vol. 37 n.º 73 (2002) Text North Atlantic North Atlantic oscillation DataCite Metadata Store (German National Library of Science and Technology) Winter River ENVELOPE(-113.003,-113.003,64.501,64.501) Finisterra 37 73 |
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Open Polar |
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DataCite Metadata Store (German National Library of Science and Technology) |
op_collection_id |
ftdatacite |
language |
Portuguese |
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 variability of flow of these three rivers is largely modulated by the NAO. Such modulation, associated with the recent positive trend of the NAO index, might implicate a significant decrease of the available flow. This reduction can representan important hazard for the Portuguese economy due to its negative impact in agricultural yield and hydroelectric power production. : Finisterra, vol. 37 n.º 73 (2002) |
format |
Text |
author |
Trigo, Ricardo Osborn, Timothy Corte-Real, João |
spellingShingle |
Trigo, Ricardo Osborn, Timothy Corte-Real, João Influência da Oscilação do Atlântico Norte no clima do continente europeu e no caudal dos rios ibéricos atlânticos |
author_facet |
Trigo, Ricardo Osborn, Timothy Corte-Real, João |
author_sort |
Trigo, Ricardo |
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 |
Finisterra |
publishDate |
2012 |
url |
https://dx.doi.org/10.18055/finis1606 https://revistas.rcaap.pt/finisterra/article/view/1606 |
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_rights |
Este trabalho está licenciado com uma Licença Creative Commons - Atribuição-NãoComercial-SemDerivações 4.0 Internacional. http://creativecommons.org/licenses/by-nc-nd/4.0 |
op_rightsnorm |
CC-BY-NC-ND |
op_doi |
https://doi.org/10.18055/finis1606 |
container_title |
Finisterra |
container_volume |
37 |
container_issue |
73 |
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1766128333490225152 |