Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram
Extremal dependence or independence may occur among the components of univariate or bivariate random vectors. Assessing which asymptotic regime occurs and also its extent are crucial tasks when such vectors are used as statistical models for risk assessment in the field of Climatology under climate...
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ftmdpi:oai:mdpi.com:/2073-4441/12/11/2989/ 2023-08-20T04:08:14+02:00 Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram Luis Angel Espinosa Maria Manuela Portela Rui Rodrigues agris 2020-10-25 application/pdf https://doi.org/10.3390/w12112989 EN eng Multidisciplinary Digital Publishing Institute Hydrology https://dx.doi.org/10.3390/w12112989 https://creativecommons.org/licenses/by/4.0/ Water; Volume 12; Issue 11; Pages: 2989 extremal dependence climate change extremogram cross-extremogram extreme rainfall NAOI small island Madeira Island Text 2020 ftmdpi https://doi.org/10.3390/w12112989 2023-08-01T00:20:45Z Extremal dependence or independence may occur among the components of univariate or bivariate random vectors. Assessing which asymptotic regime occurs and also its extent are crucial tasks when such vectors are used as statistical models for risk assessment in the field of Climatology under climate change conditions. Motivated by the poor resolution of current global climate models in North Atlantic Small Islands, the extremal dependence between a North Atlantic Oscillation index (NAOI) and rainfall was considered at multi-year dominance of negative and positive NAOI, i.e., −NAOI and +NAOI dominance subperiods, respectively. The datasets used (from 1948–2017) were daily NAOI, and three daily weighted regionalised rainfall series computed based on factor analysis and the Voronoi polygons method from 40 rain gauges in the small island of Madeira (∼740 km2), Portugal. The extremogram technique was applied for measuring the extremal dependence within the NAOI univariate series. The cross-extremogram determined the dependence between the upper tail of the weighted regionalised rainfalls, and the upper and lower tails of daily NAOI. Throughout the 70-year period, the results suggest systematic evidence of statistical dependence over Madeira between exceptionally −NAOI records and extreme rainfalls, which is stronger in the −NAOI dominance subperiods. The extremal dependence for +NAOI records is only significant in recent years, however, with a still unclear +NAOI dominance. Text North Atlantic North Atlantic oscillation MDPI Open Access Publishing Water 12 11 2989 |
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MDPI Open Access Publishing |
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ftmdpi |
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English |
topic |
extremal dependence climate change extremogram cross-extremogram extreme rainfall NAOI small island Madeira Island |
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extremal dependence climate change extremogram cross-extremogram extreme rainfall NAOI small island Madeira Island Luis Angel Espinosa Maria Manuela Portela Rui Rodrigues Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
topic_facet |
extremal dependence climate change extremogram cross-extremogram extreme rainfall NAOI small island Madeira Island |
description |
Extremal dependence or independence may occur among the components of univariate or bivariate random vectors. Assessing which asymptotic regime occurs and also its extent are crucial tasks when such vectors are used as statistical models for risk assessment in the field of Climatology under climate change conditions. Motivated by the poor resolution of current global climate models in North Atlantic Small Islands, the extremal dependence between a North Atlantic Oscillation index (NAOI) and rainfall was considered at multi-year dominance of negative and positive NAOI, i.e., −NAOI and +NAOI dominance subperiods, respectively. The datasets used (from 1948–2017) were daily NAOI, and three daily weighted regionalised rainfall series computed based on factor analysis and the Voronoi polygons method from 40 rain gauges in the small island of Madeira (∼740 km2), Portugal. The extremogram technique was applied for measuring the extremal dependence within the NAOI univariate series. The cross-extremogram determined the dependence between the upper tail of the weighted regionalised rainfalls, and the upper and lower tails of daily NAOI. Throughout the 70-year period, the results suggest systematic evidence of statistical dependence over Madeira between exceptionally −NAOI records and extreme rainfalls, which is stronger in the −NAOI dominance subperiods. The extremal dependence for +NAOI records is only significant in recent years, however, with a still unclear +NAOI dominance. |
format |
Text |
author |
Luis Angel Espinosa Maria Manuela Portela Rui Rodrigues |
author_facet |
Luis Angel Espinosa Maria Manuela Portela Rui Rodrigues |
author_sort |
Luis Angel Espinosa |
title |
Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
title_short |
Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
title_full |
Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
title_fullStr |
Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
title_full_unstemmed |
Significant Extremal Dependence of a Daily North Atlantic Oscillation Index (NAOI) and Weighted Regionalised Rainfall in a Small Island Using the Extremogram |
title_sort |
significant extremal dependence of a daily north atlantic oscillation index (naoi) and weighted regionalised rainfall in a small island using the extremogram |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2020 |
url |
https://doi.org/10.3390/w12112989 |
op_coverage |
agris |
genre |
North Atlantic North Atlantic oscillation |
genre_facet |
North Atlantic North Atlantic oscillation |
op_source |
Water; Volume 12; Issue 11; Pages: 2989 |
op_relation |
Hydrology https://dx.doi.org/10.3390/w12112989 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/w12112989 |
container_title |
Water |
container_volume |
12 |
container_issue |
11 |
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2989 |
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1774720395461525504 |