West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic

Based on daily precipitation from the Global Precipitation Climatology Project (GPCP) data during April–October of the 1997–2014 period, the daily extreme rainfall trends and variability over West Africa are characterized using 90th-percentile threshold at each grid point. The contribution of the ex...

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Main Authors: S. Ta, K. Y. Kouadio, K. E. Ali, E. Toualy, A. Aman, F. Yoroba
Format: Article
Language:English
Published: Wiley 2016-01-01
Series:Advances in Meteorology
Online Access:http://dx.doi.org/10.1155/2016/1940456
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author S. Ta
K. Y. Kouadio
K. E. Ali
E. Toualy
A. Aman
F. Yoroba
author_facet S. Ta
K. Y. Kouadio
K. E. Ali
E. Toualy
A. Aman
F. Yoroba
author_sort S. Ta
collection DOAJ
description Based on daily precipitation from the Global Precipitation Climatology Project (GPCP) data during April–October of the 1997–2014 period, the daily extreme rainfall trends and variability over West Africa are characterized using 90th-percentile threshold at each grid point. The contribution of the extreme rainfall amount reaches ~50–90% in the northern region while it is ~30–50% in the south. The yearly cumulated extreme rainfall amount indicates significant and negative trends in the 6°N–12°N; 6°N–12°N; 17°W–10°W and 4°N–7°N; 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E domains, while the number of days exhibits nonsignificant trends over West Africa. The empirical orthogonal functions performed on the standardized anomalies show four variability modes that include all West Africa with a focus on the Sahelian region, the eastern region including the south of Nigeria, the western part including Guinea, Sierra Leone, Liberia, and Guinea-Bissau, and finally a small region at the coast of Ghana and Togo. These four modes are influenced differently by the large-scale ocean surface and atmospheric conditions in the tropical Atlantic. The results are applicable in planning the risks associated with these climate hazards, particularly on water resource management and civil defense.
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spelling doaj-art-66b488e724854443b34c0a841b4091022025-08-20T02:23:41ZengWileyAdvances in Meteorology1687-93091687-93172016-01-01201610.1155/2016/19404561940456West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical AtlanticS. Ta0K. Y. Kouadio1K. E. Ali2E. Toualy3A. Aman4F. Yoroba5Laboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireLaboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireLaboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireLaboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireLaboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireLaboratory of Atmospheric Physics and Fluid Mechanics, University FHB of Cocody-Abidjan, 22 BP 582, Abidjan 22, Côte d’IvoireBased on daily precipitation from the Global Precipitation Climatology Project (GPCP) data during April–October of the 1997–2014 period, the daily extreme rainfall trends and variability over West Africa are characterized using 90th-percentile threshold at each grid point. The contribution of the extreme rainfall amount reaches ~50–90% in the northern region while it is ~30–50% in the south. The yearly cumulated extreme rainfall amount indicates significant and negative trends in the 6°N–12°N; 6°N–12°N; 17°W–10°W and 4°N–7°N; 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E 4°N–7°N; 6°E–10°E domains, while the number of days exhibits nonsignificant trends over West Africa. The empirical orthogonal functions performed on the standardized anomalies show four variability modes that include all West Africa with a focus on the Sahelian region, the eastern region including the south of Nigeria, the western part including Guinea, Sierra Leone, Liberia, and Guinea-Bissau, and finally a small region at the coast of Ghana and Togo. These four modes are influenced differently by the large-scale ocean surface and atmospheric conditions in the tropical Atlantic. The results are applicable in planning the risks associated with these climate hazards, particularly on water resource management and civil defense.http://dx.doi.org/10.1155/2016/1940456
spellingShingle S. Ta
K. Y. Kouadio
K. E. Ali
E. Toualy
A. Aman
F. Yoroba
West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
Advances in Meteorology
title West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
title_full West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
title_fullStr West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
title_full_unstemmed West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
title_short West Africa Extreme Rainfall Events and Large-Scale Ocean Surface and Atmospheric Conditions in the Tropical Atlantic
title_sort west africa extreme rainfall events and large scale ocean surface and atmospheric conditions in the tropical atlantic
url http://dx.doi.org/10.1155/2016/1940456
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