Standardized rainfall indices for the West and Central Sahel, and the Guinea Coast

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Autori principali: Fink, Andreas H, Schrage, Jon M, Kotthaus, Simone
Natura: Dataset Open Access
Lingua:en
Pubblicazione: PANGAEA 2010
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author Fink, Andreas H
Schrage, Jon M
Kotthaus, Simone
author_facet Fink, Andreas H
Schrage, Jon M
Kotthaus, Simone
collection Datos científicos de ciencias marinas y ambientales
contents For years, various indices of seasonal West African precipitation have served as useful predictors of the overall tropical cyclone activity in the Atlantic Ocean. Since the mid-1990s, the correlation unexpectedly deteriorated. In the present study, statistical techniques are developed to describe the nonstationary nature of the correlations between annual measures of Atlantic tropical cyclone activity and three selected West African precipitation indices (namely, western Sahelian precipitation in June-September, central Sahelian precipitation in June-September, and Guinean coastal precipitation in the preceding year's August-November period). The correlations between these parameters are found to vary over the period from 1921 to 2007 on a range of time scales. Additionally, considerable year-to-year variability in the strength of these correlations is documented by selecting subsamples of years with respect to various meteorological factors. Broadly, in years when the environment in the main development region is generally favorable for enhanced tropical cyclogenesis (e.g., when sea surface temperatures are high, when there is relatively little wind shear through the depth of the troposphere, or when the relative vorticity in the midtroposphere is anomalously high), the correlations between indices of West African monsoon precipitation and Atlantic tropical cyclone activity are considerably weaker than in years when the overall conditions in the region are less conducive. Other more remote climate parameters, such as the phase of the Southern Oscillation, are less effective at modulating the nature of these interactions.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_816398
institution PANGAEA
language en
publishDate 2010
publisher PANGAEA
record_format pangaea
spellingShingle Standardized rainfall indices for the West and Central Sahel, and the Guinea Coast
Fink, Andreas H
Schrage, Jon M
Kotthaus, Simone
Central_Sahel; Central Sahel, Africa; DATE/TIME; Event label; Global Change and the Hydrological Cycle; GLOWA; Guinea_Coast; Guinea Coast, Africa; IMPETUS; Index; Number of stations; OBSE; Observation; West_Sahel; West Sahel, Africa
For years, various indices of seasonal West African precipitation have served as useful predictors of the overall tropical cyclone activity in the Atlantic Ocean. Since the mid-1990s, the correlation unexpectedly deteriorated. In the present study, statistical techniques are developed to describe the nonstationary nature of the correlations between annual measures of Atlantic tropical cyclone activity and three selected West African precipitation indices (namely, western Sahelian precipitation in June-September, central Sahelian precipitation in June-September, and Guinean coastal precipitation in the preceding year's August-November period). The correlations between these parameters are found to vary over the period from 1921 to 2007 on a range of time scales. Additionally, considerable year-to-year variability in the strength of these correlations is documented by selecting subsamples of years with respect to various meteorological factors. Broadly, in years when the environment in the main development region is generally favorable for enhanced tropical cyclogenesis (e.g., when sea surface temperatures are high, when there is relatively little wind shear through the depth of the troposphere, or when the relative vorticity in the midtroposphere is anomalously high), the correlations between indices of West African monsoon precipitation and Atlantic tropical cyclone activity are considerably weaker than in years when the overall conditions in the region are less conducive. Other more remote climate parameters, such as the phase of the Southern Oscillation, are less effective at modulating the nature of these interactions.
title Standardized rainfall indices for the West and Central Sahel, and the Guinea Coast
topic Central_Sahel; Central Sahel, Africa; DATE/TIME; Event label; Global Change and the Hydrological Cycle; GLOWA; Guinea_Coast; Guinea Coast, Africa; IMPETUS; Index; Number of stations; OBSE; Observation; West_Sahel; West Sahel, Africa
url https://doi.org/10.1594/PANGAEA.816398