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On the annual and seasonal patterns of rainfall fluctuations in sub‐saharan West Africa
Author(s) -
Adejuwon J. O.,
Balogun E. E.,
Adejuwon S. A.
Publication year - 1990
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.3370100806
Subject(s) - climatology , spectral analysis , trend analysis , series (stratigraphy) , environmental science , arid , geography , period (music) , seasonality , geology , mathematics , statistics , paleontology , physics , quantum mechanics , spectroscopy , acoustics
Monthly rainfall data for 16 stations in Nigeria were collected for the period 1922–1985. From this, the annual, the wet season, the onset, the peak, and the retreat rainfall data were derived. The patterns of fluctuations of rainfall were analysed therefrom. The series were first examined for trends and then for periodic fluctuations. Trend analysis revealed that a majority of the series exhibit negative trends, and in some cases the trends were significant. For all the series analysed, there is the general tendency towards increasing aridity. Spectral analysis indicates prominent periods of between 2‐and 8‐year cycles. Other periodicities observed include 16‐, 18‐, and 21‐year cycles.