The influence of La Nina on African rainfall

✍ Scribed by S.E. Nicholson; J.C. Selato

• Book ID: 101324465
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 391 KB
• Volume: 20
• Category: Article
• ISSN: 0899-8418
• DOI: 10.1002/1097-0088(20001130)20:14<1761::aid-joc580>3.0.co;2-w

✦ Synopsis

This article examines the influence of La Nina/cold events on rainfall over the African continent, using a harmonic analysis method. As with El Nino, there is a general association between wet conditions continentally and cold temperatures in the Atlantic and Indian Oceans, and dry conditions in association with warm sea-surface temperatures (SSTs) in these oceans. La Nina appears to have the greatest influence on rainfall in southern Africa and wet episodes tend to occur throughout the subcontinent during the first few months of the post-La Nina year. There is a somewhat weaker tendency for below-normal rainfall in eastern equatorial Africa at this time. Our results provide further confirmation of an earlier conclusion that SSTs in the Atlantic and Indian Oceans are a primary influence on African rainfall. La Nina's influence tends to be exactly opposite that of El Nino: reduced rainfall over much of the continent in the first half of the episode, abnormally high rainfall in the second half. The documented El Nino/La Nina associations with African rainfall reflect the impact of these episodes on SSTs in the oceans.