The rainfall mean state and variability of the tropical Southern Hemisphere are strongly affected by the Tropical Convergence Zones. Unlike the South Pacific and South Atlantic, the topography of Madagascar prevents, through the Mozambique Channel Trough, the direct transport of moisture from the Indian Ocean toward southern Africa that feeds the South Indian Ocean Convergence Zone (SICZ). Numerical experiments using regional climate models reveal that a flatter than actual topography over Madagascar results in a strengthening of the SICZ through anomalously high easterly moisture fluxes transported from the Indian Ocean and the Mozambique Channel. These in turn trigger a significant increase in precipitation over southern Africa extending from Mozambique to Angola and a decrease in rainfall over Madagascar. These results have important implications for the improvement of the representation of African rainfall mean state and variability, which has been identified as a persisting issue in different generations of state-of-the-art climate models.

Barimalala, R., Desbiolles, F., Blamey, R., Reason, C. (2018). Madagascar Influence on the South Indian Ocean Convergence Zone, the Mozambique Channel Trough and Southern African Rainfall. GEOPHYSICAL RESEARCH LETTERS, 45(20), 11380-11389 [10.1029/2018GL079964].

Madagascar Influence on the South Indian Ocean Convergence Zone, the Mozambique Channel Trough and Southern African Rainfall

Desbiolles, F;
2018

Abstract

The rainfall mean state and variability of the tropical Southern Hemisphere are strongly affected by the Tropical Convergence Zones. Unlike the South Pacific and South Atlantic, the topography of Madagascar prevents, through the Mozambique Channel Trough, the direct transport of moisture from the Indian Ocean toward southern Africa that feeds the South Indian Ocean Convergence Zone (SICZ). Numerical experiments using regional climate models reveal that a flatter than actual topography over Madagascar results in a strengthening of the SICZ through anomalously high easterly moisture fluxes transported from the Indian Ocean and the Mozambique Channel. These in turn trigger a significant increase in precipitation over southern Africa extending from Mozambique to Angola and a decrease in rainfall over Madagascar. These results have important implications for the improvement of the representation of African rainfall mean state and variability, which has been identified as a persisting issue in different generations of state-of-the-art climate models.
Articolo in rivista - Articolo scientifico
Mozambique Channel Trough; regional rainfall; South Indian Ocean Convergence Zone; topography;
English
10-ott-2018
2018
45
20
11380
11389
none
Barimalala, R., Desbiolles, F., Blamey, R., Reason, C. (2018). Madagascar Influence on the South Indian Ocean Convergence Zone, the Mozambique Channel Trough and Southern African Rainfall. GEOPHYSICAL RESEARCH LETTERS, 45(20), 11380-11389 [10.1029/2018GL079964].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/408177
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