HR: 17:20h
AN: A34A-05 INVITED     [Abstracts]
TI: Insights Into Ocean-Land-Atmosphere Interactions In The Tropical Atlantic From The Simulation Of The Boreal Summer African Monsoon In NSIPP1
AU: * Giannini, A
EM: alesall@iri.columbia.edu
AF: International Research Institute for climate prediction, Columbia University, PO Box 1000, Palisades, NY 10964-8000
AB: Analysis of a 9-member ensemble of simulations with a state-of-the-art atmospheric model, forced only by the observed record of sea surface temperature (SST) over 1930-2000, is presented to discuss some aspects of ocean-land-atmosphere interactions in the boreal summer African monsoon. Comparison of observations and model output reveals that the model is capable of capturing the dominant patterns of variability, and successful in separating them into one pattern representing the Gulf of Guinea, between the equator and 10N, and another representing the semi-arid Sahel, between 10N and 20N. While the former is found to connect rainfall over Africa to the Atlantic marine Intertropical Convergence Zone (ITCZ), and to be controlled by local, i.e. eastern equatorial Atlantic, SSTs, the latter is best characterized as a continental pattern, capturing the essence of the African summer monsoon, and displaying high sensitivity to SSTs in the global tropics.
DE: 3322 Land/atmosphere interactions
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4215 Climate and interannual variability (3309)
DE: 4231 Equatorial oceanography
DE: 1620 Climate dynamics (3309)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting