Tropical-midlatitude interactions in the Indian and Pacific sectors of the Southern Hemisphere

Observations and three General Circulation Model (GCM) simulations are analyzed to study interannual processes and interactions involved in the tropical Indian and Pacific sectors and higher southern latitudes. Major features involving the observed eastward progression of the tropical convective maximum from the Indian monsoon in northern summer to the Australian monsoon and Pacific in southern summer are represented in all three model simulations. This suggests that the distribution of land and sea accounts for the observed seasonal position of the convective maximum in these regions. However, the South Pacific convergence zone (SPCZ) is not present at any time of year in the slab-ocean models due to the anomalously warm sea-surface temperatures simulated in the equatorial Pacific. -from Author