Mean Circulation and Water Masses and Their Variability in the Western Tropical Pacific and Eastern Tropical Indian Ocean

Abstract:

Circulation patterns in both the western tropical Pacific and eastern tropical Indian Ocean are examined in the context of upper ocean streamfunction estimates derived from Argo floats and other historical observations. The flow and water mass characteristics of the Pacific input to the Indonesian throughflow and the output in the Indian Ocean are compared and contrasted. It is shown that the upper ocean waters exiting Indonesia can be traced into the central Indian Ocean. The variability in the decadal-mean streamfunction is considerable, especially in the western Pacific warm pool. The water mass differences across Indonesia highlight the importance of this region in determining the upper ocean properties of the eastern Indian Ocean and the need for better direct observations of the processes responsible for these transformations.