Coupled air-sea interactions in the tropical Indian Ocean environment

Raghavan Krishnan, K. V. Ramesh, B.K.Samala, G. Meyers, J.M.Slingo and M.J. Fennessy
Climate and Global Modelling Division
Indian Institute of Tropical Meteorology
Dr. Homi Bhabha Road, NCL Post
Pashan
Pune &Mac246; 411008
INDIA
Tel : +91-20-25893600
Email: krish@tropmet.res.in
krish0365@yahoo.com

Subsurface temperature measurements from Argo floats and XBT observations in the tropical Indian Ocean; satellite observations of sea surface height anomalies from TOPEX / POSEIDON and JASON; scatterometer winds from QuikSCAT and other atmospheric data products are analyzed in order to understand interactions between the monsoon circulation and the tropical Indian Ocean on the intra-seasonal time-scale. The findings reveal that ocean-atmosphere coupling is dominant on intra-seasonal time-scales. The ocean heat content and subsurface temperature anomalies in the equatorial Indian Ocean clearly bring out the role of monsoonal wind forcing on the intra-seasonal variations of the thermocline depth. Further, it is seen that the anomalies of ocean heat content influence the atmospheric winds and convection patterns on the intra-seasonal time-scale.