Tropical Indian Ocean Surface and Subsurface Temperature Fluctuations in a Climate Change Scenario

Muni Krishna K

doi:10.4172/2329-6755.1000152

Abstract

Tropical Indian Ocean temperature plays a vital on Indian monsoon system and also cyclone genesis. The feature and evolution mechanisms of the tropical Indian Ocean temperature between pre warming and warming period and also during Indian Ocean Dipole (IOD) events that co-occurred with El Nino are studied using Simple Ocean Data Assimilation (SODA) data set. The southeastern Arabian Sea, Western Arabian Sea and Seychelles Chaogos Thermocline Ridge regions subsurface temperature anomalies are cooled and the southern gyre, south Bay of Bengal, off java regions show warming trend from surface to subsurface. During the positive IOD with co-occurred El Nino years in a climate change period (1970-2008) surface warm temperatures are extended from the Sumatra region to off the African coast in pre-monsoon season. But the subsurface temperature shows different pattern, the warming is more in the central Arabian Sea and south Bay of Bengal (BoB) area.

Highlights

The oceans cover about 71% of the Earth’s surface and have an average depth of 3.7 km
We examine the intra annual variability of the sea surface temperature (SST) anomaly over the Tropical Indian Ocean based on Simple Ocean Data Assimilation (SODA) temperature data of 0.25° x 0.4° latitude longitude grid derived from the Asia Pacific Data Research Centre
During June, when the sun is in the extreme position in the northern hemisphere and the monsoonal wind is strong over the tropical Indian Ocean, the SST anomaly of southeast Arabian Sea (SEAS) has decreased significantly, whereas the BOB is still remaining relatively warm, in particular north of 10°N

Summary

Introduction

The oceans cover about 71% of the Earth’s surface and have an average depth of 3.7 km. The western Arabian Sea is cooler than the January pattern, and the warm SST anomaly along the east coast of India is significantly reduced. During June, when the sun is in the extreme position in the northern hemisphere and the monsoonal wind is strong over the tropical Indian Ocean, the SST anomaly of SEAS has decreased significantly, whereas the BOB is still remaining relatively warm, in particular north of 10°N.

Results

Conclusion