What are the factors affecting the surface temperature of oceans? Discuss the impact of difference in sea surface temperatures of the tropical western and eastern Indian Ocean upon Climate of India.
Factors affecting surface temperature of oceans are:
Latitude– Surface temperature of ocean water is highest near equator and decreases as one moves towards poles.
Prevailing winds– Coriolis force causes the trade winds to move from east to west on both sides of the equator. Winds carry with them the warm surface water from eastern sides of the oceans to western side. Due to this the surface temperature of oceans on the eastern parts is much lower than that on western parts.
Salinity– Saline water absorbs more heat than fresh water.
Adjacent land masses– Temperature of enclosed seas rises and falls quickly due to heat transfer from land to seas and vice versa.
Effects of temperature difference in sea surface temperatures of the tropical western and eastern Indian Ocean on India
The changes in the sea surface temperatures of the tropical western and eastern Indian Ocean are known as the Indian Ocean Dipole or IOD. Indian Ocean Dipole exhibits two phases: positive phase and negative phase. The positive phase represents cooler than normal eastern Indian Ocean and anomalous warming of western basin of Indian Ocean. This phase is favourable for Indian monsoon. The opposite phenomenon is negative phase of IOD. It is characterised by anomalous warming of the sea surface temperature in the eastern Indian Ocean and cooler than normal in the western Indian Ocean. This phase is unfavourable for Indian monsoon. (232 words)