As we know that Indian Monsoon in highly unpredictable in nature because monsoon rains are affected by number of factors like the Inter Tropical Convergence Zone, El Nino, changes in pressure conditions over the Southern Oceans etc.India is located on tropical zone and the tropical systems have something called convection.These systems can grow very fast in a matter of hours.
Recenty, scientists from Pune’s Indian Institute of Tropical Meteorology (IITM) find that ocean mean temperature (OMT) that has better ability to predict this than the sea surface temperature(SST) which gives information only about the thin upper layer(few mm) of the ocean. Compared with SST which has 60% success rate of predicting the Indian summer monsoon, OMT has 80% success rate.
The reason why OMT performs better than SST is because OMT better represents the upper ocean thermal energy conditions. And the variations in the upper ocean thermal energy conditions are mainly responsible for the summer monsoon. When there is rapid heating or cooling, the temperature of the top ocean layer will be significantly different from the upper ocean thermal energy, resulting in misleading monsoon predictions.SST also exhibits large temperature fluctuations compared with OMT of the upper layer, leading to more noise that causes lower correlations with summer monsoon rainfall. The ocean mean temperature variations are more stable and consistent and have lower spatial and temporal spread. So OMT has better summer monsoon predictability than SST.
