1.OMT is measured up to a depth of 26°C isotherm which is 129 metres in the south-western Indian Ocean during January-March.
2.OMT collected during January-March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean.
Select the correct using the code given below:
Explanation
Ocean Mean Temperature (OMT) represents the thermal energy in the upper layer of the ocean. It is measured up to the 26°C isotherm, which represents the depth where water temperature is consistently 26°C. OMT is a more reliable indicator than Sea Surface Temperature (SST) for predicting the Indian monsoon rainfall, as it reflects the ocean’s thermal energy more comprehensively.
Statement 1 is incorrect: OMT is measured up to the 26°C isotherm. In the southwestern Indian Ocean during January-March, the depth of the 26°C isotherm is approximately 59 meters, not 129 meters.
Statement 2 is correct: OMT, especially during the January-March period (pre-monsoon season) has been found to be a useful indicator for forecasting the Indian Summer Monsoon rainfall. Warmer OMT in this period can suggest a stronger monsoon and potentially higher rainfall, while cooler OMT may indicate a weaker monsoon. This is because the ocean’s temperature influences the amount of moisture available for the monsoon winds. Studies by the Indian Institute of Tropical Meteorology (IITM) and other scientific bodies have shown a strong correlation between OMT and monsoon performance.