With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct?
1. OMT is measured up to a depth of 26°C isotherm which is 129 meters 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 answer using the code given below:
Explanation
Statement 1 is incorrect: While Sea Surface Temperature (SST) only measures thermal conditions of the top few millimeters, Ocean Mean Temperature (OMT) is calculated down to the depth of the 26°C isotherm. Research by the Indian Institute of Tropical Meteorology (IITM) demonstrates that during January to March, the mean 26°C isotherm depth in the Southwestern Indian Ocean is approximately 59 metres (varying between 50 and 100 metres), not 129 metres.
Statement 2 is correct: Pre-monsoon OMT data collected between January and March provides a reliable measure of upper ocean heat energy, achieving an 80% success rate in predicting whether the upcoming Indian summer monsoon rainfall will deviate above or below the long-term mean.
Therefore, only statement 2 is correct — Option B.