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:

QUESTION

Hard

Indian Geography

Prelims 2020

With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct?

OMT is measured up to a depth of 26°C isotherm which is 129 meters in the south-western Indian Ocean during January-March.
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:

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Explanation

Statement 1 is Incorrect: While OMT is measured up to the depth of the 26°C isotherm ( $D_{26}$ ), this depth is approximately 59 meters in the south-western Indian Ocean during January-March, not 129 meters. Statement 2 is Correct: OMT is a more stable and reliable indicator of the upper ocean's heat content than Sea Surface Temperature (SST). Research by the Indian Institute of Tropical Meteorology (IITM) has shown that OMT data collected from January to March can be used to predict whether the Indian Summer Monsoon Rainfall (ISMR) will be above or below the long-term mean with greater accuracy than SST.