With reference to Ocean Mean Temperature (OMT), which of the following

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 :

1 only
2 only
Both 1 and 2
Neither 1 nor 2
This question was previously asked in
UPSC IAS – 2020
The correct option is B, as statement 2 is correct regarding the use of OMT in monsoon prediction, while statement 1 contains specific details that may not be universally accurate or precisely phrased.
Ocean Mean Temperature (OMT) represents the average temperature of the upper ocean layer, typically down to the depth where the temperature is 26°C. This measure reflects the heat content of the upper ocean and is considered a better predictor of the Indian Summer Monsoon than Sea Surface Temperature (SST) alone.
1. **Depth and Measurement:** OMT is measured up to the depth of the 26°C isotherm. The depth of the 26°C isotherm is not fixed at 129 meters but varies geographically and seasonally. While it might be around 129 meters in the specific region (south-western Indian Ocean) and time (January-March) mentioned, stating it as a fixed depth “which is 129 meters” can be misleading, as the OMT is defined by the varying depth of the isotherm, not a fixed depth. Therefore, this statement is likely inaccurate or too specific/poorly phrased for a general description.
2. **Monsoon Prediction:** Studies have shown a strong correlation between the Ocean Mean Temperature in the southeastern equatorial Indian Ocean and the southwestern Bay of Bengal during the pre-monsoon period (January-March or April-May) and the subsequent Indian Summer Monsoon rainfall. Higher OMT in this region is generally associated with a better monsoon. This statement is correct.