UPSC Prelims 2020 Question:

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 using the code given below:

Explanation:

• According to research by Indian Institute of Tropical Meteorology (IITM), Pune, Ocean Mean Temperature (OMT) is more effective in predicting weather patterns than Sea Surface Temperature (SST). It was found that in comparision to SST which has 60% success rate of predicting the Indian summer monsoon, OMT has 80% success rate.
  
  
• SST is restricted to a few millimetres of the top ocean layer and is largely influenced by strong winds, evaporation, or thick clouds. In contrast, OMT,  is measured up to a depth of 59 metres at 26°C isotherm in the Southwestern Indian Ocean. It is more stable and consistent, and the spatial spread is also less. So, statement 1 is not correct.
  
  
• OMT is an indicator of monsoon rainfall. OMT is analysed by measuring the ocean thermal energy during the period from January to March. Southwest monsoon sets in around June 1 each year in Kerala. So, statement 2 is correct.
  
  

Therefore, option (2) is the correct answer.

Subject: Geography | Oceanography