UPSC Prelims 2020 · Question 53 of 100
UPSC Prelims 2020 question on Ocean Mean Temperature
- ExamUPSC CSE
- Year2020
- PaperGeneral Studies Paper I
- SubjectGeography
- TopicOceanography
- DifficultyHard
- TypeStatement
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:
Show answer
Answer: B. 2 only
Verdict
Correct statement: 2 only → Option (b).
Analysis
The 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, which is measured up to a depth of 26 degree C isotherm, is more stable and consistent. Statement 1's specific figure of '129 meters in the south-western Indian Ocean during January-March' cannot be verified as correct from the material. Hence statement 1 is not correct as stated.
Statement by statement
Statement 1 – INCORRECT: Ocean heat content (OHC) and Ocean Mean Temperature (OMT) are important climatic parameters required for atmospheric and oceanic studies like cyclone and monsoon predictions and ocean heat transport estimations. Sea surface temperature (SST) is routinely used for predicting whether the total amount of rainfall that India receives during the monsoon season will be less or more than the long-term mean.
Statement 2 – CORRECT: Scientists from Pune's Indian Institute of Tropical Meteorology (IITM) find that ocean mean temperature (OMT) that has better ability to predict this than the sea surface temperature. Compared with SST which has 60% success rate of predicting the Indian summer monsoon, OMT has 80% success rate. OMT collected during January–March can thus be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean. Hence statement 2 is correct.