महासागर औसत तापमान (Ocean Mean Temperature/OMT) के संदर्भ में, निम्नलिखित में से कौन-सा/से कथन सही है/हैं ?
- 1.OMT को 26°C समताप रेखा की गहराई तक मापा जाता है जो जनवरी – मार्च में हिन्द महासागर के दक्षिण-पश्चिम में 129 मीटर पर होती है ।
- 2.OMT, जो जनवरी – मार्च में एकत्रित किया जाता है उसे यह निर्धारित करने के लिए प्रयोग किया जा सकता है कि मानसून में वर्षा की मात्रा एक निश्चित दीर्घकालीन औसत वर्षा से कम होगी या अधिक ।
नीचे दिए गए कूट का प्रयोग कर सही उत्तर चुनिए :
Read this question in English
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:
(a) 1 only · (b) 2 only · (c) Both 1 and 2 · (d) Neither 1 nor 2
उत्तर और व्याख्या · explanation in English
Answer: (b) केवल 2
Statement 2 is right and statement 1 is wrong. OMT (the average temperature of the ocean from the surface down to the 26°C isotherm) in the south-western Indian Ocean during January–March helps predict whether the coming monsoon rainfall will be above or below average, but the 26°C isotherm there lies at about 59 m, not 129 m.
- ✗ 1. OMT is the mean temperature of the layer from the surface down to the 26°C isotherm, which is the first half of the statement. But the January–March climatic mean depth of that isotherm in the south-western Indian Ocean is about 59 m, not 129 m.
- ✓ 2. The January–March south-western Indian Ocean OMT is a better qualitative predictor of Indian summer monsoon rainfall than sea surface temperature; it correctly signals above-average or below-average rain about 80% of the time, against 60% for SST.
Remember · OMT = mean temperature from the surface to the 26°C isotherm; south-western Indian Ocean OMT in January–March forecasts monsoon rain (isotherm depth about 59 m there).
Sources
- Venugopal et al., 'Statistical Evidence for the Role of Southwestern Indian Ocean Heat Content in the Indian Summer Monsoon Rainfall', Scientific Reports 8:12092 (2018), open-access copy on PubMed Central (NIH) ↗ “Here, we show that the southwestern Indian OMT down to the depth of the 26 °C isotherm during January–March is a better qualitative predictor of the ISMR than SST. … The January–March climatic mean D 26 is 59 m and the corresponding OHC is 50 kJ cm −2 in this region.”
Question and answer: UPSC's official GS Paper I (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·