Q. Consider the following statements:

Statement I:
In January, in the Northern Hemisphere, the isotherms bend equatorward while crossing the landmasses, and poleward while crossing the oceans.

Statement II:
In January, the air over the oceans is warmer than that over the landmasses in the Northern Hemisphere.

Which one of the following is correct in respect of the above statements?
(a) Both Statement I and Statement II are correct and Statement II explains Statement I
(b) Both Statement I and Statement II are correct but Statement II does not explain Statement I
(c) Statement I is correct but Statement II is not correct
(d) Statement I is not correct but Statement II is correct

47. निम्नलिखित कथनों पर विचार कीजिए:
कथन I :
जनवरी में, उत्तरी गोलार्ध में, समताप रेखाएँ भूखण्डों से गुजरती हुई विषुवत् वृत्त की ओर मुड़ती हैं, जबकि महासागरों से गुजरती हुई ध्रुवों की ओर मुड़ती हैं।

कथन II :
जनवरी में, महासागरों के ऊपर की हवा, उत्तरी गोलार्ध के भूखण्डों के ऊपर की हवा से अधिक गर्म होती है।

उपर्युक्त कथनों के संदर्भ में, निम्नलिखित में से कौन-सा एक सही है?
(a) कथन I और कथन II दोनों सही है तथा कथन II, कथन I की व्याख्या करता है
(b) कथन I और कथन II दोनों सही हैं किन्तु कथन II, कथन I की व्याख्या नहीं करता है
(c) कथन I सही है किन्तु कथन II सही नहीं है
(d) कथन I सही नहीं है किन्तु कथन II सही है

Answer: A

Explanation:

Statement I is correct: In January the isotherms deviate to the poleward over the ocean and to the equatorward over the continent. This can be seen on the North Atlantic Ocean. The presence of warm ocean currents, Gulf Stream and North Atlantic drift, make the Northern Atlantic Ocean warmer and the isotherms bend towards the north. Over the land the temperature decreases sharply and the isotherms bend towards south in Europe. It is much pronounced in the Siberian plain. The mean January temperature along 60° E longitude is minus 20° C both at 80° N and 50 N latitudes. The mean monthly temperature for January is over 27° C, in equatorial oceans over 24° C in the tropics and 2° C - 0° C in the middle latitudes and –18° C to –48° C in the Eurasian continental interior.

Statement II is correct: The air over the oceans is warmer than the air over landmasses because water retains heat longer. Isotherms, which connect points of equal temperature, bend towards the poles when they cross the oceans.