Which of the following is/are NOT a cold ocean current ?
1. Agulhas current
2. Brazil current
3. Humboldt current
4. California current
Select the correct answer from the code given below :
Code :

Question

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Correct — D, 1 and 2: the Agulhas Current and the Brazil Current are the two that are NOT cold. Both are warm currents, and they are warm for the same structural reason. Each is a western boundary current — it runs along the western edge of an ocean basin, which is the eastern coast of a continent — and western boundary currents carry tropical water polewards. The Agulhas is the warm current of the south-west Indian Ocean, sweeping south down the coasts of Mozambique and South Africa before turning back on itself in the celebrated Agulhas retroflection. The Brazil Current is its South Atlantic counterpart, running south along the Brazilian coast until it collides with the cold Falkland or Malvinas Current in the confluence off Argentina, one of the sharpest temperature fronts in any ocean. The other two in the list are genuinely cold. The Humboldt Current, also called the Peru Current, flows equatorward up the coasts of Chile and Peru and drives the upwelling that feeds one of the world's largest fisheries; the California Current flows equatorward down the coast of the western United States. Both are eastern boundary currents, and eastern boundary currents are cold, broad and slow, drawing water from higher latitudes and pulling cold water up from below along the coast. So the two that are not cold are 1 and 2, and on this paper that is option (d).

Why the other options are wrong — (a) Half right and half wrong. The Agulhas does belong in the answer, since it is warm, but the Humboldt Current does not: it is one of the coldest and most important cold currents on Earth, an equatorward eastern boundary current whose upwelled water supports the Peruvian anchoveta fishery and helps keep the Atacama desert dry. Including it in a list of currents that are not cold reverses one of the most heavily taught facts in physical geography.  (b) The same mistake with the other warm current. The Brazil Current is correctly identified as not cold, but the Humboldt Current is cold — a candidate who marks this has recognised one western boundary current and then failed to notice that the second name in the option is an eastern boundary current on the opposite side of South America. The Brazil Current runs down the Atlantic side and is warm; the Humboldt runs up the Pacific side and is cold. They are almost a matched pair for teaching the contrast.  (c) This is the trap the question was written for, and it is the answer to the opposite question. Humboldt and California are exactly the two cold currents in the list, so a candidate who identifies them correctly and then forgets that the question asks which are NOT cold will mark this option with complete confidence. It is worth pausing over: the geography here is perfectly understood and the mark is still lost, purely on the negation.

Concept: Surface ocean currents are driven mainly by the prevailing winds and organised by the Coriolis effect into great rotating gyres — clockwise in the northern hemisphere, anticlockwise in the southern. Because a gyre turns, its two flanks behave differently. On the western side of an ocean basin, which is the east coast of a continent, water is pushed away from the equator, so western boundary currents are warm; they are also narrow, deep and fast, the Gulf Stream, Kuroshio, Brazil, Agulhas and East Australian currents being the standard examples. On the eastern side of a basin, which is the west coast of a continent, water returns towards the equator from higher latitudes, so eastern boundary currents are cold; they are broad, shallow and slow, and offshore-directed wind stress along these coasts drives upwelling that brings still colder, nutrient-rich water to the surface. The Canary, Benguela, California and Humboldt currents are the classic four. That single rule of thumb answers most exam questions of this type without any memorisation of individual names.

State PCS 2025 Q133 — Geography PYQ with Answer

State PCS 2025 Q133 — Geography PYQ with Answer