UPSC Mains 2015 · GS I · Q14 · 12.5 marks · 200 words

Explain the factors responsible for the origin of ocean currents. How do they influence regional climates, fishing and navigation ?

हिन्दी में

महासागरी धाराओं की उत्पत्ति के उत्तरदायी कारकों को स्पष्ट कीजिए। वे प्रादेशिक जलवायुओं, समुद्री जीवन तथा नौचालन को किस प्रकार प्रभावित करती हैं ?

Oceanography Climatology

How a topper answered the closest question

Toppers wrote this one in a test series: “What are the major controlling forces of global ocean currents? Illustrate how ocean currents influence marine fisheries and coastal climate.”

AakritiAIR 93 · CSE 2025 · 176 wordsTheir whole copy

Opening · a definition

Ocean currents are narrow bands of fast moving ocean water that redistribute the nutrients, heat & carbon.

Body · points and prose

Diagram

Types of ocean currents (1) HOT eg. Kyoshio, gulf stream (2) COLD eg. oyoshio, canary, labrador

Diagram

[Map showing global ocean currents with labels: North Pacific Drift, California, Labrador, Gulf Stream, North Atlantic Drift, Norway, Canary, Oyoshio, Kyoshio, Chile-Peru, Humbolt, East Australian, West Australian] fig: global ocean currents

Factors influencing

1.) Heat differential → eg. Equator - warm water expands → moves towards upper latitudes eg. Kyoshio

2.) Contour of continents eg. Brazillian current

3.) Regional winds eg. Indian ocean currents change with monsoon winds

4.) Earth's rotation eg. Equitorial currents.

5.) Land & water distribution eg. Antarctic circumpolar current - continuous.

Influence of ocean currents

(A) On coastal climate

(a) Desert formation eg. Namibia due to Benguela current (Dessicating effect)

(b) Heavy rainfall eg. British type climate due to effect of warm gulf stream.

(B) On Marine fisheries

(a) Dense fish stock in areas of warm-cold current mixing eg. near Japan

Diagram

[Arrow pointing to box labelled KUROSHIO]

(b) Areas of upwelling → nutrient increase → more fish. eg. coasts of south americas.

Close · a way forward

ocean currents are a life giving & regulating force in oceans. Its effects pattern must be carefully studied especially as climate change is weakening the Atlantic Meridional Ocean Current

How toppers approach this question, and more on its topic: open the question.

Toppers’ answers to other close questions

Source: UPSC, Civil Services (Main) Examination 2015, General Studies Paper I, Q14. The paper on upsc.gov.in. Themes and links to toppers’ answers are by UPSC Grade, not by UPSC.