Create a detailed note explaining the various

factors that affect ocean currents around the

world. Factors like wind, coriolis force,
temperature, salinity, density and physiography
and others. Give all the major and minor currents
around the world and the factors affecting them.
Use tips and tricks to help me remember these
currents and their characteristics. NO
MNEMONICS.
Ocean currents: drivers, patterns, and all major currents
Direct answer: Ocean currents are set and steered by surface winds, Earth’s rotation (Coriolis),
horizontal pressure gradients, gravity, sea-surface height slopes, and by water-mass contrasts
in temperature and salinity that create density-driven (thermohaline) flows; continental shapes,
shelves, ridges, and seasonal monsoons modulate paths, speed, upwelling and reversals
regionally. [1] [2] [3]
Factors that control currents
Wind stress: Trade winds and westerlies impart momentum, pushing surface waters and
setting the subtropical gyres; monsoon winds reverse seasonal currents in the north Indian
Ocean. [2] [1]
Coriolis effect: Deflects moving water right in the Northern Hemisphere, left in the Southern
Hemisphere; organizes basin-scale gyres and westward intensification of narrow, fast
western boundary currents (e.g., Gulf Stream, Kuroshio). [3] [2]
Pressure/sea-level gradients: Equatorial heating makes sea level slightly higher
(~centimetres) than subtropics, driving flow down-slope (often east→west); geostrophic
balance with Coriolis sets persistent currents. [1] [3]
Temperature and salinity: Cooling and/or brine increase density, causing sinking; contrasts
create vertical overturning and deep currents (thermohaline circulation) linked to surface
patterns and upwelling/downwelling zones. [4] [2]
Gravity and friction: Gravity acts on piled-up water; internal and bottom friction shape
current structure and Ekman spirals, affecting coastal upwelling belts. [3] [1]
Basin physiography: Continents, shelves, straits, and ridges steer flows; boundary currents
intensify on the western side of gyres due to latitudinal variation of Coriolis (beta effect). [3]
 Upwelling/downwelling: Wind-driven Ekman transport away from coasts (or at the equator)
brings cold, nutrient-rich water up; convergence zones push water down in subtropical gyre
centres. [5] [3]
Seasonal/atmospheric modes: Monsoons (Indian Ocean), ENSO/El Niño–La Niña (Pacific
equatorial currents), and NAO/SAM alter strength/paths episodically. [6] [2]
World currents by basin (warm vs cold; key drivers)
North Atlantic
Warm: Gulf Stream (western boundary jet transporting subtropical heat poleward; wind
stress, geostrophic flow, westward intensification). [3]
Warm: North Atlantic Current/Drift (extension across to Europe; westerlies/Coriolis). [7]
Warm: Antilles, Florida, Irminger, Norwegian Currents (branches feeding gyre/nordic seas;
wind–Coriolis). [6]
Cold: Canary Current (eastern boundary, slow, equatorward; coastal upwelling under
northeasterly trades/Ekman). [5] [7]
Cold: Labrador Current, East/West Greenland Currents (subpolar gyre branches; cold, often
ice-bearing; density/atmospheric forcing). [7] [6]
South Atlantic
Warm: Brazil Current (western boundary, southward; trades/westerlies gyre forcing). [7]
Cold: Benguela Current (eastern boundary, northward; strong coastal upwelling under SE
trades/Ekman). [5] [7]
Cold: Falkland/Malvinas (northward from ACC, meets Brazil Current near Rio–La Plata;
fronts, eddies). [7]
North Pacific
Warm: Kuroshio (western boundary jet, northward along Japan; westward intensification). [7]
Warm: North Pacific Current/Alaskan Current (eastward drift and subarctic branch;
westerlies). [6] [7]
Cold: California Current (eastern boundary, southward; coastal upwelling under
northerlies/Ekman). [5] [7]
Cold: Oyashio/Kuril (from subarctic/Okhotsk into NW Pacific; nutrient-rich; interacts with
Kuroshio). [6] [7]
South Pacific
Warm: East Australian Current (western boundary, southward; eddy-rich; westerlies/trades).
[6]

Cold: Peru/Humboldt (eastern boundary, northward; intense upwelling under SE

trades/Ekman; crucial for fisheries, ENSO sensitive). [5] [7]
Indian Ocean
 Warm: Agulhas (western boundary, southward along SE Africa; retroflects into eddies
feeding South Atlantic). [6] [7]
Warm: Mozambique Current (Agulhas feeder, relatively stable). [6]
Cold: West Australian Current (eastern boundary, northward; cool leakage from Southern
Ocean; upwelling segments). [7] [6]
Monsoon-driven seasonals (North Indian):
Southwest Monsoon Current (boreal summer, east-to-west and cross-basin flows; winds
reverse currents). [1] [6]
Northeast Monsoon Current (boreal winter, reverse set; Sri Lanka to Bay of Bengal). [6]
Somali Current (reversing boundary current; strong southwest monsoon upwelling in
summer; weaker/changed in winter). [1] [6]
Polar and circumpolar
Antarctic Circumpolar Current (ACC/West Wind Drift): strongest eastward flow encircling
Antarctica, driven by roaring westerlies; links basins, creates fronts; cold. [7]
Antarctic Coastal Current (East Wind Drift): westward near the continent under polar
easterlies. [7]
Equatorial currents (all oceans)
North and South Equatorial Currents: westward under the trades; flanked by an eastward
Equatorial Countercurrent; equatorial upwelling strong in Pacific/Atlantic due to Ekman
divergence (cool SST band). [5] [6]
ENSO modulation: In El Niño, weakened trades reduce upwelling and strengthen eastward
flow of warm anomalies; La Niña enhances the normal pattern (affecting Humboldt/Peru and
equatorial Pacific currents). [6]
How factors map to specific currents
Western boundary jets (Gulf Stream, Kuroshio, Brazil, East Australian, Agulhas): fast, narrow,
warm, poleward—set by wind-driven gyres, westward intensification (beta effect),
geostrophic balance; eddy-rich and high heat transport. [3]
Eastern boundary currents (Canary, Benguela, California, Peru, West Australian): slow,
broad, cold, equatorward; strong coastal upwelling under alongshore winds and Ekman
transport—high nutrients, major fisheries. [5] [7]
Monsoon currents (Somali, SW/NE Monsoon Currents): reverse with seasons; upwelling off
Somalia/Oman during SW monsoon due to offshore Ekman transport. [1] [6]
Polar/subpolar (Labrador, Greenland branches, ACC): driven by high-latitude winds,
buoyancy/density contrasts, sea-ice processes; feed deep-water formation zones or
circumpolar pathways. [3] [7]
Equatorial system (NEC/SEC/Countercurrent): trades + Coriolis divergence drive westward
flows with central countercurrent; equatorial upwelling cools SST and fuels productivity. [5]
[6]

Tips and tricks to remember (no mnemonics; pattern-based cues)

 Picture each ocean gyre: warm, swift poleward on the west side; cool, broad equatorward
on the east side. If standing on the west edge of a basin, expect a warm current going
poleward; on the east edge, expect a cool one going toward the equator. [3] [7]
Upwelling belts live where winds push surface water offshore: eastern margins with
alongshore winds (California, Peru, Canary, Benguela) and at the equator where trade-driven
Ekman transport diverges—think “cool water + great fisheries”. [5]
Indian Ocean is the “seasonal exception”: currents and even the Somali boundary current
flip with the monsoon winds—associate summer with vigorous SW monsoon upwelling off
Somalia/Oman; winter with reversal. [1] [6]
Western boundary currents carry heat toward storm tracks and temperate coasts (Gulf
Stream to NW Europe; Kuroshio to Japan); eastern boundary currents cool dry coasts and
fog them (California, Canary, Peru). [3] [7]
Circumpolar logic: the only uninterrupted path is around Antarctica—hence the strongest
global belt (ACC) flowing east with the westerlies; a weaker westward flow hugs the
Antarctic coast under polar easterlies. [7]
Comprehensive current list (warm vs cold; quick scan)
Warm: Gulf Stream, Florida, Antilles, North Atlantic Drift, Irminger, Norwegian; Kuroshio,
North Pacific/Alaskan; Brazil; Agulhas, Mozambique; East Australian; North/South Equatorial
Currents (surface warm); Equatorial Countercurrent; Tsushima; El Niño anomalies (eastward
warm episodes). [6] [7]
Cold: Canary, California, Peru/Humboldt, Benguela, Labrador, East/West Greenland,
Oyashio/Kuril, Falkland/Malvinas, West Australian, Antarctic Circumpolar (cold belt),
Antarctic Coastal Current; subpolar branches in both basins. [7] [6]
Seasonal/variable (Indian): Somali (seasonally cold/upwelling in SW monsoon), Southwest
Monsoon Current (warm), Northeast Monsoon Current (cooler). [1] [6]
Why this matters (exam-ready linkages)
Climate: Warm western boundary currents moderate nearby land, fuel cyclones; cold
eastern boundaries stabilize, fog, aridify adjacent deserts (e.g., Atacama with Humboldt;
Namib with Benguela). [1] [7]
Fisheries: Upwelling currents (Peru, California, Canary, Benguela) sustain some of the world’s
richest grounds. [5]
Navigation/hazards: Jets and eddies (Gulf Stream/Kuroshio) alter shipping routes and
weather; monsoon reversals redefine Indian Ocean sailing seasons. [1] [3]
Citations
Overview of drivers: wind, Coriolis, pressure/sea-level slopes, gravity, temperature–salinity
density, monsoons; Ekman/upwelling. [2] [3] [1]
Lists and characteristics of major currents across basins; warm vs cold and directions. [6] [7]
Upwelling belts at eastern boundaries and equator; equatorial current structure. [5]
⁂
 1. https://www.pmfias.com/ocean-currents-factors-responsible-formation-ocean-currents-effects-ocean
-currents/
2. https://www.drishtiias.com/to-the-points/paper1/ocean-currents-3
3. https://www.britannica.com/science/ocean-current/Two-types-of-ocean-circulation
4. https://www.nextias.com/blog/movement-of-ocean-water/
5. https://www.coastalwiki.org/wiki/Ocean_circulation
6. https://www.jagranjosh.com/general-knowledge/list-of-ocean-currents-of-the-world-1520339778-1
7. https://vajiramandravi.com/upsc-exam/ocean-currents/
8. https://testbook.com/question-answer/consider-the-following-factors1-rotation-of-th--601c4881127589
dce6b9efeb
9. https://www.drishtiias.com/to-the-points/paper1/ocean-currents-1
10. https://www.nextias.com/blog/movement-of-ocean-currents/