Effects of ocean currents
Topic: Movements of Ocean Water: Waves, Tides and Currents · NCERT: Class 11, Ch 13 "Movements of Ocean Water"
Meaning
Ocean currents carry heat across the oceans. This changes the climate of the coasts next to them.
- Cold currents off tropical and subtropical west coasts make these coasts cool, foggy and dry. This is why coastal deserts form there.
- Warm currents off west coasts in middle and high latitudes give a mild marine climate, with cool summers and mild winters.
- Warm currents off tropical east coasts give a warm, rainy climate.
Currents also move heat towards the poles. They also create rich fishing grounds where cold, nutrient-rich water rises from below or where warm and cold currents meet. They carry icebergs, oil spills and plastic.
Example
The warm North Atlantic Drift keeps Britain and Norway mild. It also keeps Norwegian ports such as Hammerfest and Narvik free of ice in winter, even though they lie far to the north.
Don't confuse with
- "All west coasts have cold currents": this is false. West coasts at high northern latitudes, such as north-west Europe, have warm currents.