Ocean CirculationWinds and Currents

Winds and Currents

• The __________________ and the ___________________ interact

• The ocean and atmosphere transport heat from the ___________________________________________________________

• Winds create daily, ________________ weather changes, while the oceans have a slower, more ________________________ effect on climate

• Currents move much more slowly than winds and retain more heat than the atmosphere

• While winds affect ocean currents, oceans also influence the winds, helping to determine their _________________________________

Current Patterns

Global Wind Patterns

• Winds are caused by __________________ heating and cooling of the atmosphere.

At this animated image you can see the seasonal variations of wind over the World Ocean averaged during several decades of observations

• Warm, humid air rises at the equator and moves towards the poles, where it cools. The cold, dry air sinks (some moves towards the equator forming __________________, and some moves towards the poles forming ________________________) resulting in a circulation pattern of _________________________________.

• The prevailing winds blow _______________ in the Northern Hemisphere and _______________________________ in the Southern Hemisphere.

• The equatorial region is known as the _____________________________: hot moist air rises and cools resulting in thunder clouds. The world’s rain forests are here.

• 30° N and S are known as the ____________________________, where cold, dry air sinks toward Earth’s surface. The world’s great desert regions are found here.

• 60° N and S is where the cold, dry air is flowing south, warming and rising, forming Easterly winds. The poles are actually cold deserts.

Global Current Patterns

• Current:___________________________________________________________________________________________________

• There are two types:– Surface Currents– Deep Currents

• Surface currents: – _________of currents and are mostly wind driven– __________________________ water movement– Follow pattern of prevailing winds– Usually in the top ____________ m of water

• Even though the currents are all connected, we give them different names based on where they are

Surface Current Pattern

• Deep currents: – density driven (depend exclusively on salinity and

temperature)– mainly ____________________ water movement– ___________of all currents– called thermohaline circulation

Deep Currents

Unique Currents

• Equatorial Countercurrent (Cromwell Current): – Lies between the North and South Equatorial

Currents – It is several hundred meters wide– It flows in the _______________________

direction from the currents next to it and we do not have a reason/explanation for this

• Antarctic Current (West Wind Drift):– It’s the world’s largest current – It could fill the Great Lakes in ______ days

• Gulf Stream: – Can reach depths of over __________ m– Can move at a rate of 2 m/s = ~160 km/day which

makes it the ________________ surface current – It is ~__________ km wide– Goes from Florida to NFLD