Ocean Circulation

Question 1

what dictates ocean circulation?

Answer 1

wind and currents

Question 2

what do ocean contain?

Answer 2

large currents. gyres and eddies

Question 3

what are currents?

Answer 3

continuous streams of water than are both permanent channels and also periodic

Question 4

what are boundary currents?

Answer 4

very large ocean currents that run along continent
- Gulf stream

Question 5

what are gyres?

Answer 5

massive circular or spiraling circulation patterns that are thousands of km in diameter that are bordered by permanent boundary currents
-> Beaufort gyre

Question 6

what affects gyres?

Answer 6

Coriolis effect and wind

Question 7

what are eddies?

Answer 7

smaller circular pockets of water that break off from Boundary current
- temporary
- cold or warm depending on boundary current
- important for dispersal of animals and plankton

Question 8

how does the Gulf Stream affect NY?

Answer 8

• brings warmer water to coast
• nutrient influx
• alters ecosystem

Question 9

what is an example of what occurs in gyres?

Answer 9

loggerhead sea turtles stay within North Atlantic subtropical gyre

Question 10

what warms the oceans?

Answer 10

sun
- warms the surface of ocean
- ocean warm atmosphere
- some of the radiation is absorbed and some of it is reflected (greenhouse effect)

Question 11

where is there a surplus of radiation?

Answer 11

40N and 40S (equator)

Question 12

what drives the general circulation of the atmosphere?

Answer 12

the sun

Question 13

where is the surplus of heat energy transferred by?

Answer 13

atmosphere and oceans to higher latitudes

Question 14

what happens when hot air rises at the equator?

Answer 14

increased precipitation
- air is less dense
- lose of moisture = lots of precipitation

Question 15

what kind of cell is at the equator?

Answer 15

hadley

Question 16

what happens with rising air?

Answer 16

takes pressure off the earth

Question 17

what happens when air is cool?

Answer 17

more dense and falls

Question 18

what kind of cells are the closest to the poles?

Answer 18

polar

Question 19

what kind of cell is in between hadley and polar?

Answer 19

ferrel

Question 20

what is the polar front?

Answer 20

extra cold area between ferrel and polar

Question 21

what is horse latitudes?

Answer 21

• air goes down and dissipates
• not windy
• boats were moving so slowly that they threw the horses overboard

Question 22

what are doldrums?

Answer 22

no wind bc the air is heated and only moves up

Question 23

why is the wind curved?

Answer 23

bc of the Coriolis effect

Question 24

in what direction do objects deflect in the northern hemisphere?

Answer 24

right
- increasing deflection of moving water parcel to the right

Question 25

in what direction do objects deflect in the southern hemisphere?

Answer 25

left - increasing deflection to the left

Question 26

is there deflection at the equator?

Answer 26

no

Question 27

why is there deflection?

Answer 27

- the earth is moving faster than the water so there is deflection -> earth's rotation (objects at equator move faster than objects at poles - gravity (centrifugal forces) - objects are pulled towards earth by gravity and objects are spun fast around earth by centrifugal forces

Question 28

how is energy transferred from winds to the upper layer of the ocean?

Answer 28

through friction between the ocean and atmosphere at the sea-surface

Question 29

what causes ocean currents?

Answer 29

friction of atmospheric currents on ocean

Question 30

where does atmospheric circulation occur?

Answer 30

at the surface of earth

Question 31

what makes circulation patterns more chaotic?

Answer 31

continents - westerlies and trade winds are still evident

Question 32

what drives ocean currents?

Answer 32

winds

Question 33

what shapes water?

Answer 33

land - water contained by land creating circular patterns - more inertia in water than air

Question 34

how many subtropical gyres are there?

Answer 34

5

Question 35

what kind of currents are in subtropical gyres?

Answer 35

strong western boundary currents - warm water away from the equator -> Gulf stream, Brazil currents, Kuroshio current, East Australian currents, Agulhas current

Question 36

what kind of water are in strong eastern boundary currents?

Answer 36

cold water - from poles to the equator

Question 37

what is Ekman Transport?

Answer 37

- deflection of water 90 degrees - bc of friction (of wind on water and water layers on water layers) - leads to upwellings

Question 38

what causes each successive sheet of water to deflect relative to sheet above?

Answer 38

Coriolis effect

Question 39

what generates an Ekman transport?

Answer 39

wind along a coast

Question 40

what is a result of an upwelling?

Answer 40

nutrient-rich water deeper waters move to the surface to replace water transported offshore

Question 41

what are in deep waters and the result?

Answer 41

more nutrients and with sunlight the new nutrients fuels phytoplankton blooms which can support huge fish abundances making them productive

Question 42

El Nino

Answer 42

southern oscillation - equatorial current "slackens" - unknown - warm water stays and slooshes back - stratification of water means layers = very shallow or no thermocline - no upwelling, no nutrients brought to surface = poor fisheries

Question 43

La Nina

Answer 43

- equatorial current = warm water - strong upwelling off Peru - steep thermocline - cold deep water brought to the surface - deep water brings nutrients to surface - generates phytoplankton blooms, increasing zooplankton, which means lots of food for fish = good fisheries

Question 44

what occurs during La Nina?

Answer 44

- trade winds blow across Pacific (E to W) - generate steep thermocline and strong upwelling off Peru

Question 45

what occurs during El Nino?

Answer 45

- warm winds blowing down along South America coast - warm water current flow E - thermocline drops = stratification

Question 46

thermohaline circulation

Answer 46

- high latitude surface waters have low salinity and low temp -> high density - dense water sinks - moves to lower latitudes at depth - generates a massive ocean river from Arctic to Antarctic and back

Question 47

what is thermohaline circulation called?

Answer 47

global conveyor belt

Question 48

how does cold water reheat in the south?

Answer 48

the upwelling brings the cold water upwards to reheat