Hydrosphere 1 session 2

Question 1

What are the 2 main drivers of ocean currents?

Answer 1

wind or gravity

Question 2

What are the 2 main types of ocean currents?

Answer 2

surface
thermohaline

Question 3

What are surface currents driven by?

Answer 3

winds

Question 4

What ocean volume is affected by wind/ surface currents?

Answer 4

10% by volume only upper ocean

Question 5

What is ocean stratification?

Answer 5

the layering of the ocean due to density (usually temp but can be salinity)

Question 6

What is the surface zone of the ocean?

Answer 6

2% volume well mixed by waves and currents

Question 7

What is the pycnocline?

Answer 7

18% volume layer of rapidly changing density

Question 8

What is the deep ocean zone?

Answer 8

stable 80% volume

Question 9

Why is water good at storing heat?

Answer 9

due to high het capacity

Question 10

Why are ocean climate relatively mild?

Answer 10

ocean absorbs heat in summer and releases heat in winter

Question 11

What are the 3 ways of heat transfer?

Answer 11

conduction
convection
radiation

Question 12

What is conduction?

Answer 12

molecular agitation without motion of the material as a whole (heat diffusion)

Question 13

What is convection?

Answer 13

by mass motion in a fluid (gas or liquid)

Question 14

What is radiation?

Answer 14

by particles (photons) or waves through empty space

Question 15

What is the Coriolis effect?

Answer 15

controlled by how earth spins on axis
NH to the right
SH to the left

Question 16

What is a geostrophic gyre?

Answer 16

oceanwide circular current bounded by the continents, westerly winds, and the trade winds

Question 17

What is gyre circulation like?

Answer 17

clock-wise in the northern hemisphere and counter clock-wise in southern hemisphere

Question 18

What causes gyres?

Answer 18

wind friction
Coriolis effect

Question 19

How do wind friction and the Coriolis effect currents below the surface?

Answer 19

NH Coriolis deflects wind to right
Next layer down does not feel the wind,
but the movement of the water above exerts a force

Question 20

What is the average movement for the whole water column in the NH?

Answer 20

90* to right of wind direction

Question 21

What is the net motion of fluid (90* to wind) called?

Answer 21

Ekman transport

Question 22

What creates gyres?

Answer 22

water piles up NH due to right movement of water
Pressure gradient created
Gravity pulls some water back down slope

Question 23

What are geostrophic gyres a balance between?

Answer 23

as direction 45* balance between Coriolis effect and pressure gradient

Question 24

What causes upwelling in NH?

Answer 24

wind comes from north
water moved offshore by Ekman transport
Water has to rise to fill water moved out (downwelling opposite wind south water pushed out as surface water goes closer to coast?