Lecture 10- Ocean Circulation 2 Flashcards

(30 cards)

1
Q

vertical distribution of seawater density

A

directly influences the vertical movement of water in the ocean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What determines seawater density and ocean salinity?

A
  • salt concentration

- water temperature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

surface ocean temperature

A
  • determined by the exchange of heat between the ocean surface and atmosphere
  • measure of the heat energy contained in the ocean
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

when more energy enters than leaves the ocean surface (spring/summer)

A

ocean surface warms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

when more energy leaves than enters the ocean surface (winter)

A

ocean surface cools

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the dominant method of heat loss?

A

evaporative cooling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

depth of light/energy penetration into surface ocean

A

relatively shallow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

depth of light/energy penetration for clearest open waters

A

150 to 200 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

depth of light/energy penetration for turbid coastal waters

A

50 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

typical vertical profile of temperature

A
  • all direct solar heating takes place near the ocean surface (0-30 meters)
  • seawater below 500 meters is uniformly cold
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

permanent thermocline

A

the broad region at 500 meters where the seawater temperature changes from warm to uniformly cold

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

seasonal thermocline

A
  • temporary thermocline

- shallower thermocline only forms in the summer and is erased in the winter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

typically vertical density profile

A

less dense water “floats” above more dense water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

seasonal pycnocline

A
  • region of strong change in density with depth
  • net heat gains in the spring and summer
  • net heat losses in the fall and winter
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

permanent pycnocline

A
  • remains in place at around 500 meters
  • result of the long-term balance between the downward heating/mixing at the surface and upward mixing of cold water from below
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is the ocean more shallow in the summer?

A

heating the water makes it more buoyant so it’s harder for the wind to push it down

17
Q

location of subpolar gyres

18
Q

location of subtropical gyres

19
Q

What describes how the wind drives the surface ocean currents of very large subtropical gyres?

A
  • Ekman transport

- geostrophic currents

20
Q

What causes Ekman transport?

A
  • wind force
  • friction force
  • Coriolis force
21
Q

Ekman transport

A
  • rate of total water transported in Ekman layer

- exactly 90 degrees from the wind direction

22
Q

How thick is the Ekman layer?

A

50 to 100 meters

23
Q

geostrophic balance

A

point at which currents move with steady speed with Coriolis and pressure gradient forces in perfect opposition

24
Q

geostrophic current

A

resulting current from geostrophic balance

25
fully developed currents
move along lines of constant pressure
26
What drives the Ekman layer to the center of the gyre to create a mount of surface water?
westerly and trade winds
27
Coriolis force
always points toward the center of high pressure in the northern hemisphere and requires concentric CW motion
28
western boundary currents
- currents on the western side of subtropical gyres | - swift and narrow jets that bring warm water from the tropics to high latitudes
29
eastern boundary currents
- currents on eastern side of subtropical gyres - broad and slow - bring cold water from the high latitudes to the tropics
30
gyres are indirect results from
winds