Lecture 13

Question 1

North Atlantic Deep Water

Answer 1

The sinking of surface water in Greenland that flows southward.

Question 2

What is the key process in the ocean circulation system?

Answer 2

increasing salinity along the gulf stream

Question 3

Mild ice-age

Answer 3

surface water sinks only south of Iceland(no sinking north of iceland). This reduces the amount of water that is circulated.

Question 4

The coldest ice-age mode

Answer 4

Surface water does not sink in the North Atlantic, only a small amount of water is circulated by the conveyor

Question 5

“bipolar see-saw”

Answer 5

cold temperatures in Northern hemisphere accompanied by warm temperatures in the southern hemisphere and vice versa.

Question 6

phytoplankton

Answer 6

plankton that are green plants

Question 7

zooplankton

Answer 7

plankton that do not carry photosynthesis

Question 8

photosynthesis

Answer 8

CO2+H2O+sunlight–>organic material+O2

Question 9

respiration and/or decay

Answer 9

O2–>CO2 + H2O + nutrients

Question 10

What type of relationship does photosynthesis and respiration have?

Answer 10

Closed chemical cycle

Question 11

What are the main nutrients needed for phytoplankton?

Answer 11

• nitrate or ammonium for the Nitrogen
• phosphate for the phosphorous
• dissolved iron

Question 12

Why are Phosphorous and Nitrogen depleted in the photic zone?

Answer 12

being consumed

Question 13

Why are nutrients prevalent below the photic zone?

Answer 13

being produced by decomposition

Question 14

_ of organic matter produced decays in the surface zone and __ decays in the deep ocean.

Answer 14

90%, 10%

Question 15

Why would river deltas be so rich in marine life?

Answer 15

Nutrients from river runoff.

Question 16

“biological pump”

Answer 16

Ocean nutrient cycle where transport of nutrients occurs.

Question 17

Why is the biological pump critical to the Earth system?

Answer 17

nutrients in the deep ocean take around 500 years to return to surface ocean, while in the surface ocean it takes around 1 year. This keeps nutrients in the surface ocean in short supply and ultimately limits ocean productivity.

Question 18

Where is ocean productivity highest?

Answer 18

high latittudes(surface layer very thin or nonexistent)
upwelling regions
near major river deltas