Ocean Physics

Question 1

What is motion in the surface oceans primarily driven by?

Answer 1

Wind - through friction between the atmosphere and ocean

Question 2

At what latitudes do the subtropical gyres lie? and what lies between them in the North/South atlantic?

Answer 2

30 degrees N&S. 0-30 degrees North is a region of downwelling, whilst 0-30 degrees south is a region of upwelling.

Question 3

Evaporation increases surface salinity, but where is this highest?

Answer 3

The subtropics of the Atlantic - more evaporation and little precipitation compared to equator.

Question 4

Under what circumstance does downwelling occur?

Answer 4

Where two deflected water masses meet.

Question 5

Saline, cold waters are most dense, but in the Mediterranean intermediate water, which of these is most influential?

Answer 5

Salinity

Question 6

Deep water formations off the N and S American coasts transport what to the Indian and Pacific oceans? And what is received in return?

Answer 6

Transport cold, salty deep water currents to Indian and Pacific oceans, in return for warm, shallow currents.

Question 7

What is the difference in cause of motion for surface and deep waters?

Answer 7

Surface - primarily wind driven.

Deep - density changes and mixing

Question 8

What three things is air-sea gas exchange a function of?

Answer 8

Temperature, pressure difference between surface ocean and atmosphere and wind (turbulence)

Question 9

Where is dissolved oxygen concentration in the oceans highest? Why?

Answer 9

In the polar regions (particularly the Arctic), decreasing to equator. Because warmth of subtropics cannot retain as much.

Question 10

Where is most CO2 taken into the ocean? Where is the most degassed and why?

Answer 10

CO2 taken in 30-60 degrees latitude N&S (but higher in N Atlantic as colder and more downwelling). It is mostly degassed between the tropics, in the Pacific ocean as warmer and more upwelling.

Question 11

CO2 + H20 H+ + HCO3- 2H+ + CO32- in the oceans. What are the concentrations of the different carbon types under normal marine conditions?

Answer 11

[CO2(aq)]/[HCO3-]/[CO32-] is approx. 0.5% / 86.5% / 13%.

Question 12

Of the 340GtC released by man, what contributed 240? What contributed around 100?

Answer 12

240 - fossil fuel use and cement production

100 - land use change

Question 13

How many GtC/year currently dissolve in the ocean? What % fossil fuel emissions does this represent between 1800-1994?

Answer 13

2.2 GtC/yr

48%