Lecture 13/14 - Physical Properties & Biological Oceanography

Question 1

What are isohalines?

Answer 1

These are lines joining points of equal salinity

Question 2

In what ways are surface oceans are more variable than deep waters?

Answer 2

Much greater temperature fluctuation at the surface, as well as salinity and density. All do not change much in the deeper waters

Question 3

What is the Thermocline, Halocline and Pycnocline?

Answer 3

Area in the water column that has a great change in:

1. ) Temperature gradient
2. ) Salinity gradient
3. ) Density gradient

Question 4

What two factors can define water masses, through density?

Answer 4

Water masses characterised by temperature and salinity (relationship is not linear however).

Question 5

What is an example of a large scale current?

Answer 5

The Gulf Stream

Question 6

What is an example of a small scale current?

Answer 6

Gyres and Eddies

Question 7

How do the surface currents move?

Answer 7

Energy from the sun – winds, T S and density

Rotation of the Earth – imparts a velocity to fluids on the surface, degreases towards poles

Question 8

What is the difference between eastern and western boundary currents?

Answer 8

Eastern e.g. Canaries
Broad, Shallow, Slow 10s km / day, Diffuse upwelling

Western e.g. Gulf Stream
Narrow, Deep, Swift 100s km / day, no upwelling

Question 9

What is the Coriolis effect?

Answer 9

Earth rotates, the shallow layer of surface water pushed by wind is deflected right of wind direction in N. Hemisphere and left of wind direction in S. Hemisphere.The deflection is known as the Coriolis effect.

Question 10

What is THC, and what drives it?

Answer 10

Other than being from some wkd gnarly bud, is can also mean the Thermohaline Circulation. This is the part of the ocean circulation which is driven by density differences.
THC is driven by high-latitude cooling. In some regions convective mixing occurs.

Question 11

Methods of THC (4)

Answer 11

Overturning of the world ocean,
Spreading of deep waters
Upwelling of deep waters
Near-surface currents

Question 12

What is an example of phytoplankton?

Answer 12

Diatoms - most abundant form of marine algae. They are one of the major contributors to primary production in coastal waters. drop siliceous ooze when consumed.

Question 13

What are examples of zooplankton and their importance?

Answer 13

Radiolaria form silica walls.

Foraminifera – carbonate shells

Question 14

What is the process of primary production?

Answer 14

Phytoplankton in the ocean use CO2, sunlight, water, and nutrients and produce carbohydrates and oxygen.

Question 15

How does primary production vary across the oceans?

Answer 15

Usually occurs in the open ocean, and coastal regions. The highest area of productivity is upwelling and coastal zones.

Question 16

What is the Redford Ratio?

Answer 16

C : N : P = 106 : 16 : 1

Question 17

Does the chemistry of seawater change from a) surface to depth and b) between oceans?

Answer 17

a. ) Deep water concentration increase in response to the deep water circulation
b. ) Different temperatures, salinities and inputs systems (e.g. river inputs) can change the chemistry between oceans