February 1st lecture

Question 1

What is the mixed layer?

Answer 1

homogeneous layer at the ocean’s surfcae within which oceanic properties ( T and S ) change very little.

Question 2

When is the Mixed layer deepest?

Answer 2

During the winter

Question 3

When is the mixed layer the shallowest?

Answer 3

in the summer

Question 4

What does the seasonal change of the mixed layer allow the surface water to do?

Answer 4

It allows for the surface layer of the ocean to be take up by the interior of the ocean (subduction)

Question 5

What factors influence the mixed layer depth? ( 6 things )

Answer 5

• Wind driven mixing
• Stability of underlying water
• Surface buoyancy changes
• Surface heating or cooling
• provision of freshwater to the oceans surface
• Large scale ocean circulation

Question 6

The competition of what two things leads to the Stratification process?

Answer 6

heating/river runoff and cooling/tidal and wind mixnig

Question 7

What does Heating and river run off do to the mixed layer?

Answer 7

Acts to stratify fluid ( layer the surface )

Question 8

What does cooling/Wind and tidal mixing do to the mixed layer?

Answer 8

acts to mix fluid vertically

Question 9

What is the density of sea water dependent on?

Answer 9

Temperature, Salinity and pressure

Question 10

How does pressure affect ocean density?

Answer 10

although water is basically incompressable due to how close their molecules are to one another ,there are still small changes in volume and density that occur due to pressure changes.

Question 11

When is water compressed in the ocean?

Answer 11

In the deep ocean where pressures are 1000x that of the atmospheric pressure, water is compressed by 25

Question 12

How does Temperature influence density?

Answer 12

Density decreases as temperature increases

Question 13

How does Salinity influence density?

Answer 13

Increasing salinity increases density

Question 14

What is density

Answer 14

The interplay of Temperature and salinity to determine the density of water

Question 15

Where are temperature changes most important to the alteration of density?

Answer 15

in the tropics, where the slope of density line is greater for temperature than salinity

Question 16

What has a larger effect on the whole ocean’s density? T or S?

Answer 16

Salinity has a much greater effect, as most of the ocean is cold, thus a temperature change in a local area will not effect the densities of waters around it.

Question 17

Where is salinity change most important in the change in density?

Answer 17

In the higher latitudes, where the slope of density line greater for salinity than for temperature.

Question 18

What is the Equation of state?

Answer 18

a complicated equation that describes how ocean density depends on temperature and salinity as well as pressure

Question 19

In general how do we determine density?

Answer 19

Density is meaused through a calculation from observational measurement of temperature, salinity, and pressure.

Question 20

What is the avarge surface density of the ocean?

Answer 20

1026 kg m-3

Question 21

What is the Pycoline?

Answer 21

A depth range in the ocean where density changes rapidly in the vertical due to changes in Temperature, salinity and pressure

Question 22

Where is the Pycoline usually?

Answer 22

Normally at a depth of 100 - 500m depth

Question 23

What is a thermocline?

Answer 23

It is when there is a rapid change of density associated with temperature

Question 24

What is a Halocline?

Answer 24

A rapid change in density associated with salinity