ocean structure and circulation

Question 1

how severe is ocean mixing?

Answer 1

Relatively stable vertical layers (limited mixing)

Question 2

what two gradients exist

Answer 2

temp and salinity

Question 3

describe temp gradient

Answer 3

Temperature: warmest at the surface b/c sun heats from the top; thermocline is the layer
between surface water and deep water; rapid decline until stable temp
- Colder water = more dense

Question 4

describe salinity gradient

Answer 4

Salinity: low salinity at surface b/c diluted by precipitation; followed by steep gradient
until it equalizes; halocline is the salinity gradient b/w less saline surface water and more
saline intermediate water
- More saline = more dense

Question 5

what is pycnocline? when is it reduced?

Answer 5

Thermocline + Halocline = Pycnocline: separation between surface zone and deep zone
Higher latitude = reduced pycnocline

Question 6

describe upwelling

Answer 6

Mix slowly with surface water
-Upwelling: surface water organisms die and sink to sea floor increasing the nutrient
concentration. Upwelling occurs (at margins of continental plates ie. where land meets
water) causing the water to rise and nutrients to come to the surface acting as fertilizer for
primary producers

Question 7

how do the deep ocean layers function in terms of productivity

Answer 7

long term sinks for carbon and source of nutrients -> productivity