Thermohaline circulation

Question 1

surface density decrease

Answer 1

precip diminishes salinity

heating by the atm or short wave radiation raise temp

Question 2

surface density increase

Answer 2

evap increases salinity and decreases temp
direct conduction w atm decreases temp
losses by infrared rad decrease temp
freezing of seawater increases salinity just below ice

Question 3

density-induced water movement

Answer 3

see diagram

Question 4

Five most common water masses

Answer 4

surface - 200 m
central and mode - bottom of main thermocline
intermediate - 1500 m
deep - 400 m
bottom - touching floor

Question 5

tracers

Answer 5

conservative - temp and salinity
biogeochemical - O2, silicate, CH4, nitrate, phosphate
chemical - CFCs, C-14, freons

Question 6

bottom water

Answer 6

densest
form through freezing of seawater or evap
in cont shelf or deep basins

Question 7

Antarctic Bottom Water (AABW)

Answer 7

shelf water - very dense water formed on shelf through freezing of seawater (inc in sal)
and cooling under ice shelf (dec temp to below freezing)
water overflows toward cont slope
mixes w circumpolar deep water
= AABW

Question 8

great conveyor belt

Answer 8

the general circuit that water masses accomplish around world ocean
at some high lats, dense waters are formed and sink
then flow at great depths back to low lats
eventually well up to surface
distributes gases, heat, nutrients
upwelling

Question 9

Two routes in Great Conveyor Belt

Answer 9

warm route - equatorial route N of Australia across Indonesia seas and Indian Ocean
Cold route-austral route through Drake passage, south of SA

Question 10

Tech to study currents

Answer 10

mechanical current meters - sensor for speed and sensor for direction
Acoustic Doppler Current Profiler - doppler effect, transmitters and receivers
drifters