Oceans

Question 1

define salinity

Answer 1

amount of salts in seawater (g/kg)

Question 2

define thermocline zone

Answer 2

surface to 100m depth of ocean; temp drops off very quickly past this point

Question 3

define halocline zone

Answer 3

salinity increases rapidly around 100m depth; fresh waters are less dense than salty waters so they remain near the surface

Question 4

describe stratification

Answer 4

• temp & salinity changes with depth

- large stratification = no mixing

Question 5

advantages of remote sensing of the ocean

Answer 5

global and simultaneous coverage over large scales

Question 6

limitations of remote sensing of the ocean

Answer 6

• can only observe surface
• missions are recent and last only years
• instruments suffer from calibration/drift issues
• missions cost $$$

Question 7

describe upwelling

Answer 7

• upward movement of water toward the surface

- new water is almost always cold relative to the water it replaces (stratification)

Question 8

describe the coriolis force

Answer 8

• due to earth’s rotation, all objects moving in the northern hemisphere are deflected to the right (to the left in southern)

Question 9

describe the Ekman drift

Answer 9

• mechanical response of the ocean to wind blowing across its surface
• surface water is dragged along with the wind
• due to coriolis, deflected somewhat to the right in the northern hemisphere
• net transport of water is slightly to the right (north)

Question 10

what’s responsible for upwelling

Answer 10

ekman drift

Question 11

define chlorophyll

Answer 11

• what makes plants green

- chemical responsible for photosynthesis

Question 12

describe the chlorophyll distribution

Answer 12

• high in places where upwelling occurs

- low in places where the sinking motion of Ekman/coriolis dominate

Question 13

describe gyres

Answer 13

• frictional effects of winds on the ocean, generate circulation
• organized in gyres that rotate CW in northern hemi, CCW in southern

Question 14

where is salinity the highest

Answer 14

atlantic basin (lots of evaporating pools)

Question 15

describe thermohaline circulation

Answer 15

• in northern hemi, atmosphere extracts huge amounts of heat from the north atlantic
• water gets denser –> sinks to the bottom of the ocean
• eventually spreads throughout the global ocean & returns to the surface
• whole process takes about 1000 years

Question 16

how does the ocean affect the annual range of surface air temperature

Answer 16

closer you are to the ocean –> less range