chapter 2 part 3

Question 1

environmental importance of upwelling

biological role:

Answer 1

• distruction of submerged organic matter (defunct plankton)
• bottom water is rich in biogenic elements such as nitrogen and phosphorous
• bottom water float to the surface
• phytoplankton actively consume the biogenes

Question 2

High values of primary productivity is observable at

Answer 2

Higher levels of the food chain

• phytoplankton
• zooplankton
• filter feeding organisms
• fishes
• marine mammals and birds

Question 3

Example of high productivity:

Answer 3

in the vicinity of the Peruvian upwelling, the fish capacity is 100 times higher than that in the adjoining areas of the ocean. Here, about 20% of the world fishery catch is produced.

Question 4

Accumulations of organic matter at the bottom, covered with layers of deposits can change into:

Answer 4

Oil (upwelling influence oil extracting industry)

Question 5

Climate change with increasing altitude

Answer 5

• Temperature increase (stable temperature inversion)
• The inversion prevent the penetration of moist marine air at higher altitude and inland
• The inversion limit vertical cloud formation and moisture concentration is deposited within a thin surface layer in the formation of fog ex: near-shore zone of Sakhalin Island (North of Japan)

Question 6

Intensive upwelling and the climate:

Answer 6

• Precipitation lacking in the area
• Narrow coastal belts are distinguished by their arid climate. Ex: pacific coasts of peru and chile

Question 7

Alternation of upwelling and downwelling and the climate

Answer 7

• Water surface temperatures are lower than other areas

Question 8

Impacts of downwelling

Answer 8

• Allow deep ocean ventilation to occur because:
  
  • Water bring dissolved oxygen down to facilitate aerobic respiration in organisms
  • Without this the dissolved oxygen would be quickly consumed by biological processes. Ex: anaerobic bacteria would take over decomposition, leading to a build-up of hydrogen sulfide
• Without renewal mass extinction might occur

Question 9

Thermocline:

Answer 9

• The transition layer between mixed layer at the surface and the deep water layer (definition of layers based on temperature)
• Temperature decrease rapidly from the mixed layer temperature to the much colder deep water temperature

Question 10

Mixed layer:

Answer 10

• (near the surface) temperature is roughly that of surface water

Question 11

Mixed layer and deep water layer

Answer 11

• Relatively uniform in temperature
• Thermocline represent the transition zone between the two

Question 12

Thermocline characteristics:

Answer 12

• Thin layer in large body of fluid
• Temperature change more rapidly with depth than other layers above or bellow

Question 13

Thermocline in the ocean

Answer 13

• Though of as blanket that spate upper mixed layer from the calm deep water bellow

Question 14

Semipermanent thermoclines:

Answer 14

• Depend on:
  
  • Season
  • Latitude
  • Turbulent mixing by wind

Question 15

Temporary thermoclines:

Answer 15

• In response to radiative heating/cooling of surface water during the day/night

Question 16

Factors that effect the depth and thickness of thermocline:

Answer 16

• Seasonal weather variation
• Latitude
• Local environmental conditions
  
  • Such as tides
  • Currents

Question 17

Temperature change with depth: –>

Answer 17

• Temperature decreases from the surface to the deepest levels except in high latitudes (polar and sub polar) where configuration is complex

Question 18

(thermocline depth):

Answer 18

• Range from (50 to 1000m)
• Depend on geographical location
• Vary seasonally (specially in mid-latitude) where secondary and much shallower thermocline occur in summer
• Appear seasonally in high latitudes
• Vary from one year to the next as in tropical pacific where thermocline vertical displacement plays a fundamental role during ENSO

Question 19

Enso:

Answer 19

El Niño–Southern Oscillation (ENSO) is an irregularly periodical variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting much of the tropics and subtropics. The warming phase is known as El Niño and the cooling phase as La Niña.

Question 20

Deeper thermohaline is observed during:

Answer 20

• El Nino years which limit the amount of nutrients brought to shallow depths by upwelling which greatly impact the years fish crop

Question 21

Trade wind and El nino

Answer 21

• During an El Niño event, the southeast trade winds weaken and so does the amount upwelling in the eastern Pacific.

Question 22

The deeper thermocline means that:

Answer 22

• any upwelling that does occur is unable to tap into the rich nutrients found in deeper waters
• warm nutrient-poor water predominate the region and a decrease in the fish population is observed