chapter2 part2

Question 1

Compare upwelling and down welling

Answer 1

• Down welling is the opposite of upwelling
• Areas of down welling are smaller than areas of up welling

Question 2

Areas of down welling:

Answer 2

• the coastal waters of Antarctica (basically, the Weddell Sea) and
• the North Atlantic (predominately off the Greenland coast)

Question 3

Mechanisms of down welling

Answer 3

differ from each other in different regions

Question 4

Cause of formation of high density water

Answer 4

(vicinity of Greenland/its rate of down welling is 5 million m3/s)

• passage of cold dry continental air over the ocean
• high salinity of water transferred by the gulf steam and its extensions (Irminger, Norway, and West Spitsbergen currents)

Question 5

Cause of increase in specific gravity and fast down welling

Answer 5

• quick evaporation
• cooling of already dense (by virtue of high salinity) water

Question 6

Cause of high density in Antarctic down welling:

Answer 6

• formation in winter in SH

the release of salts dissolved in the seawater when it is frozen and turns into ice –> The water below the ice proves to be “overloaded” with salts to the extent that it begins to gravitate to the bottom

Question 7

In the Weddell Sea, about

Answer 7

25 million m3 of water with salinity of 34.68% and temperatures less than 0C—that is, approximately 5 times more than in the Arctic down welling—sinks to the bottom.

Question 8

Third mechanism of forming dense water:

Answer 8

• displacement of cold and warm water masses
  
  • down willing intensity is low because the water in those zones has an intermediate density

Question 9

Third mechanism of forming dense water Exist in:

Answer 9

• zones of interaction between:
  
  • kuroshii and Oyashio currents in the Pacific Ocean
  • Labrador current and the gulf stream in North Atlantic

Question 10

The fourth mechanism of forming dense water

Answer 10

• Occur under conditions of water-induced surges

Question 11

Impact of upwelling and down willing on human activity:

Answer 11

• Fisheries
• Recreational activities

Question 12

They play a major

Answer 12

• ecological role
• climate forcing role

Question 13

Importance of upwelling for fisheries

Answer 13

• although upwelling areas are small they provide a lot of fish that we harvest
• recreational activities: abrupt drop in water temperature on costal zones

Question 14

Most productive upwelling zones:

Answer 14

• off the shores of
  
  • Peru,
  • Bengal (India), and
  • the Canary Islands.

Question 15

Give an example of short lived wind induced upwelling:

Answer 15

• arise in the black sea and decrease water temperature by 3 to 5 degrees C
• in 2004, periodical upwelling (5-6days)
  
  • caused:
    water temperature to drop at the black sea health resorts to 13-14 degrees C
  • resulted in:
    ruining the swimming season

Question 16

The biological role of upwelling is great. The bottom waters are rich in such

Answer 16

biogenic elements as nitrogen and phosphorus

Question 17

The biological role of upwelling is great. The bottom waters are rich in such biogenic elements as nitrogen and phosphorus. Their availability there is caused by

Answer 17

destruction of submerged organic matter (generally, defunct plankton)

Question 18

The biological role of upwelling is great. The bottom waters are rich in such biogenic elements as nitrogen and phosphorus. Their availability there is caused by destruction of submerged organic matter (generally, defunct plankton). When the bottom waters float to the surface

Answer 18

phytoplankton begin to actively consume the biogenes.

Question 19

When the bottom waters float to the surface, phytoplankton begin to actively consume the biogenes. The high values of primary productivity continue to be observable at the higher levels of the food chain

Answer 19

(phytoplankton → zooplankton → filter-feeding organisms → fishes → marine mammals and birds).

Question 20

The high values of primary productivity continue to be observable at the higher levels of the food chain (phytoplankton → zooplankton → filter-feeding organisms → fishes → marine mammals and birds). For example,

Answer 20

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 21

Depending on particular conditions, the manifestations of upwelling can be

Answer 21

diverse

Question 22

Depending on particular conditions, the manifestations of upwelling can be diverse, but, in any case, the effect of upwelling on biological productivity is excellent. Eventually,

Answer 22

agglomerations of organic matter at the bottom, covered with layers of deposits, can change into oil. Therefore, one can talk, to some extent, of the influence of upwelling on the oil extracting industry.

Question 23

Upwelling is of essential importance to

Answer 23

climate

Question 24

Upwelling is of essential importance to climate. When temperatures at the water surface are low, the air layer

Answer 24

contiguous to it is also cooled

Question 25

Upwelling is of essential importance to climate. When temperatures at the water surface are low, the air layer contiguous to it is also cooled. Therefore, with increases in altitude, ……………………………..

Answer 25

air temperatures increase rather than decrease

Question 26

Upwelling is of essential importance to climate. When temperatures at the water surface are low, the air layer contiguous to it is also cooled. Therefore, with increases in altitude, air temperatures increase rather than decrease, as is usual; that is,

Answer 26

stable temperature inversions are characteristic of upwelling zones

Question 27

Therefore, with increases in altitude, air temperatures increase rather than decrease, as is usual; that is, stable temperature inversions are characteristic of upwelling zones. These inversions

Answer 27

prevent the penetration of moist marine air at higher altitudes and inland.

Question 28

Therefore, with increases in altitude, air temperatures increase rather than decrease, as is usual; that is, stable temperature inversions are characteristic of upwelling zones. These inversions prevent the penetration of moist marine air at higher altitudes and inland. The inversions also limit

Answer 28

vertical cloud formation; therefore, all deposits of moisture concentrate within a thin surface layer, resulting in the frequent formation of fogs.

Question 29

The inversions also limit vertical cloud formation; therefore, all deposits of moisture concentrate within a thin surface layer, resulting in the frequent formation of fogs. Fogs are particularly noted in the

Answer 29

near-shore zone of Sakhalin Island (North of Japan).

Question 30

In areas of intensive upwelling, precipitation is

Answer 30

lacking during much of the year.

Question 31

In areas of intensive upwelling, precipitation is lacking during much of the year. Consequently, the narrow coastal belts in such areas are

Answer 31

distinguished by their arid climate

Question 32

In areas of intensive upwelling, precipitation is lacking during much of the year. Consequently, the narrow coastal belts in such areas are distinguished by their arid climate. A striking example of this is provided by the

Answer 32

Pacific coasts of Peru and Chile

Where there is an alternation of upwelling and downwelling, water surface temperatures are, on average, lower than those in other areas. The climatic effects of such zones are similar, although they are not particularly noticeable.

Question 33

Downwelling allows for

Answer 33

deep ocean ventilation to occur because these waters are able to bring dissolved oxygen down from the surface to help facilitate aerobic respiration in organisms throughout the water column.

Question 34

Downwelling allows for deep ocean ventilation to occur because these waters are able to bring dissolved oxygen down from the surface to help facilitate aerobic respiration in organisms throughout the water column. Without this renewal, the

Answer 34

dissolved oxygen in the sediment and within the water column would be quickly used up by biological processes.

Question 35

Without this renewal, the dissolved oxygen in the sediment and within the water column would be quickly used up by biological processes. In the instance of decay,

Answer 35

anaerobic bacteria would take over decomposition, leading to a build-up of hydrogen sulfide.

Question 36

. Without this renewal, the dissolved oxygen in the sediment and within the water column would be quickly used up by biological processes. In the instance of decay, anaerobic bacteria would take over decomposition, leading to a build-up of hydrogen sulfide. In these toxic conditions, there are

Answer 36

very few benthic animals that would survive

Question 37

In these toxic conditions, there are very few benthic animals that would survive. In the most extreme cases, a lack of downwelling could possibly lead to

Answer 37

mass extinction

Question 38

Paleontologists have suggested that 250 million years ago,

Answer 38

deep ocean ventilation slowed nearly to a halt, and the ocean became stagnant.

Question 39

……………………………………… filled the deep ocean and progressed onto the continental shelves

Answer 39

. Low oxygen, sulfide and methane-rich waters

Question 40

Low oxygen, sulfide and methane-rich waters filled the deep ocean and progressed onto

Answer 40

the continental shelves, wiping out 95% of all marine species in the greatest extinction event in Earth history, the Permian extinction

Question 41

The thermocline

Answer 41

the transition layer between the mixed layer at the surface and the deep water layer. The definitions of these layers are based on temperature.

Question 42

The mixed layer is near

Answer 42

the surface where the temperature is roughly that of surface water

Question 43

In the thermocline, the temperature

Answer 43

decreases rapidly from the mixed layer temperature to the much colder deep water temperature.

Question 44

The mixed layer and the deep water layer are

Answer 44

relatively uniform in temperature, while the thermocline represents the transition zone between the two.

Question 45

Thermocline

Answer 45

a thin but distinct layer in a large body of fluid (e.g. water, such as an ocean or lake, or air, such as an atmosphere), in which temperature changes more rapidly with depth than it does in the layers above or below

Question 46

In the ocean, the thermocline may be thought of as

Answer 46

an invisible blanket which separates the upper mixed layer from the calm deep water below.

Question 47

………………………………………… , thermoclines may be a semi-permanent feature of the body of water in which they occur, or they may form ………………………………

Answer 47

Depending largely on season, latitude and turbulent mixing by wind

temporarily in response to phenomena such as the radiative heating/cooling of surface water during the day/night

Question 48

Factors that affect the depth and thickness of a thermocline include

Answer 48

seasonal weather variations, latitude, and local environmental conditions, such as tides and currents.

Question 49

In general the sea water temperature decreases from

Answer 49

the surface to the deepest levels, except in high latitudes (polar and sub-polar oceans)where the configuration can be more complex.

Question 50

Depending on the ……………………., the thermocline depth ranges from about

Answer 50

geographical location

50m to 1000m

Question 51

In the tropics, the thermocline can be

Answer 51

quite shallow on average, as in the Eastern Pacific (50m), or deeper as in the western part (160-200m).

Question 52

In extra-tropical regions a permanent (or main) thermocline is found between

Answer 52

200m and 1000m

Question 53

However the thermocline depth varies

Answer 53

seasonally

Question 54

However the thermocline depth varies seasonally, especially in

Answer 54

the mid-latitude regions where a secondary and much shallower thermocline (above 50m) occurs in summer

Question 55

In high latitudes, a thermocline may appear only

Answer 55

seasonally

Question 56

thermocline may appear only seasonally. Thermocline can also vary from

Answer 56

one year to the next, as in the tropical Pacific where thermocline vertical displacements play a fundamental role during ENSO.

Question 57

In many situations, the thermocline can be identified when

Answer 57

the vertical contrasts of salinity are small.

Question 58

A deeper thermocline (often observed during

Answer 58

El Niño years)

Question 59

A deeper thermocline (often observed during El Niño years) limits

Answer 59

the amount of nutrients brought to shallower depths by upwelling processes, greatly impacting the year’s fish crop.

Question 60

During an El Niño event, the

Answer 60

southeast trade winds weaken and so does the amount upwelling in the eastern Pacific.

Question 61

The deeper thermocline means that

Answer 61

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