Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ocean Biogeochemistry > Week 1 > Flashcards

Week 1 Flashcards

1
Q

ocean biogeochemistry

A

interactions of processes that control the cycling of key element, like carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the 3 components of oceanography?

A

-physical
-chemical
-biological

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

why does the ocean matter when it comes to global warming?

A

air-sea exchange of carbon dioxide impacts atmospheric carbon dioxide, modifying the greenhouse effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

key elements in the ocean

A

carbon, nitrogen, phosphorus, iron, silicon, and oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

DIC

A

dissolved inorganic carbon
CO2 dissolved in the ocean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

photosynthesis converts DIC to

A

POC (particulate organic carbon)
DOC (dissolved organic carbon)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

biological pump

A

Transport of carbon from the
surface to the deep ocean by biological processes
(mainly through sinking organic matter).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

solubility pump

A

Combined influence of physical and chemical processes on ocean concentrations of dissolved CO2 and air-sea exchange (independent of biology).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

aerosol effect

A

when we burn fossil fuels, it releases particles into the atmosphere which helps reflect solar energy away. also affects cloud formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pre-industrial atmospheric CO2 concentrations were

A

quite stable for thousands of years, ~280 ppm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Anthropogenic activities have increased atmospheric
CO2 concentrations by

A

> 120 ppm since the mid-1800’s, recently exceeding 400ppm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Atmospheric CO2 concentrations were ~80 ppm lower
during glacial (ice age) periods, much of this
carbon was likely stored

A

in deep ocean

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

photosynthesis

A

plants combine carbon dioxide, water, and
light energy to form plant biomass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

respiration

A

Oxygen is used to break down biomass to
produce carbon dioxide, water and energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

remineralization

A

The breakdown of organic matter into
elemental and nutrient constituents (aka decomposition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Gross Primary Production (GPP)

A

total carbon “fixation“ (photosynthesis), conversion from CO2 to C-biomass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Net Primary Production (NPP)

A

total carbon fixation by plants - their respiration costs. Organic matter supplied by NPP is available to support heterotrophic organisms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

phytoplankton account for how much total photosynthesis in the ocean?

A

95%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Euphotic Zone

A

thin layer at ocean surface (~100m) with enough light to support photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

the most common growth-limiting nutrients for
phytoplankton in the oceans are

A

nitrogen, phosphorus, iron, and silicon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

nitrogen

A

nitrate, NO3- and ammonium NH4+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

phosphorus

A

phosphate, HPO42-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

silicon

A

silicate, H3SiO4- (aka H4SiO4 silicic acid)

24
Q

iron

A

most dissolved iron ions are bound to organic molecules called ligands (>99%), very small amount as free Fe ions

25
Q

How does the biological pump effect the concentration of organic matter in the ocean? How are the exported nutrients returned?

A

It depletes surface concentrations and increases deep ocean concentrations.
Ocean mixing and circulation eventually returns these exported nutrients to surface waters.

26
Q

How does the biological pump move the organic matter?

A

Mainly through sinking POM (>90% of export) and through mixing and advection, which can carry POM and DOM produced in surface waters into the ocean interior.

27
Q

POM

A

particulate organic matter

28
Q

DOM

A

dissolved organic matter

29
Q

Wind Mixing

A

direct mixing by winds. pretty shallow, can extend to ~100m

30
Q

Convective mixing

A

occurs at higher latitudes, can mix much deeper than wind mixing (»500m)

31
Q

Surface mixed layer

A

surface layer where rapid mixing results relatively uniform concentrations of passive tracers (i.e. DIC, nutrients, phytoplankton, etc)
can range from a few meters to hundreds of meters depth, with convective mixing

32
Q

pycnocline

A

sharp change in density with depth

33
Q

thermocline

A

change in temperature with depth

34
Q

halocline

A

change in salinity with depth

35
Q

typically there is a ____ at the base of the surface mixed layer, may appear only seasonally.

A

pycnocline

36
Q

density is a function of

A

temperature and salinity

37
Q

Density ____ as temperature _____

A

increases
decreases

38
Q

Density ____ as salinity _____

A

increases
increases

39
Q

Stable (or stratified) water column

A

lighter waters over denser waters
weak vertical exchange

40
Q

Unstable water column

A

denser waters over lighter waters
convective mixing will result with strong vertical exchange

41
Q

At _____ the temperature profile ______, with increased stratification during summer months, weakened during winter.

A

mid-latitudes
varies seasonally

42
Q

_____ are strongly stratified by _______.

A

low latitudes
temperature

43
Q

____ at mid- to high latitudes is a key route for deep ocean _______.

A

convective mixing
nutrients to return to the surface

44
Q

The second major return route is through ______________, which brings deeper waters to the surface.

A

wind-driven upwelling

45
Q

Vertical mixing largely determines the ______ to surface waters. The depth of the surface mixed layer also controls the _______ experienced by the phytoplankton.

A

flux of nutrients
light levels

46
Q

Increased mixing can _______ to surface waters, but may also lead to _______ of phytoplankton growth rates, if they spend too much time at depth.

A

introduce nutrients
light-limitation

47
Q

seawater is how much percent pure water (H2O)?

A

96.5%

48
Q

3.5% of seawater is dissolved matter. how many ppm is this?

A

35 parts per thousand

49
Q

Iron and aluminum are highly ______, resulting in short residence times due to ____________.

A

particle reactive
particle scavenging

50
Q

Iron and aluminum are removed from the ocean waters to the sediments by _______ then particle sinking (bio pump), AND _____ onto particles

A

biological uptake
by adsorption (scavenging)

51
Q

____ species have a strong tendency to stick (or adsorb) to sinking particles, eventually transferred to sediments.

A

particle reactive

52
Q

____ is one of the key nutrients that limits phytoplankton growth and thus NPP in the oceans.

A

iron

53
Q

Iron _____ is scavenged more slowly than free Fe irons.

A

bound to ligands

54
Q

For our key nutrients (N,P,Si, and Fe) the main sources to the oceans are _____ and _________, and the main sink is __________.

A

rivers
aerosol deposition
burial in the sediments

55
Q

Recently is has been shown that the hydrothermal vents (where the heated waters come out of the sediments are also strong ______ to the oceans.

A

sources of iron

56
Q

Rivers are a source of ___ to the oceans in the form of bicarbonate ions resulting from the weathering of rocks on the continents.

A

DIC

57
Q

The riverine sources of N and P have more than doubled since preindustrial times due to

A

fertilizer runoff (N and P)
fossil fuel burning
N emissions and subsequent deposition
runoff (N)

Ocean Biogeochemistry (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions