Term
| dissolved silica in the ocean exists in what form? |
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Definition
| dissolved silica exists as silicic acid |
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Term
| where is most silica in the world's oceans "trapped" |
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Definition
| most silica in the world's ocean is trapped below 60 degrees south latitude |
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Term
| 5 factors that effect rate of silica dissolving: |
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Definition
1. concentration of dissolved silica in the water
2. rain rate
3. temperature
4. surface area of crystals
5. pressure |
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Term
| silica is more soluble in surface water due to two factors, what two factors are these and which dominates? |
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Definition
| higher solubility of silica in surface waters is mostly due to higher temperature, pressure does play a smaller role |
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Term
| what is one factor that helps, but doesn't totally explain the trapping of silica in the southern ocean? |
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Definition
| a high iron concentration could lead to more efficient silica uptake by microorganisms |
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Term
| what did we examine about nitrate in the thermocline, and what did the findings teach us? |
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Definition
| we examined the preformed concentration of nitrate and saw that most of the nitrate in the thermocline is preformed, meaning it came from the surface where the current that makes up the thermocline formed |
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Term
| where are two places where silica ISN'T depleted along the thermocline? |
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Definition
| silica isn't depleted along the thermocline in the polar oceans and the north pacific |
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Term
| about what percent of silica exported gets to ocean floor? what happens to the rest? |
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Definition
| about 25% of silica exported gets to the ocean floor, the rest gets dissolved |
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Term
| what correlates to silica making it to the ocean floor? |
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Definition
| a high rain rate correlates to silica making it to the ocean floor |
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Term
| where do the nitrate-rich, silica-poor waters of the thermocline come from? |
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Definition
| the nitrate-rich, silica-poor water of the thermocline originate from surface waters between 60 and 40 degrees south latitude |
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Term
| what areas does the silica-poor thermocline affect? |
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Definition
| all of the atlantic and all of the pacific except the north pacific, |
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Term
| what two factors define vertical movement of water in polar oceans? |
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Definition
1. no thermocline, good vertical mixing
2. current convergence/divergence partially determine areas of upwelling |
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Term
| what drives the water in the 40-60 degrees south range downards to form the thermocline? |
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Definition
| downwelling of the water in the 40-60 degrees south range is caused by current convergence |
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Term
| where is the only one place where nutrient rich water from below the thermocline makes it to the surface to allow for diatom production, and why is it like this? |
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Definition
| in the north pacific, a shallow thermocline and good vertical mixing brings deep nutrients into the thermocline |
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Term
| what is the pH of the ocean? why does it stay so constant? |
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Definition
| the pH of the ocean is 8.1, it stays so constant because of the carbonate buffering system |
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Term
| what does H2CO3* signify? |
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Definition
It is a term that lumps together partial pressure of CO2 with concentation of H2CO3
CO2 (g)↔ H2CO3*, rate constant for equilibrium is K0
K0 = [H2CO3]/(pCO2(g)) |
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Term
| what is K1 in carbonate buffer |
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Definition
K1
=
([H+][HCO3-])/[H2CO3*]
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Term
| what is K2 in carbonate buffer? |
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Definition
K2
=
([H+][CO32-])/[HCO3-] |
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Term
| what are all molecules that contribute to DIC? |
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Definition
DIC
=
[H2CO3*]+[HCO3-]+[CO32-]
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Term
| when we calculate DIC and Alk, we discount less significant values, leaving us with simple, easy to understand equatiosn for DIC and Alk. What are theses equations? |
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Definition
DIC=[HCO3-]+[CO32-] we discount [H2CO3*] because it is insiginficant
Alk=[HCO3-]+2[CO32-] |
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Term
| what is the equation for [HCO3-] in terms of DIC and Alk? |
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Definition
|
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Term
| what is the equation for [CO32-] in terms of DIC and Alk? |
|
Definition
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Term
| what is the most useful equation for pCO2 in the ocean? it requires simplifying assumptions |
|
Definition
pCO2
=
(K2)/(K0•K1)
•
(2DIC-Alk)2/(Alk-DIC) |
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Term
| what factors can change pCO2 other than changes in DIC and Alk? |
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Definition
changes in temperature and salinity change pCO2 by affecting K0, K1, and K2
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Term
| rise in temperature has what effect on the K's in the pCO2 equation? what effect does this have on temperature? |
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Definition
rise in temperature majorly decreases K0, increases K1, and increases K2.
This has the overall effect of increasing pCO2 |
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Term
| what effect does photosynthesis have on Alk and why? |
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Definition
| photosynthesis increases Alk by pulling H+ ions out of the water |
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Term
| why does opal have a greater overall export rate than organic carbon? |
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Definition
| becuase of the tendency for OM remineralization to beat of Opal dissolution at lower temperatures |
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Term
| summarize sediment deposition of Opal |
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Definition
| Opal makes it to sediments even though the vast majority of water in the ocean is undersaturated with silica. |
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Term
| what is the global average of the percent of silica exported that ends up being deposited? |
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Definition
| 59% of total opal exported is deposited |
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Term
| what percent of sun's energy coming at earth is reflected? |
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Definition
| 30% of energy coming at the earth from the sun is reflected? |
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Term
| equation for amount of energy from sun absorbed by the earth, has three parts |
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Definition
| pi*r2 * (sun's energy in watts/m2)*.7 |
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Term
| if temperature of the planet is unchaging, what equals what? |
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Definition
if temperature of planet is unchanging, energy being absorbed by the earth equals energy emitted from the earth
σ*T4*4*pi*r2 = pi*r2*(1367watts/meter2)*.7 |
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Term
| equation for energy emitted by earth |
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Definition
| 4*pi*r2(surface area of a sphere)*T4*σ |
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Term
| what determines if a gas will absorb heat energy and convert it into vibrational energy? |
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Definition
| if a gas is assymetrical or is generally more complex than a simple diatomic molecule, then it will vibrate more and thus absorb heat energy |
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Term
| what gas contributes the most to the greenhouse effect? |
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Definition
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Term
| what do CO2, CH4, H2O, etc absorb heat energy whereas N2 and O2 barely do? |
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Definition
| assymetrical or more complex molecule convert heat energy to vibrational energy, diatomic molecules tend not to |
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Term
| global warming potentional is a measurement of what? higher global warming potential for a gas means what? |
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Definition
global warming potential is a measurement of a molecule's ability to act as a greenhouse gas relative to CO2's ability to act as a greenhouse gas.
Higher global warmning potential means more greenhouse effect from that gas |
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Term
| what three factors decide a molecule's global warming potential? |
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Definition
1. lifetime in atmosphere
2. ability to absorb heat
3. quantity |
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Term
| what do we call the assesment of how a gas will contribute to global warming? |
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Definition
|
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Term
| methane is 60 times better at abosorbing heat than CO2 but methane doesn't have a global warming potential that is sixty times as high as CO2's, why? |
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Definition
| becuase methane has a shorter lifetime in the atmosphere |
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Term
| why does global warming potential drop over time? |
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Definition
| global warming potential drops over time because the gas degrades |
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Term
| as we release more anthropogenic CO2, does it spread out evenly between oceans and atmosphere? |
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Definition
| of the the CO2 that we emit, a higher percentage goes to the atmosphere than the ocean |
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Term
| as CO2 in atmosphere increases, effeciency of ocean as carbon sink ____ |
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Definition
| as CO2 in atmosphere increases, effeciency of ocean as carbon decreases |
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Term
| for every pentagram of mineral CaCO3 that sinks from the euphotic zone, how much dissolves before it reaches the deep ocean |
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Definition
| .5 pentagrams of all mineral CaCO3 that sinks from the euphotic zones dissolves before it reaches the deep ocean |
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Term
| for every pentagram of CaCO3 that makes it to the deep ocean, how much is buried? |
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Definition
| for every pentagram of CaCO3 that makes it to the deep ocean, .26 pentagrams are buried and .74 pentgrams dissolve back into the ocean |
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Term
| for every pentagram of mineral CaCO3 that is produced, how much ends up where? |
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Definition
| .5 pentagrams dissolve before the deep ocean, .13 are buried, and .37 dissolve in the deep ocean |
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