Inrto to Ocean Chem

What can isotopes tell us?
Isotopes can provide clues
about the chemical/physical
state of the ocean in
times past
why is Isotope labeling experiments useful?
because studying feeding habits and
tracing biological transformations.
Mass spectrometry
How isotopes measured
Heavy isotope tends to stay in the phase where it is most tightly bound
Source and cycling of carbon
Trophic levels of food webs
Tracer of water mass source
Temperature of formation of CaCO3
Changes in sea level due to storage
of water on land (as ice)- Glacial
Bonds formed by the ________ isotope are more readily broken than bonds involving the ________ isotope
light, heavy
The equilibrium fractionation of isotopes is always temperature dependent.
Oxygen isotopes in paleothermometry
What is Rayleigh Distillation?
When water evaporates from the surface ocean
the isotopic fractionation between the liquid the vapor becomes more pronounced and the remaining
vapor is very ________.
A progressive enrichment in ?15N and
?13C is also observed as you move up through trophic levels
Size distribution is a continuum, with the most particles at the smallest sizes.
“Suspended” Particles
you can use Pumps, small particles (< 70 µm)
“Sinking” Particles
Traps, collect bulk sinking material at different depths
Carbon flux __________ with depth due to decomposition
Mass flux peaked in March after the spring bloom and rapidly decreased with time. Summer fluxes were much lower
Time-Series Traps
POC is what?
Percent of Organic Carbon
what is the major control on the acidity of seawater?
Carbon dioxide
Long-term trends…
are greater than the large seasonal
How do we estimate the extent of anthropogenic CO2 in the ocean?
– Air-sea gas exchange (solubility pump)

– Photosynthesis, respiration & remineralization (soft-tissue pump)

– Formation & dissolution of particulate carbonate (carbonate pump)

How do we estimate the extent of anthropogenic CO2 in the ocean using d13C ?
-the concentration of atmospheric CO2,
changes in the…
-the d13C of atmospheric CO2,
-the d13C value of DIC in the ocean.
If CO2 dissolved in seawater without reacting, ~__% would remain in the atmosphere. Instead only ~ __% does.
70%, 55%
Saturation state is …
the thermodynamic condition of seawater that describes the degree of supersaturation or undersaturation with respect to the particular phase of the CaCO3 mineral
What are Some carbonate organisms?
Coral, caccolithaphorids, foraminifer, etc.
What are Coccolithophores?
Coral calcification rates may be reduced by __% – __%
What will decreasing pH do in the ocean?
ruin Coral reef habitats
Reasonably Achievable Emission Reductions
Redfield ratio(modified RKR)
P : N : C = 1 : 16 : 106


Particulate organic carbon
Dissolved organic carbon
Alpha (a) decay –
Nucleus emits 4He nucleus: mass decreases by 4, atomic number decreases by 2
Beta (b) decay –
Neutron converted to proton with emission of an electron: mass unchanged, atomic number increases by 1
Gamma (g) decay –
Electromagnetic radiation emitted as nucleus falls into lower energy state: no change in mass, generally accompanies other decays
Tritium-Helium Age
(~300 m)
Most important acid:
CO2(aq) or H2CO3
Most important base:
Most important base:
Arrhenius definition (traditional)
Acid: A substance that can produce H+ions
Bases: A substance that can produce OH-ions
Bronsted–Lowry difinition
Acid: proton donor
Base: proton acceptor
Lewis definition
Acid: (Lone electron pair acceptor)
Base: (Lone electron pair donor)