The Physical and
Chemical Properties of Water
The Water Molecule
•
H2O
- dipole structure
•
Hydrogen
Bonds
•
Solvent
power & high heat capacity
Changes of State
•
Temperature
and Heat
–
Average
kinetic energy versus total kinetic energy
•
The
physical states of water
–
Liquid,
solid, and gas
–
H
bonds = high heat capacity
–
Latent
heat of fusion
–
Latent
heat of vaporization
Other consequences
of H bonds
•
Cohesion
•
Surface
Tension
•
Viscosity
H2O
Density
•
1
g/cm3
•
Temperature
and density
•
How
does salinity influence density?
Transmission of
Energy
•
Heat
- Conduction, convection, radiation
•
Light
•
Visible
light
•
Refracted,
absorbed, scattered
•
Attenuation
•
How
far does light penetrate into the ocean
•
Photic
Zone
The Chemistry of
Seawater
•
Acidity
and alkalinity - H+ and OH-
•
pH
•
pH
of Seawater = 7.8
•
Why
is seawater buffered?
Salinity
•
Solvent
power
•
Disolved
ions
Salinity
amount of
dissolved ions in seawater..
-> normal
salinity = 3.5% or 35‰ parts per thousand (ppt)
Tropics =
lowest salinity->high precip.=> 34.5‰
Subtropics=highest
salinity ->high evaporation => 36‰
Why does this
surface pattern exist?
Salinity
•
Where does the salt come
from?
•
Why is salinity so
stable?
Chemistry of
Seawater
•
Major
constituents
•
Trace
elements
•
Conservative
•
Principle
of Constant Proportion
Chemistry of Seawater
•
Gasses
–
N2,
O2, and CO2
•
Why
are concentration of O2 high but CO2 low in the upper 100
m?
•
Why
does O2 reach a minimum between 200 and 800 m?
•
Temperature,
salinity, and pressure
CO2
and O2
•
The
Carbon Cycle
•
The
biological pump - deep ocean = carbon sink
•
The
Oxygen Balance
–
Photosynthesis
<=> Weathering
Nutrients
•
N,
P, and Si
•
Nonconservative
elements
•
Limiting
elements