Salinity, Temperature, Density ↓ temp = ↑ density ↑ salinity = ↑ densit Thermocline –Zone of rapid temp decrease –Does this correlate with density and salinity?

Below the surface waters (>500m) it is cold, dense, and saline. Surface water is effected by wind, currents, latitude, and land masses.

Colder at the poles; warmer at the equator (upto nearly 30 C)

Gas O, CO 2, N Dissolve better in ↓ temp ↑ gas concentrations at poles O not very soluble;.4-.6% –Compared to 21% in air CO 2 is more soluble; 80% –Compared to.04% in air –Ocean stores 50x more CO 2 than air

Light Blue wavelengths penetrate the furthest Suspended and dissolved particles affect penetration –Coastal waters absorb some blue Appear more green

Pressure 1 atm = the weight of all the air above Every 10m of water depth adds 1 atm Increases gas compression (↑ gas density = ↓ gas volume) …not so good for swim bladders

Surface Circulation Wind drives currents Both are driven by sun/heat Both are affected by Coriolis effect –Curved path due to earth’s rotation N of Equ. deflects to the right S of Equ. deflects to the left

Wind Driven by heat ↑ temp = ↓ density …air rises …air from higher latitudes move in place making wind…bent by coriolis effect Northeast trades Westerlies

Wind pushes surface water …bent by Coriolis, too Together gyres are produced –Large circular surface current systems –Move heat from equ. to higher latitudes

Wind causes waves, too. Floating objects move in circles rather than following the wave

Wind pushes surface water Wave settles into circular swells Waves nearing shore run out of space for circular motion…piles up…crashes

Tides Recurring rise and fall of sea surface caused by gravitational pull & rotation Moons gravity pulls water towards moon ↓ gravitational pull on opposite side is not enough to counter the outward inertia of earth’s rotation

Earth rotation = 24 h –High bulge –2 highs & 2 lows in a 24 hr period Moon has own orbit –Therefore, full tidal cycle = 24 hrs, 50 min.

Sun also has gravitation pull…its larger mass would = much stronger pull, but its much further away…therefore half the pull of the moon When both are aligned with earth, grav. pull is additive = higher highs & lower lows = spring tides

Diurnal = daily; once in 24 hours Semi = half; semidiurnal = _____ –US east coast US west coast has mixed or variable high & low tides every half day…due to effects of bottom topography and other land masses