Osmosis (Revisited) Video

Density mass per volume of seawater Determined by temperature and salinity Density of seawater increases all the way to its freezing point of -1.9 º C

Pressure

Light

Oceanic Circulation Surface –Wind Driven currents, waves and tides Deep Sea Currents –Thermohaline Circulation (Oceanic Conveyor Belt) Waves Tides

Atmospheric Circulation Atmospheric conditions lead to the development of winds –Less dense air rises causing a low pressure –Heavier air sinks causing a high pressure

Atmospheric Circulation

Coriolis Effect Earth’s rotation changes speed depending on the latitude –Greatest at the equator (1674 km/hr) –Smallest at poles (0 km/hr) N. Hemisphere – Deflects motion to right S. Hemisphere – Deflects motion to left

Coriolis Effect

Salinity

Temperature

Surface Currents: Wind Driven Wind imparts energy –Speed –Fetch (distance over which wind blows) –Duration Coriolis force deflects currents –Northern Hemisphere: deflection to right –Southern Hemisphere: deflection to left Geography affects currents

Beaufort Wind Force Scale (NOAA) Force 0 Force 2 Force 7Force 11

Surface Currents: Wind Driven Wind imparts energy –Speed –Fetch (distance over which wind blows) –Duration Coriolis force deflects currents –Northern Hemisphere: deflection to right –Southern Hemisphere: deflection to left Geography affects currents

Beaufort Wind Force Scale (NOAA) Force 0 Force 2 Force 7Force 11

Winds and the Resulting Ocean Flow

Ekman Spiral

Major Surface Currents of the Oceans

Thermohaline Circulation Deep Currents are density related –As water gets colder and more saline it sinks –Downwelling Areas: where water sinks –Upwelling Areas: where water rises to surface Conditions at surface determine the temperature and salinity of water –Density determines the depth to which the water sinks

Atlantic Deep Water Formation

The Oceanic Conveyor Belt