lecture 3 cards Flashcards
(50 cards)
Coriolis effect
Points at different latitudes on the earth’s surface rotatee at different velocities, currents in N. hemisphere move clockwise and in s. hemisphere move counterclockwise
Prevailing winds, north to south
Polar easterlies, westerlies, northeast trade winds, southeast trade winds, westerlies, polar easterlies
Air cells, from north to south
Polar cell, Ferrel cell, Hadley cell, Hadley cell, Ferrel cell, Polar cell
Eckman spiral
wind drives the surface water in a direction 45 degrees to the right of its path. Deeper waters continue to deflect to the right but move at a slower speed. **net water movement is at right angles to the wind direction
Low pressure system spirals
in Northern Hemisphere, cyclonic circulation around low pressure system, anticyclonic circulation around a high pressure system
Cyclonic
counter-clockwise
Anticyclonic
clockwise
Upwellings
Water moving vertically upwards under areas of low pressure. Brings nutrients to the surface, creates areas of high primary productivity.
Downwellings
Water moving vertically downwards under areas of high pressure. Restrict the supply of nutrients and cause areas of very low productivity.
Gyres
Large circular patterns of water movement because of coriolis effect, upwellings in the middle so there is water piled up in the center, gravity pulls the water downhill, creating a geostrophic current
Oligotrophic
Not much food available
Langmuir circulation
Small scales of circulation, mixes plankton organisms in the surface region, driven by the wind
Coastal upwellings
Upwellings along continental margins, on scales of 100s of kilometers
Ekman transport
Carries surface water away from continental margins, upwelled water replaces the water that moved away
Equatorial upwellings
created by the coriolis effect, drives water away from the equator and creates upwelling
Gulf Stream Eddies
large eddies formed by the gulf stream. North of the stream, eddies are warm and rotate clockwise, south they are cold and rotate counterclockwise
NADW
North Atlantic Deep Water, cold and salty, very dense, sinks and travels south
ABW
Antarctic Bottom Water, more dense than NADW, forces NADW to the surface
MOC
Meridional Overturning Circulation, thermohaline circulation or conveyor belt
Spring tides
When sun and moon are aligned, highest highs and lowest lows
Neap tides
When sun and moon are at 90 degree angles to each other, producing lower than average amplitudes of tides.
Semidiurnal tidal cycles
Twice per day
Diurnal tidal cycles
Typical, once per day
Mixed tidal cycles
Large land effect. One higher high water, a lower high water
