Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
47 Cards in this Set
- Front
- Back
|
why ocean circulation is important? |
-transport 20% latitudinal heat from equator to poles -transport organism and nutrients -influences in weather and climate |
|
|
-Typesof ocean circulation/currents |
-surface current -deep current |
|
|
-surface current driven by___ and its motion is ___ |
--driven by winds cause by - earth rotation and -ocean basin -horizontal motion |
|
|
the deep current driven by ____ and its motion is _____ |
-driven by density-cause by diff tempt, salinity -vertical and horizontal motion |
|
|
how current by winds created? |
-force of the wind exerting stress on the ocean surface -the stress cause the water to move |
|
|
Do strength of the wind determining thespeed of the current ?
|
yes |
|
|
Does a wind-driven current flow in exactly the same direction as the wind, ?
|
does not
-but is deflected by Earth’s rotation |
|
|
Earth’srotation thedeflecting force called?
|
(Coriolis force)
|
|
|
________________ greater at high latitudes and more effective in deep water
|
coriolis force
|
|
|
where is the direction of coriolis force at northern and southern hemisphere |
S=left N= right |
|
|
what is equatorial currents |
the resulting currents from Trade winds |
|
|
Trade winds deff.
|
a wind blowing steadily toward the equator from the northeast in the northern hemisphere
|
|
|
where the equatorial travel along the equator? |
westward |
|
|
what is a gyre? |
- a spiral; a vortex.
Currentsform large oceanic gyresthat rotate clockwise in the north and counterclockwise in the south |
|
|
what is ekman spiral ? |
-Describes the
speed and direction of flow of surface water at -various depths. |
|
|
at north hemispherehow the gyre rotate ?
|
rotate clockwise in the
|
|
|
the south hemisphere how the gyre rotate?
|
counterclockwise in
|
|
|
how layer below defleated by corriolis effect ? |
below layer move to right of the over laying layer |
|
|
why deeper layer move slowly? )ekman spiral) andatcertain depths the current may flow in the opposite direction to that of thesurface |
-eng. lost each transfer btwn layer |
|
|
ekman spiral are caused by |
wind blowing at the surface and modified by coriolis eff. |
|
|
why there no fully developed Ekman spiral
|
winds generally not constant enough to produce
|
|
|
Whenequatorial currents reach western portion, they must turn because ?
|
they cannot cross the land.
|
|
|
Thecoriolis effect deflects these currents awayfrom the Equator as Western boundaryCurrents
eg– the Gulf Stream and Brazil current |
=Warm currents
|
|
|
Whencurrent flow back across the ocean,Corioliseffect and continental barriers turnthemback toward equator as eastern Boundarycurrent
=eg- àCanary and Benguela current |
Cold currents
|
|
|
list 6great surface current circuits
|
=North Atlantic Gyre
=South Atlantic Gyre =North Pacific Gyre =South Pacific Gyre =Indian Ocean Gyre (Southern Hemisphere) =Antarctic Circumpolar current (West Wind Drift) |
|
|
def. of equatorial counter current |
Alarge volume of water is driven westwarddueto the north & south equatorial currents
|
|
|
why coriolis eff. is minimal near equator ECC-equatorial counter current |
-Water is not turn toward higher latitudes
-It piles up at the western margin -Causes average sea level on western side rise as mush as 2 meters than the eastern side -Water on the western margins flows downhill under gravity influence creating narrow ECC -ECC flow to east between equatorial currents |
|
|
do average sea lev. on western side rise as mush as 4 meters than eastern side |
no, only 2 meter
|
|
|
characteristic of upwelling |
-Verticalmovement of cold, deep, nutrient rich water to the surface
-Bringchilled water to the surface -Thiscold water rich in nutrients -Createhigh productivity |
|
|
what is the relationship of upweling and el nino |
during el nino there are lack of upwelling |
|
|
charateristic of downwelling |
-Mustlower surface productivity
-Carriesdissolved O2 to organisms living on the deep ocean floor |
|
|
why we called upwelling divergence surface water. |
Surfacewater move away from an area onTheocean’s surface
=Commonalong Equator =Especiallyin the Pacific (called equatorial upwelling) |
|
|
why we called downwelling convergence surface water. |
Currentmove toward each other
= eg.GulfStreams and Labrador, and E. Greenland =Waterstacks up, no place to go but downward |
|
|
how to measure surface current? |
-direct method-floating meter (lagrangian: float with current) •Intentional •Unintentional –Propeller meters (eularian: stay in one place) -indirect method - satellite, pressure gradient,doppler flow meter |
|
|
what is lagragian |
float meter that float with current |
|
|
what is eularian |
float meter that stay in one place |
|
|
what is thermohaline? |
a part of the large-scale ocean circulation
=deep ocean circulation |
|
|
where is thermohaline circulation happen |
below pynocline(density) -90% of ocean water circulation |
|
|
what is cause of thermohaline circulation |
difference in density temperature-salinity -slow velocity = –Cooler& saltier seawater is denser than warmer and fresher seawater |
|
|
where thermohaline circulation originate from? |
higher latitude surface ocean |
|
|
what is conveyor belt? |
deep water circulation =combination of deep water and surface currents |
|
|
North Atlantic Deep Water Comesfrom
|
Southeastern Greenland, Labrador Sea and Mediterranean Sea
=Like Antarctic Bottom water, it spreads throughout the Indian and Pacific Oceans =It is less dense =It layers on top of the Antarctic Bottom water |
|
|
atlantic ocean circulation |
|
|
|
What possibly bad could happen if there are Changesin thermohaline circulation?
|
-can cause global climate change
–Example, warmer surface waters less dense, not sink, less oxygen deep ocean |
|
|
northern pacific ocean convenyor belt |
Nosource of Northern Hemisphere deep water
=Lowdensity of surface prevent sinking to the deep ocean՚ |
|
|
Northern Indian ocean -convenyor belt
|
Water too warm to sink
|
|
|
do Warmwater dissolved more oxygen than cold water?
|
Cold water dissolved more oxygen than
|
