Flashcards
oceans
Cards in this deck (29)
- 1What do ocean currents do?Affect weather and climate, distribute nutrients, and move organisms around
- 2What are surface currents driven by? thermohaline currents? What are the flow of surface currents around the edge of the ocean basin called?-winds
-density differences (salinity and temperature)
gyre - 3North Atlantic Gyre Subdivided into how many currents? with distinct what4
flow speeds and temperature - 4What is an Ekman spiralWind driven current. Topmost water layer driven by Coriolis effect.
Layer underneath moved by water above
Each lower level is slower - 5Ekman transportnet result of Ekman spriral
90 degrees, to the right of wind in NH, left in southern - 6Why does gyre form?water piled up in centre. Gravity causes pressure gradient downhill
Balance of Coriolis effect and pressure gradient holds gyres along outside edges of ocean basins - 7What is a boundary current? What is a Western boundary current?Currents that form gyres
narrow, fast, deep currents. Move large volume warm water towards poles - 8What is an EddiesTurbulent rings that separate from current meanders
- 9Boundary Currents Eastern boundary current? Transverse currents? West wind drift?eastern edge of ocean basins (5) carry cold water toward equator. Shallow and broad low flow
Due to trade winds
Unobstructed by continents. Carries more water than any other around Antarctica - 10Westward Intensification -When is the Coriolis effect stronger? -Water moving __ on N side of Atlantic Gyre turns sooner and stronger then water moving __ at equator - What does this mean?farther from equator
E, W
Peak of hill close to west side of brain - 11Westward Intensification Because slope of hill is steeper on Western side, current on western side must be what? Which is faster and narrower, Western or Eastern boundary's? by how much?concentrated an rapid for equal flow around gyre
Western, 10x faster, 20x narrower - 12Ocean Circulation Visualization In the real world, are circulation patterns tidy? When did NASA get visualizations of currents based on numerical model and observations?no
2005-2007 - 13Effect on weather and climate What does warm water flowing to higher latitudes transfer?heat
especially at mid latitudes - 14Vertical Movement of water Horizontal movement of waster due to wind can cause what? What is upwelling?vertical circulation
is upward movement of water. Brings cold nutrient rich water to surface - 15Equatorial Upwelling What is it? what replaces it?Water moving in currents on either side
of equator deflected slightly by Coriolis effect
Deep water - 16What does the Equatorial Up welling doBrings water with nutrients to surface, resulting in high biological productivity
- 17What can cause Coastal Upwelling? Where is it common?Wind blowing parallel to shore or offshore
California, perue
it also increases production of algae - 18El Nino (it's a very productive area) What does it result from? What does it do? What does it result in?-Changes in normal wind and current flow in tropical Pacific
-backs up and overrides northward flow of cool Peru current
-weakened equatorial current and movement of warm water back to east - 19What are the effects of El Nino?sea and water temperature rise
More evaporation= intensified storms and higher than normal rainfall inland
impacts on marine organisms
colder - 20Thermohaline Circulation What are they? due to what?-slow circulation of currents also occurs below pycncline. Responsible for large-scale vertical movement of ocean and global circulation of ocean
-density rather than wind energy - 21Water Masses Reminder: Ocean is stratified by what? Water masses have distinct what?density (densest water deepest)
temperature and salinity - 225 common water masses?surface water-200m
Central water- to bottom of thermocline
intermediate water- to about 1500m
deep water- to about 4000m
bottom water- in contact with seafloor
(Densest (deepest) masses formed when surface ocean becomes very cold&salty) - 23Formation of Deep water in polar regions What is the Antarctic bottom water? When does it form? What does it do with water from southern Antarctic circumpolar current? where does it spread? how long does it maintain identity?most distincitve water mass. Extreme density, large volume
during winter when ice freezes and salt concentrated
sinks and mixes with it
along deep-sea bed
1600 years - 24North Atlantic Deep Water most ___ water some escapes where? When does it form?dense
from deep channels in ridges separating Scotland, Iceland, Greenland
when warm water brought into North Atlantic Ocean by Gulf Stream cooled by winds - 25What happens when warm water is carried North by surface currents? What is a Global conveyer belt? What does the 1000 year circuit do?it loses heat and sinks to form deep and bottom water
it moves deep water from North Atlantic towards Southern Hemisphere. Wells up
distributes dissolve gases and solids, mies nutrients, transports organisms - 26Studying ocean currents How do we measure water movement?-flow method (fixed in 1 place)
current metres measure water flow by:
1)impeller movement
2) Acoustic doppler shift - 27What is the float method?object that floats with the current: flow speed from distance travelled/ unit time
- 28Deeper Ocean Currents What are swallow floats? How many floats are currently out? argo floats-
-survey intermediate water mass.
- Communicated through SOFAR channel
->3500 - 29What are other new tools?-slocum glider
- Chemical tracers
-Acoustical tomography
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- Flashcards on oceans, created by Courtney Sulliva on 23/02/2016.
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- Courtney Sulliva
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