Unit 8 Flashcards
What drives surface ocean currents?
Surface winds drive ocean currents. ## Footnote Trade winds and westerlies set major ocean currents in motion.
What is the Ekman Spiral?
The Ekman Spiral is the result of the Coriolis force, where each deeper water layer moves at an increasing angle from the wind direction.
What is the Coriolis force? .
The Coriolis force causes ocean currents to be deflected. ## Footnote It deflects currents to the right in the Northern Hemisphere and to the left in the Southern Hemisphere
How do surface winds affect ocean currents?
Surface winds drive ocean currents in patterns similar to atmospheric high-pressure system
What is Ekman Transport?
Ekman Transport is the net movement of water that is 90° to the right (NH) or left (SH) of the wind direction.
How does the shape of the ocean basin influence currents?
The shape of the ocean basin, including coastlines and underwater ridges, influences where gyres, boundary currents, and upwelling occur.
What are Subtropical Gyres?
Subtropical Gyres are high-pressure zones that create clockwise (NH) and counterclockwise (SH) ocean circulation.
What is geostrophic circulation?
Geostrophic circulation occurs when Ekman Transport moves surface water toward the center of ocean basins, creating a pressure gradient force that balances with Coriolis.
What causes equatorial upwelling?
Equatorial upwelling occurs when strong trade winds cause water to diverge at the equator, leading to the upwelling of cold, deep water.
What is coastal upwelling?
Coastal upwelling is when wind-driven Ekman transport moves surface water away from the coast, drawing cold, nutrient-rich deep water upward.
What is coastal downwelling?
Coastal downwelling is when wind-driven Ekman transport moves surface water toward the coast, pushing warm water downward.
What is the thermocline?
The thermocline is a layer of ocean water where temperature changes rapidly with depth.
How does downwelling affect the thermocline?
Downwelling forces warm water downward, deepening the thermocline.
How does upwelling affect the thermocline?
Upwelling brings cold water to the surface, making the thermocline shallower.
What drives thermohaline circulation?
Thermohaline circulation is driven by differences in temperature (thermal) and salinity (haline).
What happens to cold, salty water at high latitudes?
Cold, salty water sinks at high latitudes, driving deep ocean currents.
