Do Meow What causes ocean currents Think about

Do Meow What causes ocean currents? (Think about the demonstration we did with the thyme, candle, and cooking oil)

Announcements • Please copy your homework • You have 8 words to define this week and you will be tested on them THIS WEEK Deep Current Gyre Surface Current Tradewinds Coriolis Effect Polar Easterlies Jet Stream Westerlies Check this out

Image from flikr, https: //www. flickr. com/photos/fdecomite/6890267408/ The Influence of Ocean Currents It all begins with the sun……

OCEAN CURRENTS • Mass movement or flow of ocean water • River within the ocean • Two types: – Surface and Deep Image from pixabay, https: //pixabay. com/en/sea-beach-wave-north-sea-water-250527/

Ocean Currents Surface Currents The upper 400 meters of the ocean (10%). Deep Water Currents Thermal/Salinity currents (90%) Image from Wikimedia, https: //commons. wikimedia. org/wiki/File: Corrientes-oceanicas. png Image from Wikimedia, https: //commons. wikimedia. org/wiki/File: Ocean_circulation_conveyor_belt. jpg

Surface Currents Link Horizontal, stream-like movements of water that occur at or near the surface of the ocean • Can reach depths of several hundred meters • Example: Gyres

Surface Currents • Controlled by three factors –Global winds –Coriolis Effect –Continental Deflections

Surface Currents • Global Winds –Cause surface currents to flow in the direction the wind is blowing –EX: Jet Stream • Coriolis Effect Link –The apparent curving of moving objects due to the Earth’s rotation

Surface Currents • Coriolis Effect –Northern Hemisphere = clockwise –Southern Hemisphere = counter clockwise • Continental Deflections –Shape of continents change the direction of current flow

Deep Currents • Stream-like movement of ocean water far below the surface • Caused by – Changes in density – Change in temperature – Change in salinity Image from Wikimedia, https: //commons. wikimedia. org/wiki/File: Antarctic_bottom_water. svg

What Affects Deep Currents? • Change in temperature –Decreasing the temperature of water increases density • Change in salinity (demonstration) –Increasing the salinity of water increases density

Currents and climate • Warm water currents –Bring warm water to colder regions Image from Wikimedia, https: //commons. wikimedia. org/wiki/File: Golfstrom. jpg

Currents and climate • Cold water currents –Bring cold water to warmer regions Image from NOAA, http: //www. ospo. noaa. gov/data/sst/contour/californ. cf. gif

Why are Ocean Currents Important? • They make the average temperatures of climates more similar – This is on a large scale • Ocean air holds a lot of water vapor – so there is more rain at the coast • Currents redistribute heat throughout the globe – Example: Gulf Stream brings warm air into England, making it warmer