Brainstorm It is a scientific fact that the Earth heats unevenly. What evidence can you give to support this idea? What factors do you think cause the Earth to heat unevenly?

Evidence? Seasons! If the sun were to heat the Earth evenly, there would be very little change in temperature over the course of the year.

4 Factors that Cause the Earth to Heat Unevenly: Earth is spherical (light from a single source won’t strike a sphere evenly) Earth’s axis of rotation is tilted 23.5 degrees Distance between Earth and sun varies with time of year Earth’s orbit isn’t circular, it’s slightly elliptical (more heat when closer to sun)

Video Clip As you watch the 6 minute clip, answer the following question: How does the ocean influence weather and climate?

How is the ocean a driving force for weather and climate? The ocean stores more heat than the atmosphere el Niño and la Niña Changes in water temp affect humidity in the air which steers storms in certain directions Warm water from the Gulf is carried in the Gulf stream causing areas in Europe to be warmer Hurricanes

Map Activity Accurately draw and label the Equator, Tropic of Cancer and Tropic of Capricorn on your map.

Directions Cont’d In pencil, draw and label the 7 major ocean currents indicating direction of the current West Wind Drift (a.k.a. the Antarctic Circumpolar Current) East Wind Drift (Antarctic Coastal Current/Antarctic Subpolar current) North Equatorial Current South Equatorial Current Peru Current Kuroshio Current Gulf Stream

Directions Cont’d Using a hot color and a cold color, indicate on the map (by tracing over your pencil lines) whether each current is a warm water current, cold water current, or contains both

Currents of the World

Fact vs. Fiction: What does Finding Nemo teach us about ocean currents?

What is a current? The “motion of the ocean” A steady flow of water within a larger body of water Surface currents and deep currents

Why are Currents Important? Moderate climates Mix nutrients and add oxygen Transportation (larvae, nekton, boats, etc.)

Based on Your Map: How Do Ocean Currents Differ? Direction of flow Relative Temperature Velocity

Demonstration Surface Currents Materials Plate 400mL of Water Cinnamon Sand Straw

How do the following 3 Factors Drive Ocean Currents? 1. The rise and fall of the tides 2. Wind 3. Thermohaline circulation

1. The rise and fall of the tides Tides create a current (called “tidal currents”) in the oceans, near the shore, and in bays and estuaries along the coast. They are the only type of currents that change in a very regular pattern and can be predicted for future dates.

2. Wind Winds drive currents that are at or near the ocean's surface. Measured in meters per second or in knots 1 knot = 1.85 kilometers per hour or 1.15 miles per hour Locally - winds drive currents near coastal areas Globally – winds drive currents across the open ocean

3. Thermohaline Circulation (aka Global Ocean Conveyor Belt) A process driven by differences in water density due to temperature (thermo) and salinity (haline) variations in different parts of the ocean. Can be deep or shallow Move much slower than tidal or surface currents.

Surface Currents

Video Clip Bob Ballard Analogy https://www.nationalgeographic.org/media/ocean-currents-and-climate/

What is the Coriolis Effect? The tendency for wind-driven surface currents to deflect to the right in the N. Hemisphere and to the left in the S. Hemisphere Caused by the Earth’s rotation *Video Clip

What is a Gyre? The circular flow of currents in an ocean basin due to the Coriolis effect