Ocean currents map illustrating major surface currents in the Atlantic and Pacific Oceans, highlighting the North and South Equatorial Currents.

Final Answer:
1. They are named after the regions or directions where they flow (e.g., North Equatorial Current flows near the equator in the northern part of the ocean).
2. The Gulf Stream.
3. Warm currents bring warm air, which increases temperature and humidity, often leading to more rain and milder winters.
4. Wind (especially trade winds and westerlies), Earth’s rotation (Coriolis effect), and differences in water density (due to temperature and salinity).
5. The Gulf Stream and the Labrador Current — because the Gulf Stream brings warm water from the south and the Labrador Current brings cold water from the north, creating strong contrasts in temperature and weather along the U.S. East Coast.
6. They usually sink (downwell) because cold water is denser than warm water.