14.3 Rivers in the SeaReading Guide

(Pages 469 – 470)

  1. What is the relationship between ocean currents and solar energy?

Water absorbs a lot of solar energy and distributes (spreads) the energy over the Earth.

  1. What “starts” ocean currents flowing?

Surface winds.

  1. What are the other two major factors that control the direction of currents?

Coriolis Effect (turns currents to the RIGHT in the N. hemisphere, LEFT in the S. hemisphere) and the shape of the continents

  1. Refer to Figure 14.17 on page 469. Using red and blue markers or pencils, colour code the warm and cold currents on your handout.
  1. List the currents in each of the major gyres listed below:
  2. North Atlantic Gyre (3)Gulf Stream, Canary, Northern Equatorial
  3. South Atlantic Gyre (3)Brazil, S. Equatorial, Benguela
  4. North Pacific Gyre (4)N. Equatorial, Kuroshio, N. Pacific, California
  5. South Pacific Gyre (3)S. Equatorial, East Australia, Peru
  1. Which side of gyres are normally cool?

Right

  1. Explain why coastlines near cool currents often have dry climates.

Cool air above the currents doesn’t hold as much water vapor, so onshore breezes don’t contribute any rain.

  1. Which side of gyres is normally warm?

Left

  1. How do warm currents affect the climate of nearby coastlines?

Bring warmer air (warmer climate) and more humidity (precipitation)

  1. Which current is the largest and travels farthest around the world?

West Wind Drift (just north of Antarctica)

Deep Currents P 471 (omit investigation)

  1. What two factors affect the density of sea water (causing it to rise or sink)?

Sea water is more dense if it is very cold or very salty (saline).

  1. What are two reasons why water in the Arctic is more saline (salty)?

As icebergs form, mainly fresh water turns to ice, leaving the salt behind.

Surface currents evaporate on their way to the Artic, so are more saline when they arrive.

  1. What is a deep ocean current and how is it different from a surface current?

It is a current that travels far below the surface (along the ocean floor) that is not affected by winds. (usually very cold and saline)

  1. How long is the trip for seawater on the “great ocean conveyor belt”?

It takes about a thousand years.

  1. What two things are transported through the ocean on the “conveyor belt”?

Heat and nutrients are distributed through the ocean.

  1. What negative consequences might happen if the ocean’s circulation was disrupted?

Currents might slow or even stop, changing climate drastically. (If the Gulf Stream did not bring warm water to Northern Europe, it might freeze, for example.)

El Niño (p 475)

  1. Explain the process of upwelling, which causes cool water to rise.

In areas where winds blow continuously toward the open ocean, cooler water is drawn upward to replace surface water that is pushed away.

  1. Describe the four main areas where upwelling occurs.

All four areas occur on the west coast of continents within or near the tropics.

  1. Why are areas of upwelling very productive?

In areas of upwelling nutrients are brought up from the bottom of the ocean, allowing more algae to grow and creating large food chains.

  1. What is an El Niño?

An El Nino is an event that results when the trade winds (in the tropics) become weaker and the Pacific Ocean becomes warmer off the coast of Peru and California. It causes dramatic changes in weather and fishing.

  1. Describe some of the global effects of an El Niño.

Dramatic changes in weather: increased numbers of typhoons in the Pacific, Flooding in South America (Ecuador, Chile, Peru), storms in western US and Canada, drought in Indonesia, Southern Africa, Australia

  1. Describe the TAO array and explain its purpose.

The TropicalAtmosphereOcean array is a series of 70 instrument buoys that collect data on ocean conditions and help monitor and predict El Niño events.