Hydrosphere: Oceans

Ocean Currents

In this activity, students will learn the pattern of major ocean currents and how they are changed by wind, land and water.

Ocean Currents Change Our Earth

Ocean currents — the continuous, directed movement of ocean water — affect regional climates and alter the biological and chemical characteristics of seawater.

Properties of Fresh Water and Sea Water

The students will set up three demonstrations to observe the properties of water. They will explore the boiling point of water, the freezing point of water, and the ability of water to store heat. These activities can be done individually or as a set.

Sea and Ice Salinity

What is sea ice? It is simply frozen ocean water. Why is sea ice important? While it occurs mainly in polar regions, sea ice influences our global climate. Changing amounts of sea ice can affect ocean circulations, weather patterns, and temperatures around the world. Sea ice insulates the relatively warm ocean water from the cold polar atmosphere, except where cracks in the ice allow for the exchange of heat and moisture. The exchange of salt between sea ice and the ocean alters the density of ocean waters, thus influencing ocean circulation. Many animals, such as polar bears, seals, and walruses, depend on sea ice for their habitat. These species hunt, feed, and breed on the ice. Satellites provide the best way to observe sea ice, the factors that affect sea ice, and the ways sea ice affects global climate. Scheduled to launch in 2010, NASA’s Aquarius mission will measure global sea surface salinity with unprecedented resolution. Even small variations in sea surface salinity — the amount of salt present near the ocean’s surface — can have dramatic effects on sea ice, the water cycle, and ocean circulation.

Sea Level and the Terrapin

This activity from the Environmental Protection Agency will give children the opportunity to see how changes in sea level effect coastlines, animal life, and community development.

Splish Splash

Crucial to our existence, water sustains all life on Earth. Following the old adage, "What goes around comes around," water moves continuously through the stages of the hydrologic cycle (evaporation, condensation, and precipitation). How does our drinking water fit into this hydrologic cycle? Where did the water we drink fall as precipitation? Did this water percolate down into the ground as part of a groundwater system, or did it remain on the surface as part of a surface water system? What path did this water follow in order to become our drinking water? This lesson will explore the hydrologic cycle and water's journey to our glass.

The Great Ocean Conveyor

Learn about ocean currents and systems in this activity from NOAA.

Water: A Never-ending Story

Water on earth is used over and over. The water cycle, the continuous movement of water from ocean to air and land then back to the ocean in a cyclic pattern, is a central concept in meteorology.

Your Own El Nino

Every two to seven years, trade-winds in the Pacific Ocean slow down or reverse their direction — no one is sure why. But when the trade winds slow down, everything changes. Water temperatures become warmer in the eastern Pacific and colder in the west. Nutrient upwelling slows, and fish populations become much smaller along the Pacific coast of South America. Rainfall follows the warmer water, causing flooding in Peru and drought in Indonesia and Australia. Because these changes can be highly destructive, advance warning of El Niño’s approach is important for emergency preparation. NOAA satellites are constantly collecting information on sea surface temperatures around the globe. NOAA also operates a network of buoys that measure temperature, currents, and winds in the tropical Pacific Ocean.


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