The friction produced by winds blowing towards the equator on the ocean's surface, together with the effect of the earth's rotation, cause water in the surface layer to move away from the western coast of continental land masses. This offshore moving water is replaced by water which upwells, or flows toward the surface from depths of 50 to 100 meters and more. Users can view an illustration and read ... Full description.

The deserts of the world today are not the deserts of the planet's past. Fossilized hippopotamus and elephant bones tell us that the Sahara, for instance, was a much moister and more hospitable environment 8,000 years ago than it is now. Each of the Earth's modern deserts are a consequence of one of the following mechanisms: air mass subsidence, rain shadows, distant moisture sources, or cold offshore ... Full description.

This webpage is part of the University Corporation for Atmospheric Research (UCAR) "Windows to the Universe" program. It describes the nature and configuration of magnetic fields, which are the result of moving electric charges, including how they cause magnetic objects to orient themselves along the direction of the magnetic force points, which are illustrated as lines. Magnetic field lines by convention ... Full description.

This site, part of NASA's Classroom of the Future program, describes how oceanic temperatures, currents, and atmospheric pressure patterns vary and, under certain conditions, produce an ENSO (El Nino Southern Oscillation) event. It features text, scientific illustrations, a glossary, teacher pages, and a list of references. Full description.

This computer-generated animation depicts the Clouds and the Earth's Radiant Energy System (CERES) instrument in operation. CERES measures the energy at the top of the atmosphere and estimates energy levels in the atmosphere and at the Earth's surface. Using information from very high resolution cloud-imaging instruments on the same spacecraft, CERES also will determine cloud properties, including ... Full description.

The ocean and atmosphere continually exchange particles and gases in a kind of ongoing "dialogue" that influences regional and global climate. This site explains the chemical link between the ocean and atmosphere. Emphasis is on the ocean's ability to store and release water vapor and carbon dioxide, both of which contribute to the greenhouse effect. Features include text, a scientific illustration, ... Full description.

This site explains how temperature, pressure, and salinity work together to determine the density of ocean water. The three density layers of the ocean are described by means of text description and a graphic illustration. Full description.

This is part of the National Oceanic and Atmospheric Administration's National Data Buoy Center website. It features text descriptions, graphs, and graphic illustrations to describe the development of land and sea breezes because of the unequal heating rates of land and water. Full description.

This graphic illustration and accompanying text description show the distribution and relative proportions of water in the form of solid, liquid, and gas in Earth's lakes, rivers, oceans, polar ice, atmosphere, soil, and groundwater. Full description.

This description of a ground-water aquifer has a graphic representation to accompany it. It is part of the U.S. Geologic Survey's Water Science for Schools website. Links to other parts of the site, such as definitions and types of wells, are included. Full description.