In this lesson, students observe a teacher-directed demonstration that provides a conceptual understanding of latent heat, the "hidden heat" present in all changes from one phase to another, by using a hand warmer. Full description.

This El Nino site explains the abnormal warming of surface ocean waters in the eastern tropical Pacific and how it affects global weather, ocean circulation, and coral reef ecosystems. The activities involve wind direction and the Coriolis effect, global wind patterns, and cloud formation. There are sections comparing normal conditions to El Nino conditions and a video clip of the 1982-1983 El Nino ... Full description.

This site provides an overview of the earth's atmospheric greenhouse effect by briefly exploring the atmospheres of nearby planets and discussing the greenhouse gases of our atmosphere. Information at this site helps students to understand that the greenhouse effect is what makes this planet suitable for life as we know it and that the earth's atmosphere contains trace gases, water vapor, carbon dioxide, ... Full description.

This information is designed to belie the misconception that the capacity of air to hold water vapor is temperature dependent and that air can become saturated with water vapor. The temperature of a cloud droplet or ice crystal will be nearly the same as that of the air, so people imagine that somehow the air was to blame. But, if the other gases of the air were removed, leaving everything else the ... Full description.

The Gulf of Maine Aquarium hosts this two-part activity. The focus is on seasonal changes in the mass balance of the Antarctic Ice Sheet. Part 1 uses an atlas and satellite imagery to examine the geography of the region and the changing boundaries of the ice sheet. Part 2 tracks annual changes in sea ice. There is an animation page showing changes in ice cover around Antarctica during 1991, and links ... Full description.

Interpreting Infrared (IR) Imagery explains how radiometers are used in satellite meteorology including such topics as the types of radiometers, and how they capture and present images. An interactive exercise provides an introduction to interpreting satellite weather images typically seen on evening news programs. Users can "adjust" the air temperature (and cloud altitude) and surface temperature ... Full description.

This applet explores how the thickness of a cloud changes the way it looks from a satellite. The image is in the visible part of the spectrum, and the radiant energy is a function of not just temperature, as in the case of infrared images. The cloud thickness, its effective brightness, and the surface temperature can be modified while observing the satellite image. Full description.

This applet explores how the thickness of a cloud changes the way it looks from a satellite, as well as how modifying the surface characteristics (ground cover type) alters the brightness of the scene. Students may alter cloud thickness and vary the ground cover to include snow/ice, forests, oceans and crops. Full description.

In this demonstration, an overhead projector, diffraction grating, and a series of filters are used to introduce the basic concepts of the visible electromagnetic spectrum and the relationship between wavelength and absorption of light. The overhead projector is used to project the spectrum from the diffraction grating on the board or wall. A series of colored filters are used to filter the light ... Full description.

This applet provides a simulation of the type of precipitation that results from adjusting the temperature (dry bulb and wet bulb) at different altitudes. An updraft in the cloud can be produced in order to see its influence on precipitation. The precipitation types that are simulated include snowflakes/ice crystals, supercooled droplets, raindrops, drizzle, sleet, snow grains, and freezing rain or ... Full description.