Most of Earth's deserts can be found in dry areas created by global circulation patterns. The deserts of our world are not restricted by latitude, longitude, or elevation. This site, produced by the U.S. Geological Survey, uses text and pictures to describe how atmospheric circulation patterns influence the locations of deserts on Earth and possibly on other terrestrial planets as well. Full description.

In this lab activity students will use cloud cover data from five cities (real data from NASA's TRMM instrument) to prepare a data table and graph using any available software. After downloading the data from the S'COOL homepage, they will prepare a spreadsheet and graph, and write sentences describing the dependent and independent variables and describing each cloud group. The site features text, ... Full description.

Major volcanic eruptions alter the Earth's radiative balance, as volcanic ash and gas clouds absorb terrestrial radiation and scatter a significant amount of the incoming solar radiation, an effect known as "radiative forcing" that can last from two to three years following a volcanic eruption. This results in reduced temperatures in the troposphere, and changes in atmospheric circulation patterns. ... Full description.

Volcanic eruptions are thought to be responsible for the global cooling that has been observed for a few years after a major eruption. The amount and global extent of the cooling depend on the force of the eruption and, possibly, its latitude. When large masses of gases from the eruption reach the stratosphere, they can produce a large, widespread cooling effect. As a prime example, the effects of ... Full description.

Located in Camp Springs, Maryland, the Volcanic Ash Advisory Center (VAAC) produces volcanic ash advisories and ash forecast and transport models. Real-time ash adivisories, volcano graphics and imagery, and links to related topics are available at the website. Full description.

This resource provides a network of links related to a wide variety of images, photographs, and other multimedia resources from NASA archives. The site is browsable by subject, NASA Center (Goddard, Johnson, etc.), and by keyword. It also includes links to other NASA images sites. Full description.

This site provides general information on hurricanes, including how they form, where and when conditions favorable to hurricane formation exist, how wind speeds are classified, and what conditions cause hurricanes to diminish and decay. It features text, scientific illusrations, and links to related topics in other parts of the Earth Observatory website. Full description.

This site Presents a MODIS (Moderate-resolution Imaging Spectroradiometer) image of the Gulf Stream. The image is color-coded to show the variation in temperature of the ocean water. A brief description of the Gulf Stream, its direction and speed, and a link to other related imagery are included. Full description.

Most satellite instruments look only straight down, or toward the edge of the planet. To fully understand Earth's climate, and to determine how it may be changing, we need to know the amount of sunlight that is scattered in different directions under natural conditions. The Multi-angle Imaging SpectroRadiometer (MISR) is a new type of instrument, which is designed to address this issue. It views Earth ... Full description.

This collection of activities covers such topics as the greenhouse effect, the stratospheric ozone layer, filtration of incoming electromagnetic radiation, the formation of clouds, and measurement skills. Full description.