The ocean and atmosphere each react to changes in the other. These reactions and counter-reactions can snowball until the system builds to a point where potentially disastrous effects occur, such as the El Nino events of 1982-83 and 1997-98. This site describes how the Jet Propulsion Laboratory's TOPEX-Poseidon satellite was used to monitor the amount of sea level rise in the Eastern Pacific Ocean, and consequently the amount of heat stored in the water. Sea level and temperature data from TOPEX-Poseidon was used successfully to predict the 1997-98 El Nino event earlier than ever before. It features text, remotely-sensed imagery and a link to JPL's Physical Oceanography website.

Forest fires, brush fires, and slash and burn agriculture are a significant force for environmental change. Remote sensing of fires, smoke and burn scars allows for improved detection of fire characteristics as well as their short- and long-term effects on ecosystems. This site from NASA's Earth Observatory discusses the importance of fires, trace gases emissions, aerosol emissions, and NASA and NOAA missions for monitoring global fires. Case studies and data sets are also available.

This article provides a brief discussion of the issues surrounding global warming. Topics include greenhouse gas emissions, the possible consequences of global warming, and debates among proponents and opponents about whether global warming is indeed happening and whether it represents a danger to the planet.

This image-rich National Aeronautics and Space Administration Earth Observatory article discusses how Ken Carder and his research team are using remote sensing data and offshore monitoring to find and track harmful algal blooms as they form and spread. Methods of correlating satellite data with field data and modeling are allowing scientists to determine the causes and precursors of harmful algal blooms. With that knowledge comes the possibility of detecting the start of a bloom, alerting coastal communities earlier, and mitigating some of the red tide's toxic effects, such as fish kills and shellfish poisoning. The article contains a glossary, that may be clicked on and off, and links to related websites.

This website, provided by NASA's Earth Observatory, describes the science behind hurricanes. Sections include hurricane formation and decay, hurricane anatomy, information regarding storm surges, hurricane climatology, a description of the Saffir-Simpson scale and NASA study missions. Users will also find a list of references regarding hurricanes and hurricane science.

This NASA site hosts a composite image of the southern lights Aurora over the South Pole. A link enables visitors to view a video of this aurora. The image of the Aurora is overlaid on a NASA ‰ÛÏBlue Marble‰Û� image also captured by satellite. Text describes the distortion of Earth‰Ûªs magnetic field by the stream of protons and electrons from the sun.

As NASA's Earth Observatory Web site describes: "Each year, the North Atlantic Ocean announces springtime by producing 'blooms' large enough to be seen from space." While scientists have had satellite images of these phytoplankton blooms for years, researchers can now detect biofluorescence from these microscopic organisms, with important implications for monitoring the environment. The Web site presents some of these incredible images, along with an interesting essay on the topic (which includes a handy hypertext glossary).

The latest releases from the National Aeronautics and Space Administration's (NASA's) Earth Observatory include an eight-day composite map illustration showing the maximum snow cover in North America during the period March 5-12, 2000. The data were obtained using MODIS, a sensor aboard the Terra spacecraft. "When compared to the snow extent during average years, it is apparent that there was significantly less area covered by snow this year for each month from November through April."

The purpose of NASA's Earth Observatory is to provide a freely accessible publication on the Internet where the public can obtain new satellite imagery and scientific information about our home planet. The focus is on Earth's climate and environmental change. The site is divided into six main sections: Data and Images, Features, News, Reference, Missions, and Experiments. The Data and Images, Features, and Reference sections are each subdivided into sections for Atmosphere, Oceans, Land, Life on Earth, and Heat and Energy. The missions section explains all of the current NASA missions, and the Experiments section contains activities related to the topics covered in the other sections. Information provided in these pages includes text, photographs, animations, maps, and datasets. The site also includes a glossary, "ask a scientist" feature, and links to current news stories.

As part of NASA's Earth Observatory, visitors to the Escape from the Amazon Web site are invited to "Accompany NASA scientists as they explore our world and unravel the mysteries of climate and environmental change." The Escape from the Amazon feature focuses on the buildup of carbon dioxide and its effect on global climate change, and the role that forests play in reversing this trend. A really neat feature of this site is a glossary function that can be turned on or off. When on, it highlights technical terms. Clicking on any highlighted term will bring up a very descriptive and straightforward definition. Also included as the second part of the feature is an introduction to the large-scale Biosphere-Atmosphere Experiment in Amazonia. This feature highlights the enormity and significance of the Amazon River Valley and its effect on global climate. This Web site is a great outreach and educational tool offered by NASA and should be interesting to lay readers, scientists, and teachers. Several great graphics help to illustrate the information provided.

NASA's Earth Observatory is a "freely-accessible publication on the Internet where the public can obtain new satellite imagery and scientific information about our home planet." The Earth Observatory feature presented in this Web site introduces documented changes in plant productivity over the last two decades -- the warmest decades on record. The study, based on satellite imagery and ground observations, also demonstrates the most important of those factors influencing changes in plant productivity. Readers will find an informative overview of the study and terrific high-resolution images.

This fun, interactive website was designed by NASA's earth observatory to introduce students to the Earth's Biomes. A biome, as defined by the site, is "a community of plants and animals living together in a certain kind of climate." This website provides links to seven different biomes that students can learn about including coniferous forests, grasslands, and tundras. Each separate biome page contains a brief general description as well as basic information about characteristics such as Temperature, Vegetation, and Location. The biome pages also link to a Vocabulary page, a handy Metric Converter, and a Teacher Resource section that includes Goals, Outcomes, National Standards, and Extension Ideas. This website also offers interactive biome graphing and planting activities.

This page, from National Aeronautics and Space Administration's Earth Observatory, contains a satellite image of the mouth of the Mississippi River and the nearby Gulf of Mexico. The sediment carried by the river following a rainstorm is clearly evident as it mixes with the dark blue water. The site also contains links to the Newsroom and other recent images.

The purpose of NASA's Earth Observatory is to provide a freely-accessible publication on the Internet where the public can obtain new satellite imagery and scientific information about our home planet. The specific focus of this Earth Observatory website is natural hazards. Earth scientists around the world use NASA satellite imagery to better understand the causes and effects of natural hazards. The goal in sharing these images is to help people visualize where and when natural hazards occur, and to help mitigate their effects. Natural hazards that are emphasized include dust and smoke, wildfires, floods, severe storms, and volcanoes. In addition, each week the site highlights major natural hazard events occurring around the globe. Links to satellite imagery and informational text concerning the natural hazard and image interpretation are included. The site also offers a link to unique imagery, such as earthquakes, droughts, and landslides, and features the latest unique imagery events around the globe.

This website offers NASA's Earth Observatory newest feature -- an educational module about global warming. Beginning with a recap of the tremendous heat wave that struck Europe in the summer of 2003, the website proceeds with an educational discussion about the interaction between water vapor and other greenhouse gases and the atmosphere. Users can learn about climatic modeling and some assumptions that are incorporated into these models. Students can find out how NASA scientists utilize satellite and other data to validate their climate models. The website also features a lengthy discussion about humidity and its affects on weather.

This webpage, one of NASA's fact sheets, describes the role of the oceans, clouds, and aerosols in moderating climate, which has resulted in less-than-expected temperature increases as carbon dioxide levels have increased. It also describes the efforts of scientists to construct computer models to understand interactions between the atmosphere and ocean, and to perform space-based oceanography using the Earth Observing System (EOS). The site features text, pictures, and links to other relevant NASA sites.

This webpage, one of NASA's fact sheets, describes the role of the oceans, clouds, and aerosols in moderating climate, which has resulted in less-than-expected temperature increases as carbon dioxide levels have increased. It also describes the efforts of scientists to construct computer models to understand interactions between the atmosphere and ocean, and to perform space-based oceanography using the Earth Observing System (EOS). The site features text, pictures, and links to other relevant NASA sites.

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, and links to other relevant topics, data sets, and satellite missions.

This page is part of NASA's Earth Observatory website. It features text and a scientific illustration to describe how the ocean interacts with the atmosphere, physically exchanging heat, water, and momentum. It also includes links to related data sets, other ocean fact sheets, and relevant satellite missions.

Milutin Milankovitch formulated a comprehensive mathematical model that calculated latitudinal differences in solar radiation upon the Earth's surface and the corresponding surface temperatures for 600,000 years prior to the year 1800. Readers can learn how Milankovitch developed his theories and how they were confirmed years later by climatic data found in deep-sea sediment cores, which indicated that major variations in climate such as ice ages were closely associated with changes in the geometry of Earth's orbit. This is part of NASA's Earth Observatory series of publications entitled "On the Shoulders of Giants," which are about scientists who revolutionized our understanding of the atmosphere, oceans, climate, and environment.