Launched in 2002, a pair of identical satellites that make up NASA's Gravity Recovery And Climate Experiment (GRACE) are tackling the problem in an unexpected way: they are weighing Earth's fresh water from space. Serving as a sort of "divining rod" in space that moves in response to a powerful,…

Each August in southern Africa, literally thousands of people equipped with lighters or torches go out into the African savanna, a region dotted with villages and teaming with animals, and intentionally set the dry grasslands ablaze.

In the space of just three years, water levels in Lake Mead have fallen more than sixty feet due to sustained drought. Landsat images show the extent of the change to the lake's shoreline.

Since the 1970s, Arctic sea ice has been melting at the rate of 9 percent per decade. NASA researcher Josefino Comiso points to an accelerating warming trend as a primary cause and discusses how global climate change may be influencing the shrinking Arctic ice cap.

During the afternoon of November 3, 2002, the water in Seattle’s Lake Union suddenly began sloshing hard enough to knock houseboats off their moorings. Water in pools, ponds, and bayous as far away as Texas and Louisiana splashed for nearly half an hour. The cause? Alaska’s Denali Fault…

The Hawaiian Islands interrupt the trade winds that blow across the Pacific Ocean, with far-reaching effects on ocean currents and atmospheric circulation.

Space Station Science Officer Ed Lu describes what it is like to look at the Earth over the course of an orbit. His descriptions are accompanied by digital photographs of Earth he has taken and transmitted to the ground during his mission.

Satellite observations in the Middle East's Fertile Crescent have documented a modern agricultural revolution. The dramatic changes in crop production in southern Turkey over the last decade are the result of new irrigation schemes that tap the historic Tigris and Euphrates Rivers.

Storm-related losses from the 1982-83 El Nino cost the state of California an estimated $2.2 billion. Fifteen years later, damages from the 1997-98 El Nino cost California only half that amount. Differences in storm intensity and duration accounted for some of the reduced costs, but other factors…

For the first time, scientists can rely on not one, but two satellites to monitor ocean surface topography, or sea level. TOPEX/Poseidon and Jason-1, launched nearly 10 years apart, are now engaged in a tandem mission, creating a spaceborne ocean observatory that provides scientists, climate…

Until about 30 years ago, atmospheric scientists believed that all of the ozone in the lower atmosphere (troposphere) intruded from the upper atmosphere (stratosphere), where it formed by the action of sunlight on oxygen molecules.

The latest development in oceanographic remote sensing enables researchers to detect the glow, or phytoplankton fluorescence, from chlorophyll.

In their continued effort to understand the Sun, solar physicists of the 21st century have used satellite data to study how much energy reaches the outskirts of the Earth’s atmosphere and whether or how much that amount varies over time. Recently published research claims that the amount of…

All over the globe there are relationships between the conditions of the atmosphere and oceans that affect weather and climate at great distances. The North Atlantic Oscillation is one of these teleconnections, linking the temperature of the North Atlantic Ocean with winter weather in North…

Photographs from the Space Shuttle reveal the densley populated communities along the banks fo the Nile River.

Survivors of the New Madrid earthquakes reported not only intense ground shaking and land movement, as would be expected during an earthquake, but also an unfamiliar phenomenon: water and sand spouting up through fissures, or cracks, in the Earth's surface

While NASA climate scientists were reviewing radiation data emanating from the tropics simply to test existing notions, they uncovered a phenomenon no one expected. They found that progressively more thermal radiation has been escaping the atmosphere above the tropics and progressively less…

Between 1982-1999, the climate grew warmer, wetter, and sunnier in many parts of the global greenhouse. For the most part, these changes were favorable for Earth's vegetation. Satellite observations of vegetation combined with nearly 20 years of climate data reveal that productivity of Earth's…

In 1997, NASA launched the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. The LIS detects and maps the distribution and variability of cloud-to-cloud, intracloud, and cloud-to-ground lightning.

Konrad Steffen arrived on the Greenland Ice Sheet for the 2002 fieldwork season and immediately observed that something significant was happening in the Arctic. Pools of water already spotted the ice sur face, and melting was occurring where it never had before.

In this era of heightened concern about the relationship between the build up of atmospheric carbon dioxide and climate change, scientists are working to itemize all the ways carbon moves into and out of forest ecosystems. Perhaps nowhere on Earth do questions about the role of forests in the…

New remote-sensing technology called limb viewing allows observation of the atmosphere from the side rather than straight down. From that side view the layers of the atmosphere appear like layers in a cake, allowing instruments to see the lower layers of the stratosphere where most of the recently…

Remotely sensed Earth observations can include everything from sonar measurements used to map the topography of the ocean floor to satellite-based observations of city lights. Combining observations collected by a variety of instruments at different times and places allow scientists to create an…

The 2002-03 fire season in Australia echoes the devastating 2001-02 season that climaxed in the bush on the outskirts of Sydney and drew international attention once again to the city that had hosted the 2000 Summer Olympics. In the aftermath of that season, Australian scientists and government…

In the desert, fires can move fast; constant winds funnel through shallow dry creek beds to keep parched vegetation burning. A hot fire can make soil "hydrophobic," meaning that water runs off instead of soaking into the ground.

In North America, the black-tailed prairie dog occupies as little as 5 percent of its former habitat. In Madagascar, more than 20 lemur species are threatened with extinction, and at least 15 species are already extinct. And on the island of Mauritius in the Indian Ocean, fewer than 50 mature…

Ozone has proven to be among the most difficult air pollutants to control. To control ozone requires understanding its complex chemistry and how the chemical travels from one locality to another. Chemistry in the Sunlight explains basic aspects of ozone formation and provides a sample set of…

A recent study in the Amazon rain forest shows that some types of logging may not negatively impact the carbon cycle as originally thought.

Earth scientists will move a step closer to a full understanding of the Sun's energy output with the launch of the Solar Radiation and Climate Experiment (SORCE) satellite. SORCE will be equipped with four instruments now being built at the University of Colorado that will measure variations in…

The ICESat mission will provide multi-year elevation data needed to determine ice sheet mass balance as well as cloud property information, especially for stratospheric clouds common over polar areas. It will also provide topography and vegetation data around the globe, in addition to…