Results for: 2003
Weighing Earth's Water from Space
December 23, 2003Launched 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, fundamental force of nature--gravity--the satellites respond to changes in Earth's gravitation field that signal shifts in the movement of water a cross and under Earth's surface. Read more
Savanna Smog
December 8, 2003Each 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. Read more
Drought Lowers Lake Mead
November 28, 2003In 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. Read more
Denali's Fault
November 19, 2003During the afternoon of November 3, 2002, the water in Seattles 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? Alaskas Denali Fault was on the move, jostling the state with a magnitude 7.9 earthquake. Read more
Dwindling Arctic Ice
November 19, 2003Since 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. Read more
Little Islands, Big Wake
October 22, 2003The Hawaiian Islands interrupt the trade winds that blow across the Pacific Ocean, with far-reaching effects on ocean currents and atmospheric circulation. Read more
Watching the World Go By
October 22, 2003Space 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. Read more
Just Add Water: a Modern Agricultural Revolution in the Fertile Crescent
September 15, 2003Satellite 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. Read more
Land Matters
September 9, 2003Storm-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 were also at work. Read more
Double Vision
September 3, 2003For 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 modelers, and forecasters with nearly global coverage of the world's ocean surface at an unprecedented level of precision. Read more
Watching our Ozone Weather
August 22, 2003Until 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. Read more
The Incredible Glowing Algae
August 8, 2003The latest development in oceanographic remote sensing enables researchers to detect the glow, or phytoplankton fluorescence, from chlorophyll. Read more
Under a Variable Sun
August 4, 2003In 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 solar energy reaching the Earth has increased over the past two solar cycles, while other scientists doubt that any such change has occurred. This story describes how gaps in the set of observations and uncertainty about the accuracy of different satellite sensors have made splicing together a complete data set so controversial. Read more
Searching for Atlantic Rhythms?
July 14, 2003All 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 America and Europe. Read more
The Great Bend of the Nile, Day and Night
July 1, 2003Photographs from the Space Shuttle reveal the densley populated communities along the banks fo the Nile River. Read more
Squeezing Water from Rock
June 24, 2003Survivors 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 Read more
A Delicate Balance: Signs of Change in the Tropics
June 19, 2003While 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 sunlight has been reflecting off of the clouds. Read more
Global Garden Gets Greener
June 5, 2003Between 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 land-based vegetation increased by 6 percent during the time period. The greatest increase occurred in the tropics, where decreasing cloudiness made more sunlight available. Compared to the increase in human population, however, the small increase in productivity has not changed the Earth's habitability in any significant way. Read more
Lightning Spies
June 3, 2003In 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. Read more
Vanishing Ice
May 7, 2003Konrad 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. Read more
Escape from the Amazon
April 23, 2003In 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 carbon cycle need answers more than in the Amazon Rainforest. Using satellite mapping and ground-based observations, scientists have discovered that carbon dioxide gas escaping from wetlands and flooded areas is a significant source of carbon emissions in the Amazon. Read more
Measuring Ozone from Space Shuttle Columbia
April 1, 2003New 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 observed ozone change, like the ozone hole, occurs. Read more
How on Earth was this Image Made?
March 25, 2003Remotely 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 otherwise impossible view of the Earth, showing underwater mountain ranges, cloud-free skies, and city lights that are brighter than daylight. Such visualizations are invaluable for interpreting complex data and communicating scientific concepts. Read more
From Space to the Outback
March 18, 2003The 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 agencies developed a new fire monitoring system that uses observations from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on the Terra and Aqua satellites to identify fires in remote locations in Australia. The system provides a big-picture perspective of fires across the country and helps fire emergency agencies allocate resources to the areas where they are needed most. Read more
Flame & Flood
March 12, 2003In 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. Read more
The Human Footprint
February 25, 2003In 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 mandrinette hibiscus plants remain in the wild. Read more
Chemistry in the Sunlight
January 28, 2003Ozone 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 chemical reactions involved in ozone production. Read more
Solar Radiation and Climate Experiment (SORCE) Fact Sheet
January 21, 2003Earth 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 solar radiation much more accurately than anything now in use and observe some of the spectral properties of solar radiation for the first time. With data from NASA's SORCE mission, researchers should be able to follow how the Sun affects our climate now and in the future. (Original 2001-11-30; updated 2003-01-21) Read more
The Road to Recovery
January 21, 2003A recent study in the Amazon rain forest shows that some types of logging may not negatively impact the carbon cycle as originally thought. Read more
ICESat Factsheet
January 9, 2003The 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 the polar-specific coverage over the Greenland and Antarctic ice sheets. Read more
Browse Topics
World of Change
Satellite images showing how our world— forests, oceans,
cities, even the Sun— has changed in recent decades.
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Blue Marble
Composite satellite images of the entire Earth.
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Earth at Night
The night side of Earth twinkles with light in these composite global and regional views.
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Experiments
Hands-on educational activities.
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Visible Earth
A catalog of NASA images and animations of our home planet.
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NASA Earth Observations
View, download, and analyze imagery of Earth science data.
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NASA Global Climate Change
Vital signs of the planet.
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Earth Science Picture of the Day
Photos of Earth processes and phenomena.
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