At Goddard, NASA scientists turn their gaze Earthward

GREENBELT NASA scientist George J. Huffman sometimes watches in awe as bands of greens and yellows and reds float across a map of the world on a 20-foot screen at Goddard Space Flight Center.

The technology he helped develop uses satellites to track rain, hurricanes and blizzards — information that allows people on the West Coast to gauge their water supply from the Sierra Nevada snowpack, students to track zebra migrations in Africa and researchers to monitor the threat of Japanese encephalitis in Australia.


Like many of the 9,000 people who work for the space agency at Goddard in Greenbelt, Huffman is charged with developing technology to study the Earth from above.

The more advances they make, Huffman said, the better people will be able to understand weather patterns and climate change in the decades to come.


"The mission is to step into the future and say, 'What is it we could do, particularly from a spaceborne perspective?'" said Huffman, of Bowie. "How can we use space assets and the viewpoint to learn more about this place where we live and make life better and increase our understanding of what is and what will be?"

Huffman, who earned a doctorate in meteorology from the Massachusetts Institute of Technology, helps lead Goddard's work using satellites, microwave data and advanced algorithms to track precipitation across the globe.

He's worked at Goddard for nearly 30 years, as a contractor and as an employee. Two-thirds of the workers at Goddard are contractors.

NASA bills the facility as the nation's largest organization to use scientists and engineers to build "spacecraft, instruments and new technology to study Earth, the sun, our solar system and the universe."


Of all the worlds NASA studies, a Goddard spokeswoman said, Earth is the most important.

"It's really about understanding our planet," Rani C. Gran said. "Our planet is really beautiful. How does it work? That's what our scientists find out."

Huffman, who was born in Iowa and grew up in Ohio, said he's been fascinated since childhood with the "amazing complexity" of tornadoes, hurricanes, typhoons, thunderstorms, blizzards and rainbows.

"It's like the baseball player who says he was overjoyed to find out that he could get paid to do this," Huffman said.

He came to the area to teach meteorology at the University of Maryland, and is now deputy project scientist for an international satellite mission that observes rain and snow throughout the world.

He also leads another project that combines data from about 10 satellites and merges them into a single map.

The work of Huffman and others gives emergency managers and crop forecasters information to monitor water levels — whether there will be enough in California, which is suffering a four-year drought, or too much in India, where monsoons can cause landslides and flooding.

The information they produce is available online for the taking and explained during NASA workshops for various groups.

"It helps a lot of different non-governmental groups," Goddard scientist Dalia Kirschbaum said. "We talk to everyone. One of the goals is to provide the real-time as well as research versions to scientists and the public."

Huffman said studying precipitation from space gives a broader picture than could be created from the ground alone.

From the Earth, radar provides snapshots of weather systems in certain areas, but has limitations: it can't see storms as they move off the coast and out into the ocean.

There's also a lack of coverage over developing countries or those with civil strife, Huffman said.

The satellites that create the images see microwave energy released by the Earth's surface and atmosphere. The snow — the latest form of precipitation added to the global project — is shown in blues on NASA's map. Rain is depicted in warm colors, such as red.

"We don't measure precipitation by satellite," Huffman explained."What we measure is the radiant energy coming up from the Earth and the atmosphere and things in the atmosphere."

Huffman said NASA uses satellites in low orbit, about 250 to 500 miles from the Earth's surface, from U.S. agencies, including the National Oceanic and Atmospheric Administration and the Department of Defense, and from Japan and Europe.

Each satellite sees a given point on Earth about two times a day. Huffman said NASA merges the images from various satellites and combines the data into a seamless map.

"What these data allow us to do is look through the clouds," Huffman said. "This is the not the first time we've been able to do this, but it's the best, so far."

The team produces several versions of the global precipitation map, including a highly refined version that shows data from three months ago and one from 16 hours ago. Scientists are working to release a 6-hour version in the coming weeks and eventually a 4-hour one, Huffman said.

The project will give scientists a better sense of the water-to-energy cycle across the globe, Huffman said. Those patterns lay a foundation for understanding long-term climate change, he said.

"That's what California is worried about," he said. "It's not a degree increase in temperature. If they don't have rain for the next three years, they're in deep, deep trouble."


Learning about Earth from space

NASA's Goddard Space Flight Center in Greenbelt employs engineers and scientists to further understanding of Earth from space. Here's a look at some of their advances:

•Measured the depletion of groundwater storage around the world by calculating how much water has been lost in natural aquifers.

•Published the first satellite images of the Antarctic ozone hole, among other efforts to help further the world's understanding of the stratospheric ozone layer. Goddard provides daily updates on the condition of the ozone layer and projects levels in the future.

•Using various satellites, NASA scientists track changes in the growing seasons with three-dimensional surveys of forest height from space. The information is essential to understanding how much carbon the forest can absorb from the atmosphere.

•Monitoring the Earth's cryosphere — the planet's frozen areas, such as the Arctic sea ice, land ice on Antarctica and Greenland, and mountain glaciers. Tracking those measurements helps chart climate change.

Source: Goddard Space Flight Center

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