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In the Line of Fire

Who Are NASA's Earth Explorers?

The elementary school student questioning if El Niño occurs anywhere besides the Pacific Ocean. The researcher investigating connections between Arctic ozone depletion and global climate change. The citizen scientist interested in how changing land cover and use affects animal migration patterns. And the businessperson projecting future needs for harvest, delivery and storage of crops. All of these people are Earth Explorers -- they are all connected by their curiosity about Earth system processes. This series will introduce you to NASA Earth Explorers, young and old, with a variety of backgrounds and interests.

Sean Triplett standing in front of trees and next to a dog
From ground and sky, an all-out attack is being waged against fires across the Southwest, Colorado and Alaska. As hundreds of thousands of acres burn, firefighters cut down trees using axes and chainsaws, helicopters douse flames with water and retardants, and "smokejumpers" parachute from planes to battle blazes in remote locations.

Image to right: Sean Triplett arrives home from his two-week tour with a firefighting crew. Credit: NASA

High above these raging infernos -- 705 kilometers up, to be exact -- a NASA satellite instrument collects data to help national, state and local authorities detect developing fires, anticipate which way they might spread, and strategically dispatch equipment and resources. The Moderate Resolution Imaging Spectroradiometer, or MODIS, onboard the Terra and Aqua satellites, constantly scans Earth for these hot spots and other environmental phenomena.

In Alaska, where several active fires currently span more than 275,000 acres, Bureau of Land Management geographer Sean Triplett is the middleman linking data gathered from space with fire response managers in the field. He works with geographic information systems to integrate MODIS fire data with maps of roads, population, topography, vegetation and other parameters.

"My job is to take all the information and process it and make some sense of it, and then disseminate it out to the parties that are going to use it," Triplett said.

It didn't take long after the first MODIS instrument was launched in 1999 for its usefulness to be realized. As wildfires spread through Montana and Idaho in the fall of 2000, MODIS allowed the U.S. Forest Service to keep track of fire activity even as heavy smoke obstructed the view from reconnaissance planes. The following year, NASA joined forces with the University of Maryland and the Forest Service to develop a system that generates fire maps within a few hours, and in some cases within minutes, after a satellite overpass.

Satellite image of fires at Cave Creek in ArizonaSatellite image of fires in Alaska and the Yukon Territory
Images above: MODIS images showing fires in Arizona (left) and Alaska (right). Credit: NASA
More recently, MODIS aerosol measurements have been fused with other satellite and meteorological data to improve forecasts of air quality, which often deteriorates downwind from large fires, while MODIS images of snow cover are combined with satellite estimates of plant health to produce seasonal fire risk outlooks.

Like Triplett, Brad Quayle, a remote sensing specialist at the Forest Service's Remote Sensing Applications Center in Salt Lake City, manipulates satellite data to support management of fires and natural resources. Using data from MODIS and other sources, the RSAC provides federal authorities with maps of fire activity and burn damage.

According to Quayle, the more active the fire season the more critical satellite information becomes. The current fire season is on track to be one of the worst ever in the Southwest, where a wet spring has produced abundant grass and other combustible vegetation. As of July 1, more than 730,000 acres had burned in Nevada, more than double its previous year-to-date high, while in Arizona and New Mexico fires had scorched more than 400,000 acres, almost 100,000 more than the average year-to-date total.

"When you have all these large fires burning in several states at once, the importance of the MODIS fire detection products is magnified," Quayle said. "Because sometimes there's not enough resources around to keep track of all these fires."

While MODIS is used for fire response throughout the United States and other countries, it is especially important in Alaska, where fires often occur in remote areas not accessible by road, and resources such as aircraft are more limited than in the lower 48. Another benefit unique to Alaska is that MODIS can help locate open bodies of water -- it's not uncommon for fires to occur when many lakes are frozen over -- where water-bombing planes can refill.

"Satellites are a huge source of intelligence here," Triplett said. "Satellites are another eye in the sky."

Recently, Triplett had a chance to see firsthand why his work is so important. He went out for two weeks with a crew battling the Sheenjek River fire, which as of July 1 had burned more than 82,000 acres near Fort Yukon, Alaska. Triplett was right on the frontlines -- running water pumps, clearing brush, attacking the fire just like any other member of the crew -- so he could "get a perspective of life on the ground and therefore produce better GIS products for fire line personnel."

Back at the office in front of his computer, after 14 days of feeling intense heat, inhaling toxic smoke, living without running water and surviving on MREs (meals ready to eat), Triplett had just one complaint:

"I still can't get any of my clothes to get all the smoke smell out of it."

See previous Earth Explorers articles:
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Related Resources
MODIS Active Fire Mapping Program
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MODIS Rapid Response System
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Event-Based Science: Fire!
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Dan Stillman, Institute for Global Environmental Strategies