NASA Satellite Images Provide Clues to Understanding Fire across the Globe


NASA Satellite Images Provide Clues to Understanding Fire across the Globe

23 April 2013

published by www.scientificamerican.com


Global — For two weeks in April the world was ablaze. NASA satellites documented these infernos, both wild and controlled, as they burned from the U.S. to Australia

Wildfires can start spontaneously; vegetation can become so dry that sunlight can ignite it. Farmers also set deliberate, controlled fires, usually to clear crop residue in preparation for a new planting season. All of those fires play a role in the planet’s carbon cycle, which is why in October 2011 the newly formed NASA Fire and Smoke initiative began using NASA’s MODIS (Moderate-Resolution Imaging Spectroradiometer) to track them. The MODIS project consists of two electromagnetic measuring instruments observing Earth’s surface from the satellites Terra and Aqua, which are in polar orbits but travelling in opposite directions; together, they monitor wildfires and agricultural burns across the planet. This month was the first time ever that MODIS captured fires raging almost simultaneously around the globe.

Australia

Victoria, Australia’s most densely populated state, is dotted with national parks. These large areas of vegetation have been a source of major local concern since wildfires, or bush fires, began occurring there in the 19th century. In recent years, however, bush fires in Australia have claimed more land and lives. In 2009 the Black Saturday bush fires that raged from February to March killed 173 people and burned over 445 hectares. This natural-color satellite image, collected on April 9, 2013, captures a bush fire and its resulting plumes of smoke as they spread over the Tasman Sea. Actively burning areas, detected by MODIS’s thermal bands, are outlined in red.

NASA Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team, GSFC
 
Mexico

Mexico’s dry season, which runs from January through May, is also fire season. In 2011 more than 525,000 hectares of land burned during this time of year in the region’s largest wildfire since the 1980s. Scientists attributed the event to severe weather in 2010: One of the wettest rainy seasons on record, combined with flooding from Hurricane Alex, they say, encouraged the growth of thick grasses, which later provided ample fuel for fire. This image, taken in April 2013, shows conflagrations both deliberate and wild lighting up the region.

NASA Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team, GSFC

 United States

For the past 25 years the amount of U.S. land burned each year has risen. That trend is likely to continue: Using NASA satellite data and climate models, scientists now project that drier conditions will most likely increase fire activity across the U.S. by 2050. During the week of March 27, 2013, when this photograph was taken, more than 1,000 new wildfires spread across the southeastern U.S.

NASA Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team, GSFC

 India and Nepal

India is one of the world’s biggest producers of wheat and rice, second only to China. The majority of its population depends on agriculture for its livelihood. Many of the fires in this photograph of India and Nepal (fires appear as red dots) were set for agricultural purposes. Because of its position—both economic and physical—in the world, India is also one of the countries most susceptible to climate change. Economist William Cline found that whereas a rise of 2.5 percent in global temperatures would cut agricultural productivity in the U.S. by 6 percent, it would lead to a 38 percent reduction in India. [Less] [Link to this slide]

NASA Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team, GSFC
 
Indochina

Farmers in Burma (aka Myanmar) rely on slash-and-burn, or shifting, cultivation that involves setting fire to areas of forest to transform them into fields for crops. The smoke from shifting cultivation, as seen in this image, is extensive. Four days before this photograph was taken, a local newspaper in Laos announced flight delays due to farm-generated smoke that had originated in neighboring Burma. [Less] [Link to this slide]

NASA Jeff Schmaltz, LANCE/EOSDIS MODIS Rapid Response Team, GSFC

 


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