After burning greater than 180 sq. miles (460 sq. kilometers) of the San Gabriel Mountains in September 2020, the Bobcat fireplace now ranks among the many largest fires on report for Los Angeles County, California. The blaze started on September 6 close to Cogswell Dam, and grew steadily over the subsequent three weeks within the midst of unusually sizzling, dry circumstances.
“Robust winds which have shifted path a number of occasions over the course of the hearth helped it unfold over such a big space,” defined Natasha Stavros, a wildfire professional with NASA’s Jet Propulsion Laboratory. “And the hearth is burning on steep terrain with restricted entry to roads, which made it difficult to comprise.”
Stavros sees the fingerprints of local weather change within the Bobcat fireplace and in California’s historic 2020 fireplace season. “4 of the 5 largest fires ever recorded in California had been burning concurrently the Bobcat fireplace,” she stated. “Local weather change contributes to megafires like these by heating fuels up, drying them out, and making them extra flammable.”
Stavros and different NASA fireplace specialists have been monitoring the blazes utilizing a set of satellite tv for pc sensors. One among them, the Operational Land Imager (OLI) on the Landsat eight satellite tv for pc, acquired a picture of the burn scar (above) on September 21, 2020, whereas the hearth was nonetheless raging in Angeles Nationwide Forest. False colour makes it simpler to differentiate the burn scar. The picture combines shortwave infrared, near-infrared, and inexperienced mild (OLI bands 7-5-2) to point out lively fires (brilliant purple), scarred land that has been consumed by the hearth (darker purple), intact vegetation (inexperienced), and cities and infrastructure (grey).
As the hearth labored its method by way of the nationwide forest, it consumed giant areas of chaparral, brush, and grass. Whereas flames have principally stayed away from populated areas, they veered into elements of the Juniper Hills and Littlerock neighborhoods close to Palmdale, resulting in greater than two dozen properties being destroyed or broken. Flames additionally threatened historic Mount Wilson Observatory for a number of days, however the web site seems to have escaped critical harm.
Whereas Landsat and different satellites consistently gather information from area that’s helpful for monitoring fires, NASA typically deploys plane for superior fireplace administration analysis. On this case, the high-flying ER-2 surveyed the Bobcat fireplace on September 17, 2020, from a top of 65,000 ft (20,000 meters), about twice as excessive as business airliners fly. The pilot of the plane took the of smoke rising from the hearth proven above. In the meantime, the Airborne Seen/Infrared Imaging Spectrometer (AVIRIS) sensor on board noticed positive particulars of the hearth’s temperature, the water content material of vegetation canopies, traits of the smoke, and burn severity.
“The ER-2 with AVIRIS was in a position to picture the Bobcat fireplace on a checkout flight for the NASA Western Variety Time Collection airborne marketing campaign,” stated Robert Inexperienced, a senior analysis scientist at NASA’s Jet Propulsion Laboratory and the AVIRIS experiment scientist. “These superior measurements are supporting improvement and testing of latest algorithms that might be used with the area devices deliberate for the subsequent decade.”
“We use airborne ‘missions of alternative’, just like the Bobcat fireplace flight, to enhance our understanding of dynamic fireplace physics and Earth processes,” added Vincent Ambrosia, the affiliate program supervisor for wildfire analysis in NASA’s Earth Utilized Sciences Program. “The company helps the difference and operationalization of distinctive sensor information derived from NASA Earth Observations, similar to AVIRIS, to enhance nationwide and worldwide catastrophe administration businesses efforts to know and mitigate wildfire results.”
In response to InciWeb, the blaze was 50 p.c contained as of September 24 because of the efforts of greater than 1,600 firefighters. Whereas cooler climate and lighter winds helped firefighters sluggish the unfold in latest days, forecasters anticipate that purple flag burning circumstances might quickly return as one other warmth wave and stronger winds return to southern California within the coming days.
NASA Earth Observatory picture by Lauren Dauphin, utilizing Landsat information from the U.S. Geological Survey. by Tim Williams (NASA Armstrong Flight Analysis Heart).