A series of fires that started on Jan. 7 in Palisades and Eaton burned across Southern California until heavy rains assisted firefighters in fully containing them last week.
The fires were accompanied by gusts of wind up to 90 miles per hour and intense drought conditions. And as late as Sunday, Jan. 25, almost two weeks after the first fire, new fires began in the surrounding Los Angeles area. Twenty-nine people have died, 55,000 acres have burned and more than 15,000 structures have been destroyed. Though the vast majority of fires are contained, air quality warnings continue to plague Southern California as hazardous dust and ash settles across the area.
Volker Radeloff, a fire expert and professor of Forest and Wildlife Ecology at the University Wisconsin-Madison, conducts research on wildland-urban interfaces (WUIs), which are fire-prone regions on the cusp between wildland vegetation, often woodlands or grasslands, and civilization. Nearly half of the world’s population lives in a WUI, and all of the areas that burned in the Los Angeles area belonged to a WUI, Radeloff said.
“When fire starts in the chaparral vegetation of Southern California, the winds will take pieces of burning vegetation, the bark or so, and then blow it into urban areas. We call those burning pieces fire brands or embers, and they can fly for over a mile,” Radeloff said.
Human interference can destructively alter natural fire regimes in the area, especially in densely populated areas like Southern California, leading to more frequent fires and encroachment from invasive species. Both the Palisades and Eaton fires are suspected to have manmade causes.
“The vast majority of [wildfires in California] are started by people,” Radeloff said. “That means they occur at times when fires would not occur naturally, and they occur more frequently.”
Strong evidence suggests the Eaton fire started because of an electrical fault in local transmission lines, causing an arc. The specific cause of the Palisades fire is unknown, but is thought to be man-made as well, according to the Los Angeles Times.
Climate change exacerbated the fires’ effects, according to Radeloff.
“We actually had a year of high rain last year,” Radeloff said. “What that means is that the vegetation can grow quite nicely, especially grasses and other herbaceous plants. Then they dry out, and there's a lot of fuel in the landscape. It's this combination of a wet year followed by a dry year that gives us the highest risk of the wildfires, and with climate change, we see that combination more often.”
Radeloff said wildfire events are also likely to occur in Wisconsin during periods of drought, Typically, the most deadly fires in the United States have occurred in the Midwest, and the deadliest U.S. fire on record, the Peshtigo fire, occurred in Wisconsin in the 1870s.
“It may not be quite as dramatic as what we saw [in California] because we don't have the same annual winds,” Radeloff said. “A summer of extreme drought… is what it would take for such a devastating fire. Typically in Wisconsin, the fire season is early in the spring or summer, May or so, but then the vegetation greens up differently from California, which stays dry all summer.”
UW-Madison satellite technology helps track wildfires
Government officials and citizens alike used UW-Madison satellite technology to track the wildfires. The Cooperative Institute for Meteorological Satellite Studies (CIMSS), which is a part of the Space Science and Engineering Center (SSEC) at UW-Madison, is in the process of developing what it calls a Next Generation Fire System using funding from the National Oceanic and Atmospheric Administration (NOAA).
Previous fire detection algorithms have been designed separately for geostationary satellites, which view the Earth from only one vantage point, and for satellites in polar orbit. But Brad Pierce, an Atmospheric and Oceanic Sciences faculty member and director of the Space Science and Engineering Center who has the development of the Next Generation Fire System (NGFS), said the Next Generation Fire System is “satellite agnostic,” meaning that it can be applied to sensors on both geostationary and polar-orbiting satellites.
The NGFS is currently focusing on upgrading fire detection on the Visual Infrared Imaging Radiometer Suite, a sensor developed by NASA and NOAA that can detect a variety of weather conditions, including snow, ice, clouds and smoke plumes.
The sensor is attached to two polar orbiting satellites, allowing for overpasses four times a day. The NGFS is also developing retrieval technologies for Geostationary Operational Environmental Satellites (GOES), typically the types of satellites whose imagery is shown in weather reports.
“The previous algorithms were designed for global applications, and so some of the detections and the quality control was pretty tightly constrained,” Pierce said. “The NGFS is designed for early detection so that we can get that satellite information along with all the other auxiliary information we need to the ground for the people that are managing the fires.”
Michael Pavlonis, another researcher at the SSEC, originally developed the satellite agnostic software to detect volcano eruptions. The ability of the software to detect thermal anomalies allowed for its modification into fire detection software.
The Los Angeles Fire Department did not rely heavily on satellite imagery in firefighting because the fires started in a populated area and were quickly detected by people on the ground. But geostationary satellites using technology developed at the SSEC were able to detect the fires starting in the same five-minute interval it took for people to discover them on the ground — from 23,000 miles away in space.
“One of the key things that [the NGFS] provides is an estimate of the intensity of the fire,” Pierce explained. “It's called fire radiation power. We can use that intensity to understand how much smoke and other gases are being emitted from the fire. So it's important from a fire modeling perspective, trying to picture what’s going to happen and what part of the population would be impacted by smoke from those fires.”
A prototype of the NGFS is currently available through the university, and the technology will eventually be broadly available through NOAA.
