the ground over here, charcoal working its way up the inside of a tree trunk over there, and just over there an unburned shrub dried and heated enough to suddenly transition into combustion.
In some settings, fires smolder for days, eating through the duff that lies on the ground. In other settings, fires can smolder for years. For the purposes of mop-up, chaparral is forgiving in comparison to, for example, stands of spruce and pine. Mop-up is easier in chaparral because the fire takes most of the fuel and leaves behind exposed mineral soil, but that is not to say that it is easy. Crews are tired. Smoke and ash fill the air and saturate clothes and skin and hair. The heat of the ground finds its way through boots.
The crews search for smoke. They scan the ground with infrared scopes, looking for hot spots. When they find something smoldering, they attack with water or hand tools. In places, they work through the goop of fire suppressants dropped from airplanes and helicopters.
The Jesusita Fire burned in part over regrowth that had sprung up after the Painted Cave Fire, which had burned twenty years before. The Jesusita Fire was contained in part by the more or less barren ground left by the Gap Fire, which had burned eighteen months before. Older firefighters on the Jesusita Fire told younger firefighters about fighting the Painted Cave Fire, and younger firefighters told rookies about fighting the Gap Fire. The firefighters could, without leaving the greater urban area of Santa Barbara, also spin tales about the Refugio Fire, the Polo Fire, the Coyote Fire, the Romero Canyon Fire, the Sycamore Canyon Fire, and the Eagle Fire. Cumulatively these fires burned an area twelve times the size of Manhattan.
From our vantage points along the road, the mapper points out a wide swath of charcoaled hillsides. Through binoculars, the blackened skeletons of trees stand above a ridgeline with exposed tan bedrock and scattered boulders. I cannot tell where one fire started and another ended. The mapper finds a subtle change in color, from one shade of green to another, barely perceptible to my eyes, and says that it marks a fire line from an earlier fire.
He points to a stand of dead trees with their branches and twigs intact. “Sometimes fire will pass an area without burning it,” he tells me, “but the trees are killed by the heat or by the ash.”
Today there is no fire. Smoke does not obscure the view. Three paragliders hang in the air above us, and bicyclists pedal along the ridge road.
We scurry down a hillside of loose, sandy gravel. The smell of ash prevails.
In his work with aerial images of burned and unburned hillsides, the mapper looks at more than just color, and he maps more than just plant communities. “Water has a particular spectrum and signature,” he says.
Moisture content goes into his computer models. He starts simply, looking at fuel and slope and moisture. From there, he adds wind. He tosses in subtle changes in fuel loading that let his virtual fire move in sudden leaps interspersed with stalls. This patch of ground might be beetle killed, that patch might have a stream running through it, another patch might have burned within the past few years and have little to offer in the way of fuel.
In computer models of wildland fires, a pixel changes from green to red, indicating ignition. That pixel ignites neighboring pixels. The fire spreads. Before long, the fire creates its own weather. The fire’s own heat dries out moist vegetation. The fire’s own winds roar up gullies. The fire reaches the crest of a hill, with an updraft on one side and a downdraft on the other. The fire leaps across three green pixels, leaving them untouched, to turn four more green pixels red.
The challenge is to come up with models coupling the reasonably static reality of the landscape with the overwhelmingly dynamic reality of an uncontrolled wildfire. The challenge is to create a model that captures land burning with a
In some settings, fires smolder for days, eating through the duff that lies on the ground. In other settings, fires can smolder for years. For the purposes of mop-up, chaparral is forgiving in comparison to, for example, stands of spruce and pine. Mop-up is easier in chaparral because the fire takes most of the fuel and leaves behind exposed mineral soil, but that is not to say that it is easy. Crews are tired. Smoke and ash fill the air and saturate clothes and skin and hair. The heat of the ground finds its way through boots.
The crews search for smoke. They scan the ground with infrared scopes, looking for hot spots. When they find something smoldering, they attack with water or hand tools. In places, they work through the goop of fire suppressants dropped from airplanes and helicopters.
The Jesusita Fire burned in part over regrowth that had sprung up after the Painted Cave Fire, which had burned twenty years before. The Jesusita Fire was contained in part by the more or less barren ground left by the Gap Fire, which had burned eighteen months before. Older firefighters on the Jesusita Fire told younger firefighters about fighting the Painted Cave Fire, and younger firefighters told rookies about fighting the Gap Fire. The firefighters could, without leaving the greater urban area of Santa Barbara, also spin tales about the Refugio Fire, the Polo Fire, the Coyote Fire, the Romero Canyon Fire, the Sycamore Canyon Fire, and the Eagle Fire. Cumulatively these fires burned an area twelve times the size of Manhattan.
From our vantage points along the road, the mapper points out a wide swath of charcoaled hillsides. Through binoculars, the blackened skeletons of trees stand above a ridgeline with exposed tan bedrock and scattered boulders. I cannot tell where one fire started and another ended. The mapper finds a subtle change in color, from one shade of green to another, barely perceptible to my eyes, and says that it marks a fire line from an earlier fire.
He points to a stand of dead trees with their branches and twigs intact. “Sometimes fire will pass an area without burning it,” he tells me, “but the trees are killed by the heat or by the ash.”
Today there is no fire. Smoke does not obscure the view. Three paragliders hang in the air above us, and bicyclists pedal along the ridge road.
We scurry down a hillside of loose, sandy gravel. The smell of ash prevails.
In his work with aerial images of burned and unburned hillsides, the mapper looks at more than just color, and he maps more than just plant communities. “Water has a particular spectrum and signature,” he says.
Moisture content goes into his computer models. He starts simply, looking at fuel and slope and moisture. From there, he adds wind. He tosses in subtle changes in fuel loading that let his virtual fire move in sudden leaps interspersed with stalls. This patch of ground might be beetle killed, that patch might have a stream running through it, another patch might have burned within the past few years and have little to offer in the way of fuel.
In computer models of wildland fires, a pixel changes from green to red, indicating ignition. That pixel ignites neighboring pixels. The fire spreads. Before long, the fire creates its own weather. The fire’s own heat dries out moist vegetation. The fire’s own winds roar up gullies. The fire reaches the crest of a hill, with an updraft on one side and a downdraft on the other. The fire leaps across three green pixels, leaving them untouched, to turn four more green pixels red.
The challenge is to come up with models coupling the reasonably static reality of the landscape with the overwhelmingly dynamic reality of an uncontrolled wildfire. The challenge is to create a model that captures land burning with a
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