Miguel José Serra:
The fires in California recently were brought home when my son said over the telephone that the smoke was very thick, and that he was going to spend the night in a hotel because he was being evacuated. The Otay fire was within 5 miles of his house when it was finally contained. He and I have gone up to Julian several times, not only for pies, but mostly for the "Candy Mine" in the local drugstore which has all kinds of hard-to-find candies (Sen-Sen, anyone?). It's a cute set-up at the back of the store like and old adit with several side passages full of buckets of candy. I was glad to hear that the old section of Julian was saved.
There is a nice satellite photo from the Scripps Institute Visualization Center of the smoke plumes from fires in Alta and Baja California here. Many of the agencies that fight fires have coordinated data and put it on the web for both their own use in firefighting and for public viewing through the Geospatial Multi-Agency Coordination system, GeoMAC. You can pull up fire active and historical fire perimeters on zoomable maps at this site.
Seeing yet another series of fires reminded me that this is part of a natural cycle there, and of the series of New Yorker articles that ended up as the book "Assembling California" by John McPhee. I remember reading there that because the natural vegetation in California is suited to arid environments, it tends to have extremely waxy smoke when it burns. During a fire, this smoke permeates the ground, and leaves a waxy deposit covering the soil particles within a few inches of the surface. Come the rainy season, the flow that would usually soak into the ground cannot get in because of the wax, and it simply sheets off the burnt mountainsides and into the canyons. And into the culverts. And into the houses. And away with the roads. So I am predicting that with such a bad burn season, if there are substantial rains, we will see a lot of bad flooding as well this year, especially up in the mountains.
Part of what I do at work is to help fund labs that look at tree rings. Dendrochronology can often be used to determine fire frequency. Without knowing how often fires like this occur, we can't tell if they are getting worse. It's all part of the debate concerning stopping fires in the first place -- there's fairly good evidence that the decades long campaign by Smokey the Bear to stop fires at all costs was actually counterproductive, since it left even more flammable material for the next opportunity, which was then harder to fight. There's a balance between forest growth and fire, and we simply jumped in before knowing much about the cycle.
MultiProxy Paleofire Database