California Today: Here’s What’s Been Different About Fires This Year
By Thomas Fuller and Matt Stevens
Good morning.
(Want to get California Today by email? Here’s the sign-up.)
The huge wildfires across California in recent weeks have underlined what fire experts describe as the new normal for the state. But firefighters say it’s more than just the scale and the timing of the fires that is different.
Chris Anthony, a division chief at the California Department of Forestry and Fire Protection, says fire behavior appears to be changing on a more micro level. One example: In mountainous terrain, fires typically run much faster uphill as the fire heats the fuels above it, making them more readily combustible.
But Mr. Anthony says his firefighters are seeing more examples of fires running fast downhill, too.
Another example: Firefighters for decades were accustomed to seeing fires slow down considerably at night, said Scott L. Stephens, a professor of fire science at the University of California, Berkeley. But a number of recent fires have continued to advance rapidly through the night.
“Many times now in the evening fires are burning at night almost as active as they are in the day,” Professor Stephens said. “Things are happening here in California that 10 years ago I never heard about.”
ADVERTISEMENT
Craig Clements, a meteorologist at San Jose State University who specializes in the behavior of wildfires, says experts are still trying to quantify and confirm changes in fire behavior.
It’s certain that California is seeing much larger fires, he said, and much of that is connected to drier conditions. One of his students has investigated what are known as nocturnal drying events — when very dry air coming off the Pacific Ocean leaves higher altitudes desiccated.
“It’s most cool and foggy down in the Bay,” he said of the San Francisco Bay. “You have a sea breeze coming in. But above the sea breeze some of the driest air in North America is coming in. Up in the hills it’s super dry.”
Changes in fire behavior have consequences both for firefighters and for people who live near open spaces, said Mr. Anthony, the Cal Fire division chief.
“What we thought was normal or average isn’t normal anymore,” he said. “We have to change our thinking.”
No comments:
Post a Comment