The Bay Area is on a roll -- not one to brag about, however. With at least two streaks in December, one lasting 11 days, this winter looks to shatter the record for the number of Spare-the-Air days, the longstanding campaign by regional air quality regulators to curb particulate air pollution by restricting wood-burning. Twenty-two are already in the books.
That's about double the number of actual days so far with unhealthy air. So how do they know when to "pull the trigger" and ask us to "spare the air"? The process starts with meteorologists at the the Bay Area Air Quality Management District, who look daily at the weather forecast and from that, try to handicap whether the nine-county Bay Area will exceed federal air pollution standards the following day.
Art & Science
"It is a bit of an art and a bit of a science mixed together," says Kurt Malone, senior meteorologist with the Air District.
Malone and his team look partly at wind and temperatures to judge whether the Environmental Protection Agency's national standard for particulate air pollution is "likely to be exceeded" here in the Bay Area on the next day. That's a score above 100 on the EPA's AQI scale.