JUNEAU - Cold, clear weather brought air emergencies and subsequent wood stove burning bans to the Mendenhall Valley earlier this week.
Emergencies are designated when the air particulate average taken by a station near Floyd Dryden Middle School reaches or is close to an unhealthy level. The first air emergency of the year was Monday; the second began Tuesday morning.
Air emergencies and burning bans can last for a few days, said Dan Bleidorn, lands and resource specialist with the city.
"It really depends on the weather situation," Bleidorn said. "On calm, sunny, clear days the air stays stagnant at ground level. .. it's usually really the cold, clear days that have no air movement."
Bleidorn has been updating the city's Web site, www.juneau.org, three or four times a day. The Lands department also updates the automated message at 586-5333.
Pellet stoves are exempt from the wood stove regulations and can burn at any time.
Open burning is prohibited in the Mendenhall Valley and Lemon Creek area from Nov. 1 to March 31.