Twelve dust storms this spring have coated the southwestern Rockies with dust speeding snowmelt by 35 days earlier than average. The faster snowmelt will lead to decreased runoff later in the season, a climate change prediction that is being realized all too soon. The dust storm frequency was a bit unexpected however.
In the entire year of 2003, four dust storms hit the Rockies. Eight have occurred in each of the last three years, and 12 just this spring alone. The increased snowmelt is caused by the dust heating up as it soaks up the sun light energy. Snow reflects up to 90% of the sun’s energy, dust absorbs over 70% of the sun’s energy and turns it to heat.
The amount of dust in the Rockies recently has been five times greater than the pre 1900 normal. The dust bowl of the 1930’s saw dust levels seven times the pre 1900 normal. Climate prediction models show the south western U.S. seeing permanent dust bowl conditions by 2050. Like most other climate model predictions, are we beginning to see dust bowl conditions a bit ahead of schedule?
USGS http://sbsc.wr.usgs.gov/crs/news_info/dust_storms/
LA Times http://www.latimes.com/news/nationworld/nation/la-na-pink-snow24-2009may24,0,1077488.story