[1] Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA
[2] Univ Wyoming, Dept Atmospher Sci, Laramie, WY 82071 USA
[3] Natl Ctr Atmospher Res, Res Applicat Lab, POB 3000, Boulder, CO 80307 USA
[4] Univ Illinois, Dept Atmospher Sci, Urbana, IL USA
[5] Idaho Power Co, Boise, ID USA