[1] US Forest Serv, Missoula Fire Sci Lab, Rocky Mt Res Stn, Missoula, MT 59804 USA
[2] CEA UVSQ CNRS UMR 8212, Inst Pierre & Simon Laplace, LSCE, F-91191 Gif Sur Yvette, France
[3] Norwegian Inst Air Res NILU, Dept Atmospher & Climate Res ATMOS, Kjeller, Norway
[4] US Forest Serv, Int Program, Washington, DC 20250 USA