Abood , Paul 1 ; Williams , Mark 2 ; Tonnessen , Kathy 3 ; Morris , Kristi 4 1 University of ÃÛÌÇÖ±²¥, Boulder 2 University of ÃÛÌÇÖ±²¥, Boulder 3 Rocky Mountains CESU, National Park Service 4 Air Resources Division, National Park Service NADP/NTN data are used to characterize the...