The Ubiquity of Biomass Burning Particles in the Global Remote Troposphere. GREGORY SCHILL, Karl D. Froyd, Daniel Murphy, Christina Williamson, Agnieszka Kupc, Charles Brock, Huisheng Bian, Mian Chin, Peter Colarco, Eric Ray, Alan Hills, Rebecca Hornbrook, Eric Apel, NOAA ESRL and CIRES, University of Colorado Boulder