Biomass Burning Plumes in the Vicinity of the California Coast: Airborne Characterization of Physicochemical Properties, Heating Rates, and Spatiotemporal Features. Issue 23 (5th December 2018)

• Record Type: Journal Article
• Authors: Mardi, Ali Hossein; Dadashazar, Hossein; MacDonald, Alexander B.; Braun, Rachel A.; Crosbie, Ewan; Xian, Peng; Thorsen, Tyler J.; Coggon, Matthew M.; Fenn, Marta A.; Ferrare, Richard A.; Hair, Johnathan W.; Woods, Roy K.; Jonsson, Haflidi H.; Flagan, Richard C.; Seinfeld, John H.; Sorooshian, Armin
• Is Part Of: Journal of geophysical research. Volume 123:Issue 23(2018)
• Page Start: 13, 560
• Page End: 13, 582
• Publication Date: 2018-12-05
• Subjects: biomass burning -- aerosol -- injection height -- stratocumulus clouds -- Soberanes Fire -- California; Atmospheric physics -- Periodicals; Geophysics -- Periodicals; 551.5
• DOI: 10.1029/2018JD029134
• Languages: English
• ISSNs: 2169-897X

Abstract

Abstract: This study characterizes in situ airborne properties associated with biomass burning (BB) plumes in the vicinity of the California coast. Out of 231 total aircraft soundings in July–August 2013 and 2016, 81 were impacted by BB layers. A number of vertical characteristics of BB layers are summarized in this work (altitude, location relative to cloud top height, thickness, number of vertically adjacent layers, interlayer distances) in addition to differences in vertical aerosol concentration profiles due to either surface type (e.g., land or ocean) or time of day. Significant BB layer stratification occurred, especially over ocean versus land, with the majority of layers in the free troposphere and within 100 m of the boundary layer top. Heating rate profiles demonstrated the combined effect of cloud and BB layers and their mutual interactions, with enhanced heating in BB layers with clouds present underneath. Aerosol size distribution data are summarized below and above the boundary layer, with a notable finding being enhanced concentrations of supermicrometer particles in BB conditions. A plume aging case study revealed the dominance of organics in the free troposphere, with secondary production of inorganic and organic species and coagulation as a function of distance from fire source up to 450 km. Rather than higher horizontal and vertical resolution, a new smoke injection height method was the source of improved agreement for the vertical distribution of BB aerosol in the Navy Aerosol Analysis and Prediction System model when compared to airborne data. Key Points: Significant biomass burning (BB) layer stratification with majority of layers in the free troposphere within 100 m of the boundary layer top A new smoke injection height method improved agreement for the vertical distribution of BB aerosol in the NAAPS model versus in situ data Shortwave heating rate profiles demonstrate the combined effect of stratocumulus cloud and BB layers and their mutual interactions