A34F-04
An overview of reactive chlorine measurements during the WINTER C-130 aircraft campaign
Wednesday, 16 December 2015: 16:45
3010 (Moscone West)
Joel A Thornton1, Felipe Lopez-Hilfiker2, Ben H. Lee2, Lyatt Jaegle3, Jessica Haskins4, Viral Shah2, Steven S Brown5, Dorothy L Fibiger6, Erin E. McDuffie7, Patrick R Veres5, Jack E Dibb8, Tamara Sparks9, Carlena J Ebben9, Ronald C Cohen9, Amy Sullivan10, Hongyu Guo11, Rodney J Weber11, Jason Clay Schroder12, Pedro Campuzano-Jost13, Douglas A Day14, Jose L Jimenez15, Teresa Lynn Campos16, Andrew John Weinheimer16, Eric C Apel17 and Nicola J Blake18, (1)Univ Washington - Seattle, Seattle, WA, United States, (2)University of Washington Seattle Campus, Seattle, WA, United States, (3)Univ Washington, Seattle, WA, United States, (4)University of Washington Seattle Campus, Atmospheric Sciences, Seattle, WA, United States, (5)NOAA Boulder, Boulder, CO, United States, (6)National Science Foundation, Atmospheric and Geospace Sciences Postdoctoral Fellow, Arlington, VA, United States, (7)University of Colorado at Boulder, Boulder, CO, United States, (8)University of New Hampshire Main Campus, Durham, NH, United States, (9)University of California Berkeley, Berkeley, CA, United States, (10)Colorado State University, Fort Collins, CO, United States, (11)Georgia Institute of Technology Main Campus, Earth and Atmospheric Sciences, Atlanta, GA, United States, (12)Cooperative Institute for Research in Environmental Sciences, Boulder, CO, United States, (13)University of Colorado at Boulder, Department of Chemistry and Biochemistry, Boulder, CO, United States, (14)CIRES, Boulder, CO, United States, (15)University of Colorado at Boulder, Dept. of Chemistry and Biochemistry, Boulder, CO, United States, (16)National Center for Atmospheric Research, Boulder, CO, United States, (17)University Corporation for Atmospheric Research, Boulder, CO, United States, (18)University of California Irvine, Irvine, CA, United States
Abstract:
As part of the Wintertime Investigation of Transport, Emissions, and Reactivity (WINTER) campaign, the University of Washington Iodide-adduct high resolution time of flight chemical ionization mass spectrometer (HRToF-CIMS) was deployed aboard the NSF/NCAR C-130 aircraft. Calibrated measurements of ClNO2, Cl2, HCl, N2O5, HNO3, HONO, among several other compounds, were made at 2Hz on all 13 research flights. ClNO2 and HCl were often the dominant forms of reactive gas-phase chlorine compounds, with ClNO2 routinely reaching >1.5 ppb in the polluted outflow of the eastern U.S. urban corridor. ClNO2 often becomes a substantial fraction (~30%) of NOz (NOz = NOy – NOx) in these plumes at night. Preliminary analyses suggests that ClNO2 production is most efficient in the polluted marine boundary layer, with yields approaching unity and the evolution of nighttime ClNO2 highly correlated with that of HNO3 and particulate nitrate. However, ClNO2 production was observed throughout the region and a significant source of reactive chlorine from coal-fired power plants was directly confirmed with measurements of HCl strongly correlated with SO2. In addition, there is some evidence that biomass or biofuel combustion is a source of reactive chlorine that can lead to ClNO2 production. Examples of the nocturnal and diel evolution of reactive chlorine species are given, and we show to our knowledge the first measurements of chlorine nitrate (ClONO2) in the polluted mid-latitude marine boundary layer.
