A41A-0010
Measurement of pernitric acid (HO2NO2) using chemical ionization mass spectrometry (CIMS) with I-·H2O as the reagent ions: instrumentation and observations

Thursday, 17 December 2015
Poster Hall (Moscone South)
Dexian Chen1, L Gregory Huey2, David Tanner2, Nga Lee Ng2, Jianfeng Li2, Jack E Dibb3 and Yuhang Wang1, (1)Georgia Institute of Technology Main Campus, School of Earth and Atmospheric Sciences, Atlanta, GA, United States, (2)Georgia Institute of Technology, Atlanta, GA, United States, (3)University of New Hampshire Main Campus, Durham, NH, United States
Abstract:
Peroxynitric acid (HO2NO2) is formed by the association reaction of HO2 and NO2, which couples both the HOx (HO2+OH) and NOx (=NO2+NO) families. The thermal decomposition at higher temperatures is sufficiently fast that HO2NO2 is in steady state with HO2 and NO2. This allows HO2 levels to be inferred from HO2NO2 observations. In Polar Regions and higher altitudes, significant levels of HO2NO2 can build up and influences local HOx and NOx photochemistry. Here, we present an in situ measurement technique of HO2NO2 based on chemical ionization mass spectrometry (CIMS) using the reagent ion I- and its hydrated form I-·H2O, together with our calibration technique for HO2NO2 measurements. We will also present observations of HO2NO2: (1) in a polar boundary layer on top of the Greenland Ice Sheet during summer 2011, and (2) in an urban boundary layer in metropolitan Atlanta during winter 2014. The local chemistry of HO2NO2 at Summit will be evaluated. The local HO2 in Atlanta will be inferred and assessed with models.

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