Peroxynitric acid (HO2NO2) measurements during the UBWOS 2013 and 2014 studies using iodide ion chemical ionization mass spectrometry

Autor: P. R. Veres, J. M. Roberts, R. J. Wild, P. M. Edwards, S. S. Brown, T. S. Bates, P. K. Quinn, J. E. Johnson, R. J. Zamora, J. de Gouw
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Atmospheric Chemistry and Physics, Vol 15, Iss 14, Pp 8101-8114 (2015)
Druh dokumentu: article
ISSN: 1680-7316
1680-7324
DOI: 10.5194/acp-15-8101-2015
Popis: In this paper laboratory work is documented establishing iodide ion chemical ionization mass spectrometry (I- CIMS) as a sensitive method for the unambiguous detection of peroxynitric acid (HO2NO2; PNA). A dynamic calibration source for HO2NO2, HO2, and HONO was developed and calibrated using a novel total NOy cavity ring-down spectroscopy (CaRDS) detector. Photochemical sources of these species were used for the calibration and validation of the I- CIMS instrument for detection of HO2NO2. Ambient observations of HO2NO2 using I- CIMS during the 2013 and 2014 Uintah Basin Wintertime Ozone Study (UBWOS) are presented. Strong inversions leading to a build-up of many primary and secondary pollutants as well as low temperatures drove daytime HO2NO2 as high as 1.5 ppbv during the 2013 study. A comparison of HO2NO2 observations to mixing ratios predicted using a chemical box model describing an ozone formation event observed during the 2013 wintertime shows agreement in the daily maxima HO2NO2 mixing ratio, but a differences of several hours in the timing of the observed maxima. Observations of vertical gradients suggest that the ground snow surface potentially serves as both a net sink and source of HO2NO2 depending on the time of day. Sensitivity tests using a chemical box model indicate that the lifetime of HO2NO2 with respect to deposition has a non-negligible impact on ozone production rates on the order of 10 %.
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