TY - JOUR

T1 - Ground and Airborne U.K. Measurements of Nitryl Chloride

T2 - An Investigation of the Role of Cl Atom Oxidation at Weybourne Atmospheric Observatory

AU - Bannan, Thomas J.

AU - Bacak, Asan

AU - Le Breton, Michael

AU - Flynn, Michael

AU - Ouyang, Bin

AU - McLeod, Matthew

AU - Jones, Rod

AU - Malkin, Tamsin L.

AU - Whalley, Lisa K.

AU - Heard, Dwayne E.

AU - Bandy, Brian

AU - Khan, M. Anwar H.

AU - Shallcross, Dudley E.

AU - Percival, Carl J.

PY - 2017/10/27

Y1 - 2017/10/27

N2 - Nitryl chloride (ClNO2) measurements from the Weybourne Atmospheric Observatory (WAO) are reported from March to April 2013 using a quadruple chemical ionization mass spectrometer with the I− ionization scheme. WAO is a rural coastal site with generally low NOx concentrations, a type of location poorly studied for ClNO2 production. Concentrations of ClNO2 exceeded that of the limit of detection (0.8 ppt) on each night of the campaign, as did concentrations of N2O5, which was also measured simultaneously with the Cambridge Broadband Cavity Enhanced Absorption Spectrometer. A peak concentration of 65 ppt of ClNO2 is reported here. Vertical profiles of ClNO2 from early- to middle-morning flights in close proximity to WAO are also reported, showing elevated concentrations at low altitude. The photolysis of observed ClNO2 and a box model utilizing the Master Chemical Mechanism modified to include chlorine chemistry was used to calculate Cl atom concentrations. This model utilized numerous VOCs from the second Tropospheric Organic Chemistry project in 2004, at the same location and time of year. From this the relative importance of the oxidation of three groups of measured VOCs (alkanes, alkenes, and alkynes) by OH radicals, Cl atoms, and O3 is compared. Cl atom oxidation was deemed generally insignificant at this time and location for total oxidation due to the much lower concentration of ClNO2 observed, even following the night of greatest ClNO2 production.

AB - Nitryl chloride (ClNO2) measurements from the Weybourne Atmospheric Observatory (WAO) are reported from March to April 2013 using a quadruple chemical ionization mass spectrometer with the I− ionization scheme. WAO is a rural coastal site with generally low NOx concentrations, a type of location poorly studied for ClNO2 production. Concentrations of ClNO2 exceeded that of the limit of detection (0.8 ppt) on each night of the campaign, as did concentrations of N2O5, which was also measured simultaneously with the Cambridge Broadband Cavity Enhanced Absorption Spectrometer. A peak concentration of 65 ppt of ClNO2 is reported here. Vertical profiles of ClNO2 from early- to middle-morning flights in close proximity to WAO are also reported, showing elevated concentrations at low altitude. The photolysis of observed ClNO2 and a box model utilizing the Master Chemical Mechanism modified to include chlorine chemistry was used to calculate Cl atom concentrations. This model utilized numerous VOCs from the second Tropospheric Organic Chemistry project in 2004, at the same location and time of year. From this the relative importance of the oxidation of three groups of measured VOCs (alkanes, alkenes, and alkynes) by OH radicals, Cl atoms, and O3 is compared. Cl atom oxidation was deemed generally insignificant at this time and location for total oxidation due to the much lower concentration of ClNO2 observed, even following the night of greatest ClNO2 production.

KW - halogen chemistry

KW - tropospheric oxidation

U2 - 10.1002/2017JD026624

DO - 10.1002/2017JD026624

M3 - Journal article

AN - SCOPUS:85031672868

VL - 122

SP - 11,154-11,165

JO - Journal of Geophysical Research: Atmospheres

JF - Journal of Geophysical Research: Atmospheres

SN - 2169-897X

IS - 20

ER -