Significant concentrations of nitryl chloride observed in rural continental Europe associated with the influence of sea salt chloride and anthropogenic emissions

• Published in: Geophysical research letters Vol. 39; no. 10
• Main Authors: Phillips, G. J., Tang, M. J., Thieser, J., Brickwedde, B., Schuster, G., Bohn, B., Lelieveld, J., Crowley, J. N.
• Format: Journal Article
• Language: English
• Published: Washington, DC Blackwell Publishing Ltd 28.05.2012; American Geophysical Union; John Wiley & Sons, Inc
• Subjects: Air masses; Air pollution; Anthropogenic factors; Atmospheric sciences; Chlorides; chlorine radicals; cims; Earth sciences; Earth, ocean, space; Emission measurements; Emissions; Exact sciences and technology; Geophysics; halogens; Mixing ratios; Morning; nitryl chloride; Nitryl chlorides; Ozone; Photolysis; Rural; Troposphere; Central Europe; Europe; Germany; chlorides; Night; concentration; air; halides; ozone; Sea salt; Production rate; Photolysis; Rate constant; Nitrogen dioxide; Mixing ratio; rural areas; Anthropogenic factor
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2012GL051912

We present the first measurements of nitryl chloride (ClNO2) over continental Europe. Significant quantities of ClNO2, up to 800 pptv, were measured at a mountaintop field site in Hessen, southwest Germany. ClNO2 was detected during the majority of nights between the 15th August and 16th September 2011, its largest mixing ratios being associated with air masses influenced by sea salt and anthropogenic NOx emissions. ClNO2 persisted in measurable quantities until early afternoons on days with low photolysis frequencies. As a consequence, early morning production rates of Cl atoms could significantly exceed the production of OH via ozone photolysis, likely leading to increased O3 production. Key Points Nitryl chloride exists in significant mixing fractions over Europe Nitryl chloride is likely of marine origin, deriving from aged sea salt and N2O5 Nitryl chloride is a significant radical source in early morning