Description: Chemical and meteorological influences on the lifetime of NO3 at a semi-rural mountain site during PARADE

This title appears in the Scientific Report : 2016

Chemical and meteorological influences on the lifetime of NO3 at a semi-rural mountain site during PARADE

Through measurements of NO2, O3 and NO3 during the PARADE campaign (PArticles and RAdicals, Diel observations of mEchanisms of oxidation) in the German Taunus mountains we derive nighttime steady-state lifetimes (τss) of NO3 and N2O5. During some nights, high NO3 (∼ 200 pptv) and N2O5 (∼ 1 ppbv) mix...

Personal Name(s):	Sobanski, N.
	Tang, M. J. / Thieser, J. / Schuster, G. / Pöhler, D. / Fischer, H. / Song, W. / Sauvage, C. / Williams, J. / Fachinger, J. / Berkes, Florian / Hoor, P. / Platt, U. / Lelieveld, J. / Crowley, J. N. (Corresponding author)
Contributing Institute:	Troposphäre; IEK-8
Published in:	Atmospheric chemistry and physics, 16 (2016) 8, S. 4867 - 4883
Imprint:	Katlenburg-Lindau EGU 2016
DOI:	10.5194/acp-16-4867-2016
Document Type:	Journal Article
Research Program:	Tropospheric trace substances and their transformation processes
Link:	OpenAccess OpenAccess
	Publikationsportal JuSER

Please use the identifier: http://dx.doi.org/10.5194/acp-16-4867-2016 in citations.
Please use the identifier: http://hdl.handle.net/2128/11203 in citations.

Through measurements of NO2, O3 and NO3 during the PARADE campaign (PArticles and RAdicals, Diel observations of mEchanisms of oxidation) in the German Taunus mountains we derive nighttime steady-state lifetimes (τss) of NO3 and N2O5. During some nights, high NO3 (∼ 200 pptv) and N2O5 (∼ 1 ppbv) mixing ratios were associated with values of τss that exceeded 1 h for NO3 and 3 h for N2O5 near the ground. Such long boundary-layer lifetimes for NO3 and N2O5 are usually only encountered in very clean/unreactive air masses, whereas the PARADE measurement site is impacted by both biogenic emissions from the surrounding forest and anthropogenic emissions from the nearby urbanised/industrialised centres. Measurement of several trace gases which are reactive towards NO3 indicates that the inferred lifetimes are significantly longer than those calculated from the summed loss rate. Several potential causes for the apparently extended NO3 and N2O5 lifetimes are examined, including additional routes to formation of NO3 and the presence of a low-lying residual layer. Overall, the most likely cause of the anomalous lifetimes are related to the meteorological conditions, though additional NO3 formation due to reactions of Criegee intermediates may contribute.