Preprints
https://doi.org/10.5194/acp-2020-782
https://doi.org/10.5194/acp-2020-782

  08 Dec 2020

08 Dec 2020

Review status: this preprint is currently under review for the journal ACP.

Diurnal evolution of total column and surface atmospheric ammonia in the megacity of Paris, France, during an intense springtime pollution episode

Rebecca D. Kutzner1, Juan Cuesta1, Pascale Chelin1, Jean-Eudes Petit2,3, Mokhtar Ray1, Xavier Landsheere1, Benoît Tournadre1,a, Jean-Charles Dupont4, Amandine Rosso5, Frank Hase6, Johannes Orphal6, and Matthias Beekmann1 Rebecca D. Kutzner et al.
  • 1Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), UMR CNRS 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre Simon Laplace (IPSL), Créteil, France
  • 2Laboratoire des Sciences du Climat et de l’Environnement, UMR 8212, CEA/Orme des Merisiers, 91191 Gifsur-Yvette, France
  • 3INERIS, Parc Technologique ALATA, 60750 Verneuil-en-Halatte, France
  • 4Institut Pierre-Simon Laplace, École Polytechnique, UVSQ, Université Paris-Saclay, 91128 Palaiseau, France
  • 5AIRPARIF, Agence de surveillance de la qualité de l'air, Paris, France
  • 6Institut für Meteorologie und Klimaforschung (IMK), Karlsruher Institut für Technologie (KIT), Karlsruhe, Germany
  • aNew affiliation: Centre for Observation, Impacts, Energy, Mines ParisTech, Sophia Antipolis Cedex, France

Abstract. Ammonia (NH3) is a key precursor for the formation of atmospheric secondary inorganic particles, such as ammonium nitrate and sulfate. Although the chemical processes associated with the gas-to-particle conversion are well known, atmospheric concentrations of gaseous ammonia are still scarcely characterized. This information is however critical especially for processes concerning the equilibrium between ammonia and ammonium nitrate, due to the semi-volatile character of the latter one. This study presents an analysis of the diurnal cycle of atmospheric ammonia during a pollution event over the Paris megacity region in spring 2012 (five days in late March 2012). Our objective is to analyze the link between the diurnal evolution of surface NH3 concentrations and its integrated column abundance, meteorological variables and relevant chemical species involved in gas/particle partitioning. For this, we implement an original approach based on the combined use of surface and total column ammonia measurements. These last ones are derived from ground-based remote-sensing measurements performed by the Observations of the Atmosphere by Solar Infrared Spectroscopy (OASIS) Fourier transform infrared observatory at an urban site over the southeastern suburbs of the Paris megacity. This analysis considers the following meteorological variables relevant to the ammonia pollution event: temperature, relative humidity, wind speed and direction and vertical dilution in the atmospheric boundary layer. Moreover, we study the partitioning between ammonia and ammonium particles from concomitant measurements of total particulate matter (PM) and ammonium (NH4+) concentrations at the surface. We identify the origin of the pollution event as local emissions at the beginning of the analyzed period and advection of pollution from the Benelux and west Germany region by the end. Our results show a clearly different diurnal behavior of atmospheric ammonia concentrations at the surface and those vertically integrated over the total atmospheric column. Surface concentrations remain relatively stable during the day, while total column abundances show a minimum value in the morning and rise steadily to reach a relative maximum in the late afternoon during the spring pollution event. These differences are mainly explained by vertical mixing within the boundary layer, as suggested by ground-based measurements of vertical profiles of aerosol backscatter, used as tracer of the vertical distribution of pollutants in the atmospheric boundary layer. Indeed, the afternoon enhancement of ammonia clearly seen by OASIS for the whole atmospheric column is barely depicted by surface concentrations, as the latter are strongly affected by vertical dilution within the rising boundary layer. Moreover, the concomitant occurrence of a decrease of ammonium particle concentrations and an increase of gaseous ammonia abundance suggests the volatilization of particles for forming ammonia. Furthermore, surface observations may also suggest night-time formation of ammonium particles from gas-to-particle conversion, for relative humidity levels higher than the deliquescence point of ammonium nitrate.

Rebecca D. Kutzner et al.

 
Status: open (extended)
Status: open (extended)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Rebecca D. Kutzner et al.

Rebecca D. Kutzner et al.

Viewed

Total article views: 193 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
129 61 3 193 14 7 6
  • HTML: 129
  • PDF: 61
  • XML: 3
  • Total: 193
  • Supplement: 14
  • BibTeX: 7
  • EndNote: 6
Views and downloads (calculated since 08 Dec 2020)
Cumulative views and downloads (calculated since 08 Dec 2020)

Viewed (geographical distribution)

Total article views: 284 (including HTML, PDF, and XML) Thereof 282 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 11 Apr 2021
Download
Short summary
Our work investigates the diurnal evolution of atmospheric ammonia concentrations during a major pollution event. It analyses it in regard of both chemical (gas/particle conversion) and physical (vertical mixing, meteorology) processes in the atmosphere. These mechanisms are key for understanding the evolution of the physico-chemical state of the atmosphere and therefore it clearly fits in the scope of the ACP journal.
Altmetrics