Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.414 IF 5.414
  • IF 5-year value: 5.958 IF 5-year
    5.958
  • CiteScore value: 9.7 CiteScore
    9.7
  • SNIP value: 1.517 SNIP 1.517
  • IPP value: 5.61 IPP 5.61
  • SJR value: 2.601 SJR 2.601
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 191 Scimago H
    index 191
  • h5-index value: 89 h5-index 89
Preprints
https://doi.org/10.5194/acp-2020-266
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2020-266
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  27 Mar 2020

27 Mar 2020

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

Aerosol acidity and liquid water content regulate the dry deposition of inorganic reactive nitrogen

Athanasios Nenes1,2, Spyros N. Pandis1,3, Maria Kanakidou1,4, Armistead Russell5, Shaojie Song6, Petros Vasilakos5, and Rodney J. Weber7 Athanasios Nenes et al.
  • 1Institute for Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, GR-26504, Greece
  • 2School of Architecture, Civil & Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
  • 3Department of Chemical Engineering, University of Patras, GR-26504, Greece
  • 4Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Voutes, Heraklion Crete, 70013, Greece
  • 5School of Civil & Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
  • 6School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
  • 7School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA

Abstract. Ecosystem productivity is strongly modulated by the atmospheric deposition of inorganic reactive nitrogen (the sum of ammonium and nitrate). The individual contributions of ammonium and nitrate vary considerably over space and time, giving rise to complex patterns of nitrogen deposition. In the absence of rain, much of this complexity is driven by the large difference between the dry deposition velocity of nitrogen-containing molecules in the gas or condensed phase. Here we quantify how aerosol liquid water and acidity, through their impact on gas-to-particle partitioning, modulate the deposition velocity of NH3 and HNO3 individually, while simultaneously affecting the dry deposition of inorganic reactive nitrogen. Four regimes of deposition velocity emerge: i) HNO3-fast, NH3-slow, ii) HNO3-slow, NH3-fast, iii) HNO3-fast, NH3-fast, and, iv) HNO3-slow, NH3-slow. Conditions that favor partitioning of species to the aerosol phase strongly reduce the deposition of reactive nitrogen species and promote their accumulation in the boundary layer and potential for long-range transport. Application of this framework to select locations around the world reveals fundamentally important insights: The dry deposition of total ammonia displays little sensitivity to pH and liquid water variations, except under conditions of extreme acidity and/or low aerosol liquid water content. The dry deposition of total nitric acid, on the other hand, is quite variable, with maximum deposition velocities (close to gas-deposition rates) found in the Eastern US and minimum velocities in Northern Europe and China. In the latter case, the low deposition velocity leads to up to 10-fold increases in PM2.5 nitrate aerosol, thus contributing to the high PM2.5 levels observed during haze episodes. In this light, aerosol pH and associated liquid water content can be considered as control parameters that drive dry deposition flux and can accelerate the accumulation of aerosol contributing to intense haze events throughout the globe.

Athanasios Nenes et al.

Interactive discussion

Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Athanasios Nenes et al.

Athanasios Nenes et al.

Viewed

Total article views: 462 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
306 145 11 462 8 14
  • HTML: 306
  • PDF: 145
  • XML: 11
  • Total: 462
  • BibTeX: 8
  • EndNote: 14
Views and downloads (calculated since 27 Mar 2020)
Cumulative views and downloads (calculated since 27 Mar 2020)

Viewed (geographical distribution)

Total article views: 380 (including HTML, PDF, and XML) Thereof 380 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Saved

No saved metrics found.

Discussed

No discussed metrics found.
Latest update: 07 Aug 2020
Publications Copernicus
Download
Short summary
Ecosystems and air quality are affected by the dry deposition of inorganic reactive nitrogen (Nr, the sum of ammonium and nitrate). Its large variability is driven by the large difference in deposition velocity of N when in the gas or particle phase. Here we show that aerosol liquid water and acidity, by affecting gas-particle partitioning, modulate the dry deposition velocity of NH3, HNO3 and Nr worldwide. These effects explain the rapid accumulation of nitrate aerosol during haze events.
Ecosystems and air quality are affected by the dry deposition of inorganic reactive nitrogen...
Citation