Growth in stratospheric chlorine from short-lived chemicals not controlled by the Montreal Protocol

R. Hossaini, M. P. Chipperfield, A. Saiz-Lopez, J. J. Harrison, R. Von Glasow, R. Sommariva, E. Atlas, M. Navarro, S. A. Montzka, W. Feng, S. Dhomse, C. Harth, J. Mühle, C. Lunder, S. O'Doherty, D. Young, S. Reimann, M. K. Vollmer, P. B. Krummel, P. F. Bernath

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

We have developed a chemical mechanism describing the tropospheric degradation of chlorine containing very short-lived substances (VSLS). The scheme was included in a global atmospheric model and used to quantify the stratospheric injection of chlorine from anthropogenic VSLS (ClyVSLS) between 2005 and 2013. By constraining the model with surface measurements of chloroform (CHCl3), dichloromethane (CH2Cl2), tetrachloroethene (C2Cl4), trichloroethene (C2HCl3), and 1,2-dichloroethane (CH2ClCH2Cl), we infer a 2013 ClyVSLS mixing ratio of 123 parts per trillion (ppt). Stratospheric injection of source gases dominates this supply, accounting for ∼83% of the total. The remainder comes from VSLS-derived organic products, phosgene (COCl2, 7%) and formyl chloride (CHClO, 2%), and also hydrogen chloride (HCl, 8%). Stratospheric ClyVSLS increased by ∼52% between 2005 and 2013, with a mean growth rate of 3.7 ppt Cl/yr. This increase is due to recent and ongoing growth in anthropogenic CH2Cl2 - the most abundant chlorinated VSLS not controlled by the Montreal Protocol.

Original languageEnglish (US)
Pages (from-to)4573-4580
Number of pages8
JournalGeophysical Research Letters
Volume42
Issue number11
DOIs
StatePublished - Jun 16 2015

    Fingerprint

Keywords

  • Montreal Protocol
  • VSLS
  • dichloromethane
  • ozone
  • phosgene
  • stratosphere

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

Cite this

Hossaini, R., Chipperfield, M. P., Saiz-Lopez, A., Harrison, J. J., Von Glasow, R., Sommariva, R., Atlas, E., Navarro, M., Montzka, S. A., Feng, W., Dhomse, S., Harth, C., Mühle, J., Lunder, C., O'Doherty, S., Young, D., Reimann, S., Vollmer, M. K., Krummel, P. B., & Bernath, P. F. (2015). Growth in stratospheric chlorine from short-lived chemicals not controlled by the Montreal Protocol. Geophysical Research Letters, 42(11), 4573-4580. https://doi.org/10.1002/2015GL063783