Abstract
Very short-lived substances (VSLS), including dichloromethane (CH 2 Cl 2 ), chloroform (CHCl 3 ), perchloroethylene (C 2 Cl 4 ), and 1,2-dichloroethane (C 2 H 4 Cl 2 ), are a stratospheric chlorine source and therefore contribute to ozone depletion. We quantify stratospheric chlorine trends from these VSLS (VSLCl tot ) using a chemical transport model and atmospheric measurements, including novel high-altitude aircraft data from the NASA VIRGAS (2015) and POSIDON (2016) missions. We estimate VSLCl tot increased from 69 (±14) parts per trillion (ppt) Cl in 2000 to 111 (±22) ppt Cl in 2017, with >80% delivered to the stratosphere through source gas injection, and the remainder from product gases. The modeled evolution of chlorine source gas injection agrees well with historical aircraft data, which corroborate reported surface CH 2 Cl 2 increases since the mid-2000s. The relative contribution of VSLS to total stratospheric chlorine increased from ~2% in 2000 to ~3.4% in 2017, reflecting both VSLS growth and decreases in long-lived halocarbons. We derive a mean VSLCl tot growth rate of 3.8 (±0.3) ppt Cl/year between 2004 and 2017, though year-to-year growth rates are variable and were small or negative in the period 2015–2017. Whether this is a transient effect, or longer-term stabilization, requires monitoring. In the upper stratosphere, the modeled rate of HCl decline (2004–2017) is −5.2% per decade with VSLS included, in good agreement to ACE satellite data (−4.8% per decade), and 15% slower than a model simulation without VSLS. Thus, VSLS have offset a portion of stratospheric chlorine reductions since the mid-2000s.
| Original language | English (US) |
|---|---|
| Journal | Journal of Geophysical Research: Atmospheres |
| DOIs | |
| State | Published - Jan 1 2019 |
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Keywords
- chlorine
- chloroform
- dichloromethane
- ozone
- stratosphere
- VSLS
ASJC Scopus subject areas
- Geophysics
- Forestry
- Oceanography
- Aquatic Science
- Ecology
- Water Science and Technology
- Soil Science
- Geochemistry and Petrology
- Earth-Surface Processes
- Atmospheric Science
- Space and Planetary Science
- Earth and Planetary Sciences (miscellaneous)
- Palaeontology
Cite this
Recent Trends in Stratospheric Chlorine From Very Short-Lived Substances. / Hossaini, Ryan; Atlas, Elliot L; Dhomse, Sandip S.; Chipperfield, Martyn P.; Bernath, Peter F.; Fernando, Anton M.; Mühle, Jens; Leeson, Amber A.; Montzka, Stephen A.; Feng, Wuhu; Harrison, Jeremy J.; Krummel, Paul; Vollmer, Martin K.; Reimann, Stefan; O'Doherty, Simon; Young, Dickon; Maione, Michela; Arduini, Jgor; Lunder, Chris R.
In: Journal of Geophysical Research: Atmospheres, 01.01.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Recent Trends in Stratospheric Chlorine From Very Short-Lived Substances
AU - Hossaini, Ryan
AU - Atlas, Elliot L
AU - Dhomse, Sandip S.
AU - Chipperfield, Martyn P.
AU - Bernath, Peter F.
AU - Fernando, Anton M.
AU - Mühle, Jens
AU - Leeson, Amber A.
AU - Montzka, Stephen A.
AU - Feng, Wuhu
AU - Harrison, Jeremy J.
AU - Krummel, Paul
AU - Vollmer, Martin K.
AU - Reimann, Stefan
AU - O'Doherty, Simon
AU - Young, Dickon
AU - Maione, Michela
AU - Arduini, Jgor
AU - Lunder, Chris R.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Very short-lived substances (VSLS), including dichloromethane (CH 2 Cl 2 ), chloroform (CHCl 3 ), perchloroethylene (C 2 Cl 4 ), and 1,2-dichloroethane (C 2 H 4 Cl 2 ), are a stratospheric chlorine source and therefore contribute to ozone depletion. We quantify stratospheric chlorine trends from these VSLS (VSLCl tot ) using a chemical transport model and atmospheric measurements, including novel high-altitude aircraft data from the NASA VIRGAS (2015) and POSIDON (2016) missions. We estimate VSLCl tot increased from 69 (±14) parts per trillion (ppt) Cl in 2000 to 111 (±22) ppt Cl in 2017, with >80% delivered to the stratosphere through source gas injection, and the remainder from product gases. The modeled evolution of chlorine source gas injection agrees well with historical aircraft data, which corroborate reported surface CH 2 Cl 2 increases since the mid-2000s. The relative contribution of VSLS to total stratospheric chlorine increased from ~2% in 2000 to ~3.4% in 2017, reflecting both VSLS growth and decreases in long-lived halocarbons. We derive a mean VSLCl tot growth rate of 3.8 (±0.3) ppt Cl/year between 2004 and 2017, though year-to-year growth rates are variable and were small or negative in the period 2015–2017. Whether this is a transient effect, or longer-term stabilization, requires monitoring. In the upper stratosphere, the modeled rate of HCl decline (2004–2017) is −5.2% per decade with VSLS included, in good agreement to ACE satellite data (−4.8% per decade), and 15% slower than a model simulation without VSLS. Thus, VSLS have offset a portion of stratospheric chlorine reductions since the mid-2000s.
AB - Very short-lived substances (VSLS), including dichloromethane (CH 2 Cl 2 ), chloroform (CHCl 3 ), perchloroethylene (C 2 Cl 4 ), and 1,2-dichloroethane (C 2 H 4 Cl 2 ), are a stratospheric chlorine source and therefore contribute to ozone depletion. We quantify stratospheric chlorine trends from these VSLS (VSLCl tot ) using a chemical transport model and atmospheric measurements, including novel high-altitude aircraft data from the NASA VIRGAS (2015) and POSIDON (2016) missions. We estimate VSLCl tot increased from 69 (±14) parts per trillion (ppt) Cl in 2000 to 111 (±22) ppt Cl in 2017, with >80% delivered to the stratosphere through source gas injection, and the remainder from product gases. The modeled evolution of chlorine source gas injection agrees well with historical aircraft data, which corroborate reported surface CH 2 Cl 2 increases since the mid-2000s. The relative contribution of VSLS to total stratospheric chlorine increased from ~2% in 2000 to ~3.4% in 2017, reflecting both VSLS growth and decreases in long-lived halocarbons. We derive a mean VSLCl tot growth rate of 3.8 (±0.3) ppt Cl/year between 2004 and 2017, though year-to-year growth rates are variable and were small or negative in the period 2015–2017. Whether this is a transient effect, or longer-term stabilization, requires monitoring. In the upper stratosphere, the modeled rate of HCl decline (2004–2017) is −5.2% per decade with VSLS included, in good agreement to ACE satellite data (−4.8% per decade), and 15% slower than a model simulation without VSLS. Thus, VSLS have offset a portion of stratospheric chlorine reductions since the mid-2000s.
KW - chlorine
KW - chloroform
KW - dichloromethane
KW - ozone
KW - stratosphere
KW - VSLS
UR - http://www.scopus.com/inward/record.url?scp=85060538277&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85060538277&partnerID=8YFLogxK
U2 - 10.1029/2018JD029400
DO - 10.1029/2018JD029400
M3 - Article
JO - Journal of Geophysical Research: Oceans
JF - Journal of Geophysical Research: Oceans
SN - 2169-9275
ER -