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: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Discussion papers
https://doi.org/10.5194/acp-2019-943
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2019-943
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.

Submitted as: research article 06 Dec 2019

Submitted as: research article | 06 Dec 2019

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).

Consumption of CH3Cl, CH3Br and CH3I and emission of CHCl3, CHBr3 and CH2Br2 from a retreating Arctic glacier's forefield

Moya L. Macdonald1, Jemma L. Wadham1, Dickon Young2, Chris R. Lunder3, Ove Hermansen3, Guillaume Lamarche-Gagnon1, and Simon O'Doherty2 Moya L. Macdonald et al.
  • 1School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
  • 2School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK
  • 3Norwegian Institute for Air Research (NILU), Kjeller, NO-2027, Norway

Abstract. The Arctic is one of the most rapidly warming regions of the Earth, with predicted temperature increases of 5–7 °C and the accompanying extensive retreat of Arctic glacial systems by 2100. This will reveal new proglacial land surfaces for microbial colonisation, ultimately succeeding to tundra over decades to centuries. An unexplored dimension to these changes is the impact upon the emission and consumption of halogenated organic compounds (halocarbons) from proglacial land surfaces. Halocarbons are involved in several important atmospheric processes, including ozone destruction, and despite considerable research, uncertainties remain in the natural cycles of some of these compounds. Using flux chambers, we measured halocarbon fluxes from proglacial land surfaces spanning recently-exposed sediments (< 10 years), to approximately 1950 year old tundra in front of a High Arctic glacier. Proglacial land surfaces were found to consume methyl chloride (CH3Cl) and methyl bromide (CH3Br), with both consumption and emission of methyl iodide (CH3I) observed. The largest consumption rates of these compounds occurred at the oldest, vegetated, tundra sites (−126 ± 4, −1.8 ± 0.04 and −0.13 ± 0.03 nmol m−2 d−1, respectively for CH3Cl, CH3Br and CH3I). However, similar consumption rates were recorded at much younger sites with little soil development, but with the presence of extensive cyanobacterial mats (means of −106 ± 7, −1.7 ± 0.1, −0.01 ± 0.03 nmol m−2 d−1 for CH3Cl, CH3Br and CH3I). Emission of chloroform (CHCl3), bromoform (CHBr3) and dibromomethane (CH2Br2) was detected across the forefield, with the highest emission of CHCl3 from cyanobacterial mats (106 ± 42 nmol m−2 d−1), CHBr3 from bare sediment adjacent to the mats (0.7 ± 0.3 nmol CHBr3 m−2 d−1) and CH2Br2 from the vegetated tundra (mean 0.8 ± 0.3 nmol m−2 d−1). We have demonstrated that proglacial surfaces can consume and emit halocarbons despite their young age and low soil development. With future glacial retreat and the expansion of these surfaces, these fluxes may become more important in the future.

Moya L. Macdonald et al.
Interactive discussion
Status: open (until 31 Jan 2020)
Status: open (until 31 Jan 2020)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Moya L. Macdonald et al.
Data sets

Gas fluxes and biological and physiochemical measurements made across an Arctic forefield. M. L. Macdonald, J. L. Wadham, D. Young, C. Lunder, O. Hermansen, G. Lamarche-Gagnon, and S. O'Doherty https://doi.org/10.6084/m9.figshare.8081129

Moya L. Macdonald et al.
Viewed  
Total article views: 178 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
142 33 3 178 0 0
  • HTML: 142
  • PDF: 33
  • XML: 3
  • Total: 178
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 06 Dec 2019)
Cumulative views and downloads (calculated since 06 Dec 2019)
Viewed (geographical distribution)  
Total article views: 99 (including HTML, PDF, and XML) Thereof 99 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: 24 Jan 2020
Publications Copernicus
Download
Short summary
Climate change has caused glaciers in the Arctic to shrink, uncovering new soils. We used field measurements to study the exchange of a group of gases involved in ozone destruction, called halocarbons, between these new soils and the atmosphere. We found that mats of cyanobacteria, early colonisers of soils, are linked to a larger than expected exchange of halocarbons with the atmosphere. We also found that gases which are commonly thought to be marine in origin were released from these soils.
Climate change has caused glaciers in the Arctic to shrink, uncovering new soils. We used field...
Citation