Greenland active-layer soils eat permafrost VOCs
Active-layer soils from Disko Island and Kangerlussuaq consume most tested VOCs, likely microbially, before they can escape to the air.
Source
The active layer soils of Greenlandic permafrost areas can function as important sinks for volatile organic compounds
What they did
Authors incubated active-layer soils from two Greenland sites at several depths in a PTR-ToF-MS chamber, measured emission blends and uptake of 12 target VOCs, and tested water addition versus field moisture.
What they found
Soils consumed all 12 VOCs at 10 cm (acetaldehyde failed in some deeper samples). Highest uptake was for benzyl alcohol, isoprene, and linalool. Depth mattered less than site/glacier proximity. Wetting often increased uptake, but compound-specific patterns argue against pure dissolution; microbes are the likely sink, analogous to methane oxidation.
The limits
What it doesn't show
Short incubations cannot separate adsorption from metabolism or prove no later re-emission. Lab VOC concentrations may differ from soil pores. Two Greenland locales do not map the pan-Arctic, and thaw-driven emission fluxes were not quantified in situ.
Key terms
- Active layer
- Seasonally thawing soil above permafrost that hosts plants and microbes.
- VOC
- Volatile organic compound that can form SOA and oxidize to CO2.
- Uptake coefficient
- Measure of how efficiently a soil consumes a given VOC.
- PTR-ToF-MS
- Proton-transfer-reaction time-of-flight mass spectrometry for VOC fluxes.
- Permafrost carbon
- Up to ~1700 Pg C frozen in permafrost, about twice atmospheric carbon.
Flashcards
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Quiz yourself
Greenland active-layer soils in this study mainly:
Common questions
Are active-layer soils only VOC sources?
No; they can be strong sinks for VOCs leaking from thawing permafrost.
Is uptake just water dissolving gases?
Unlikely: coefficients differ by compound and wetting does not always help soluble species.
Which VOCs were taken up fastest?
Benzyl alcohol, isoprene, and linalool at 10 cm.
Why does this matter for climate?
It can filter reactive carbon that would otherwise affect OH and aerosols.
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