Volatile organic compounds in Arctic snow: concentrations and implications for atmospheric processes

Area of Science:

• Atmospheric Chemistry
• Environmental Science
• Arctic Research

Background:

• The role of snowpack volatile organic compounds (VOC) in atmospheric processes is poorly understood.
• Limited methodology and data hinder research on VOCs in snow.

Purpose of the Study:

• To measure halogenated, aromatic, and oxygenated VOCs in Arctic snowpack.
• To investigate the contribution of snowpack VOCs to atmospheric oxidation and aerosol formation.

Main Methods:

• Solid phase micro-extraction (SPME) gas chromatography with flame ionization detection (GC-FID) was used.
• Measurements were conducted in Alert, NU, Canada, and Barrow, AK, USA.
• Air mass source regions were analyzed using back trajectory data.

Main Results:

• Maximum snow VOC concentrations reached 39 ± 6 μg L(-1) (styrene) in Alert and 1.3 ± 0.1 μg L(-1) (acetophenone) in Barrow.
• Trichloroethene and benzene showed depletion events linked to air mass changes.
• Bromoform in frost flowers averaged 0.19 ± 0.04 μg L(-1), suggesting potential bromine generation.

Conclusions:

• Snowpack VOCs have significant concentrations, potentially impacting atmospheric oxidation and aerosol formation.
• Snow profiles indicate surface enrichment of most VOC compounds.
• Frost flowers may contribute to bromine release through photolysis.