Ice-melt period dominates annual carbon dioxide evasion from clear-water Arctic lakes

Current estimates of carbon dioxide (CO2) evasion from Arctic lakes are highly uncertain because few studies integrate seasonal variability, specifically evasion during spring ice-melt. We quantified annual CO2 evasion for 14 clear-water Arctic lakes in Northern Sweden through mass balance (ice-melt period) and high-frequency loggers (open-water period). On average, 80% (SD: +/- 18) of annual CO2 evasion occurred within 10 d following ice-melt. The contribution of the ice-melt period to annual CO2 evasion was high compared to earlier studies of Arctic lakes (47% +/- 32%). Across all lakes, the proportion of ice-melt : annual CO2 evasion was negatively related to the dissolved organic carbon concentration and positively related to the mean depth of the lakes. The results emphasize the need for measurements of CO2 exchange at ice-melt to accurately quantify CO2 evasion from Arctic lakes.

Automated summary

The current estimates of CO2 evasion from Arctic lakes are highly uncertain due to the lack of studies that integrate seasonal variability, particularly during the spring ice-melt period. This study quantified the annual CO2 evasion in 14 clear-water Arctic lakes in Northern Sweden using mass balance and high-frequency loggers. The findings highlight the significance of measuring CO2 exchange during ice-melt for accurately estimating CO2 evasion from Arctic lakes.