Release of Carbon Dioxide from Frozen Soil to the Arctic Atmosphere

Abstract

DELINEATION of sources and sinks of CO₂ is fundamental to understanding carbon cycling in an Arctic ecosystem. Kelley et al.¹ observed a large, variable increase in CO₂ concentration at the tundra surface over ambient air CO₂ beginning a few days after the first snowfall. This increase continued into December, at which time CO₂ declined to relatively stable concentrations approaching ambient air levels. CO₂ at the surface increased from early May to late June until the snow disappeared. Bashenina² also observed CO₂ concentrations under the snow higher than atmospheric values. The present investigation was undertaken to explain the source of the subnivean CO₂.