First year-round record of Antarctic Dry Valley soil CO2 flux

•Using an FD Chamber, we collected the first annual record of Antarctic Dry Valley soil CO2 flux.•Two sources of soil gas flux were inferred, one microbial, and the other of crustal origin.•Wind-induced pumping was an important mechanism of soil gas transport to the free atmosphere.

The McMurdo Dry Valleys of Antarctica are home to unique soil microbial communities. Using a specially designed Forced Diffusion flux chamber, we logged the first year-round record of soil surface CO2 flux in Hidden Valley. We observed low but positive fluxes during two sustained events, and conclude that the observed variability was clearly driven by both biotic and abiotic factors.