Concentration and δD of molecular hydrogen in boreal forests:: Ecosystem-scale systematics of atmospheric H2 -: art. no. 1888

[1] We examined the concentration and deltaD of atmospheric H-2 in a boreal forest in interior Alaska to investigate the systematics of high latitude soil uptake at ecosystem scale. Samples collected during nighttime inversions exhibited vigorous H-2 uptake, with concentration negatively correlated with the concentration of CO2 (-0.8 to -1.2 ppb H-2 per ppm CO2) and negatively correlated with deltaD of H-2. We derived H-2 deposition rates of between 2 to 12 nmol m(-2) s(-1). These rates are comparable to those observed in lower latitude ecosystems. We also derive an average fractionation factor, alpha = D:H-residual /D:H-consumed = 0.94 +/- 0.01 and suggestive evidence that a depends on forest maturity. Our results show that high northern latitude soils are a significant sink of molecular hydrogen indicating that the record of atmospheric H-2 may be sensitive to changes in climate and land use.