Deposition
velocities ( v _d) of molecular hydrogen were measured in the
northern boreal zone in Pallas. Three separate methods were used to estimate the
soil uptake rate. For soil chamber measurements, three sites (forest, wetland
and above tree line) were selected according to different soil properties. The
deposition velocity was calculated with radon tracer method taking advantage of
nocturnal radon build-up and hydrogen decrease in the shallow mixing layer above
ground. A two dimensional model was used to estimate corresponding night time
values for v _d and radon exhalation rate. The radon tracer and
two-dimensional model results were in the range of 0.18–0.52 mm s^–1.
All results were obtained for unfrozen soils, and there was no clear temperature
dependence related to v _d. Soil chamber results were in the
range of 0.06–0.52 mm s^–1 excluding the wetland site which had
negligibly small v _d due to water
saturation.