Hydrogen soil deposition in northern boreal zone

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 twodimensional model results were in the range of 0.18-0.52mm 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 0.06-0.52mm s -1 excluding the wetland site which had negligibly small v d due to water saturation.