Kinetic assessment of gas exchange between the soil and the atmosphere by the static chamber method

The method of closed (static) chambers finds wide use in the study of gas and vapor flows at the soil-atmosphere interface. However, it can significantly underestimate the values under study in some cases, depending on the procedure of flux calculation from the experimental data on the dynamics of gas and vapor concentrations in a closed chamber. An original calculation procedure suitable for different (linear and nonlinear) trends in the dynamics of concentrations is proposed. It is based on the tangent equation to the trend line at the starting point of the experiment (t = 0). The comparison with the conventional procedure shows that the difference can be from several units to tens of times. The theory of the static chamber method and possible latent reasons for underestimation of gas exchange at the soil-atmosphere interface by this method are discussed.