Influence of turbulence and uniform currents on the vertical distribution of Na-24 and Cl-39 radioisotope concentrations

An attempt is made to evaluate the influence of the turbulence and vertical uniform flows of air on the concentration distribution of the short-lived cosmogenic radioisotopes Na-24 and Cl-39 in the vertical air column of atmosphere at the height of 0-50 km. The continuity equation, in which the velocity and turbulent diffusion are taken into account, is used for calculations. The analysis of the calculation results shows that the totality of the uniform flows of air and turbulence has greater influence on the redistribution of Na-24 concentration than that of Cl-39. This difference is supposed to be resulted first of all from the inequality of the restoring time of equilibrium distribution of these radioisotopes. The calculations performed confirm the efficiency of the influence of the vertical air currents. The turbulence acts only as the equalizing factor. The increase of the turbulence coefficient in case of Na-24 and Cl-30 in the upper and lower layers leads to the increase and in the maximum production level to the decrease of the quantity of these admixtures in the atmospheric layer under study (0-50 km)