Argon-37 as a measure of atmospheric vertical mixing

Cosmogenic argon-37 distribution in the atmosphere is determined by its production, decay, and by atmospheric transport. If the first two processes are known, one may use the observed distribution of argon-37 to determine global scale atmospheric transport. The atmospheric transport, as a first approximation, assumes that the flux of argon-37 lies in the direction of its gradient of concentration. The proportionality factor, called the eddy diffusion coefficient, is related to atmospheric turbulence. Using estimates of cosmic ray production of argon-37 given by Rama in Lal and Peters and observations of minimum concentrations (to minimize the likelihood of man-made contamination) given by Oeschger and Loosli, it will be shown that the likely global vertical diffusion coefficient averages about 5 x 104 cm2 sec-1