JACOBI AND ANDRE 3804 1 <== wee ee e ee SSN TT 0st E ws: n NNN 27/28. 8.56 22-3h 0,6 + Ts — WNN Ey ~~ Nw O4jCc [am 0,2 = 0 > —— JWN 20. 5. 56 Radon -Profile —— exp. (MOSES et al, 1960) 20h 122 56 ---calculated 3! ‘ . 30 40 0-4h 6 © Cc —_ 5L Temperature - Profile 4-L — = 3b Nol Ee —~ NN th =, 0 , 1 5 30 Altitude z(m) Fig. 3. , 50 Comparison of observed and calculated Rn profiles near ground level under inversion conditions. theoretical results. Figure 4 shows two relative Rn™ profiles which were observed by Wezler et al. [1955] during twoApehts over Ohio. They are compared with Rn™ profiles which were caleulated with equal exhalation rate from the K profiles WNN, NNN, and SSN (see Figures 1 and 2); the Rn™ profile NNN was standardized to a concentration of 15 epm/g at 2- km altitude. The profile observed on the first flight (Oct. 25, 1951) agrees rather well with the theoretical vertical distribution for the turbu- lence case WNN. The slope of the profile from the following day corresponds in the lower troposphere to the calculated Rn*™ profile for strong turbulence (case SSN) but approaches the profile for the NNN case (normal turbuler.ce) in the upper troposphere. The mean profile of both flights agrees rather well with the caleulated profile NNN for which the Rn™ concentration at an altitude of 2 km is about one-half the concentration near ground level. This is also consistent with observations of Wigand and Wenk [1928] and Wilkening [1953]. This comparison indicates that it is possible to derive the vertical profile of the turbulent diffusion coefficient from measurements of the relative vertical Rn™ distribution. The available measurements within the troposphere give some confidence that the K profile NNN, given in Figure 1, indeed represents average turbulence