Analysis of the daily 222Rn courses in the surface layer of the atmosphere

By the continual monitoring we obtained extensive set of data about Rn-222 activity concentration in the surface layer of the atmosphere in Bratislava. The annual courses of the Rn-222 activity concentration present the annual variations with the maximum values in the autumn months and minimum values in the spring. The average daily courses of the Rn-222 activity concentration for individual months have a form of waves with a maximum in the morning hours and with the minimum in the afternoon. The maximal amplitudes of the daily waves were found out in the summer months. By Fourier's analysis of the average daily radon waves according to equation (1), the nature of amplitudes A1, A2 and phases Φ1, Φ2 were found out for various months. the expressions of these parameters were appeared in the form of the relations (2), (6), (7), and (8). These relations enable to calculate amplitudes and phases of the daily radon waves for various localities. We can also determine time on the base of Eq.(l), when the average daily Rn-222 activity concentration will be determine by a short-period measurement. The average daily radon waves can be then restored according to Eq. (1), for example with the aim to calculate the effective dose from radon, or with an intention to evaluate the intensity of the vertical mixing in the atmosphere. (author)