sup 222Rn, (sup 222)Rn progeny and (sup 220)Rn progeny as atmospheric tracers of air masses at the Mauno Loa Observatory.

摘要

(sup 222)Rn, (sup 222)Rn progeny and (sup 220)Rn progeny concentrations in air were measured at the Mauna Loa Observatory (MLO) in Hawaii during March 1989 in order to investigate the feasibility of using them as atmospheric tracers to help determine local air mass flow patterns. Charcoal traps, cooled to dry ice temperatures, were used to collect (sup 222)Rn, which was subsequently measured in pulse ionization chambers at the Environmental Measurements Laboratory (EML). (sup 222)Rn progeny and (sup 220)Rn progeny for 37 samples were measured at the Observatory by sampling high volumes of air through filters, which were counted for up to 11 h in alpha scintillation counters. Individual progeny concentrations were calculated using both least squares and maximum likelihood techniques. In general, (sup 222)Rn progeny and (sup 220)Rn progeny concentrations were low when free tropospheric air was present (downslope and tradewind conditions), and consistently higher when surface air from the island broke through the trade wind inversion layer (upslope conditions). The data suggest that (sup 222)Rn, (sup 222)Rn progeny, or (sup 220)Rn progeny monitoring may provide new and useful information to help indicate the different air flow patterns present at MLO. 17 refs., 5 figs., 2 tabs.