2004 Volume 10 Issue 1 Pages 41-48
In order to collect both rain and snow samples with a single collector, heating apparatuses were installed to two types of conventional precipitation collectors utilized in Japan :(1) Wet-only collector equipped with a sliding roof to collect wet and dry depositions separately, (2)Bulk 1 collector composed of a funnel, a filtration unit and a bottle. The heating apparatuses were equipped to both the collection funnel unit and the glass-made filtrating unit of the collectors so that the units were kept at 5±1°C for melting snow on the funnel and minimizing the possible evaporation. In addition, (3)Bulk 2 collector, which was particularly designed for collecting snow by a cylindrical bag, was examined on its performances. Collection efficiencies of precipitation of these three collectors were compared with an authentic rain gauge. Major ion concentrations were compared among the samplers. Collection efficiencies of precipitation of these collectors showed remarkable agreements with the authentic rain gauge. The concentrations of major ions of samples collected with Bulk 1 and Bulk 2 collectors showed slight differences with Wet-only collector: Bulk 1 yielded higher concentration of calcium ion and Bulk 2 showed higher levels in ammonium, sulfate, nitrate, calcium, and potassium ions. These differences, however, are not surprising because depositions of gaseous and particulate species onto the collection funnel during the dry period from the atmosphere would be intrinsic for the bulk collectors. The heating apparatus did not affect the chemical congruity of the precipitation samples in spite of the above differences. The collectors with heating apparatus would be free from the potential bias associated with alternating a conventional rain collector and a bulk-type snow collector before and after the snow months.