open access

https://hdl.handle.net/2115/49054

Snow chemistry in the seasonal snow region

日本語

microbiological activity

2012-03-31

Institute of Low Temperature Science, Hokkaido University

Low Temperature Science

70

119-129

The snow particle is an indicator of atmospheric environmental information. The ratio of Cl-/Na+ concentration in the snow sample at Sapporo and Tohkamachi is nearly equal to that in the sea water. This result suggests that the origin of Na+ and Cl- in the snow particle is sea water. A good relation is observed between Na+ concentration of the snow and the heights of a convective mixing layer of cloud. It can be seen that Na+ concentration of the snow increased in proportion to the height of the convective mixing layer. The synoptic weather conditions affect chemical properties of snow particle. Sea salt materials are dominated in the snow formed under the winter monsoon pressure pattern. On the other hand, non sea salt materials are dominated in the snow formed by a low pressure system on the Sea of Japan or on the Pacific Ocean. A close relationship is observed between temperature at the cloud top and the oxygen isotopic composition of snow, and the mutual relationships are recognized for each weather condition. Winter precipitation formed during the winter monsoon has a higher value of oxygen isotopic composition than those formed when a cyclone is positioned over the Pacific Ocean near Honshu at the same temperature. If there is no meltwater runoff in the snowpack resulting from surface melting, then chemical substances in the snowpack will be retained in each snow layer. The concentrations of chemical substances increase and the pH value decreases in the meltwater. Concentration of chlorophyl-a in the snowpack is higher at the coniferous forest site than at both the open site and the deciduous forest site. Activity of snow algae is considered to be large during the snowmelt season.

紀要論文

Version of Record

1880-7593