Bulletin of Glaciological Research ,0 (,**2) +/ῌ,+ῌJapanese Society of Snow and Ice

15

Chemical Characteristics of Snowpack due to Di#erences in Snowfall Type in Japan
AlpsTakayuki KURAMOTO+, Shailendra Kumar SHAH+, Motoki TANAKA, and Keisuke SUZUKI+, ,+ Department of Environmental Sciences, Faculty of Science, Shinshu University, Asahi, Matsumoto -3*ῌ20,+, Japan, Institute of Mountain Science, Shinshu University, Asahi, Matsumoto -3*ῌ20,+, Japan(Received February +/, ,**2; Revised manuscript accepted May ,1, ,**2)

AbstractWe conducted a snow survey in February ,**0 and January ,**1 in Japan Alps. Approximately*.0* m and +.*/ m snowfalls were deposited at the study site in February ,**0 and January ,**1,respectively. It was observed that the occurrence of snowfall was due to the low pressure formationin the vicinity of Japan and it also being the winter monsoon period. As a result of the analyzed
snowpack, including new snow at a high resolution every *.*- m, a plurality of high-electric conductivity layers were observed at di#erent depths. From the measurement of the major ion concentrations, it was observed that the high-electric conductivity layers had di#erent chemical characteristics.
High concentrations of NO-῍ and SO.,῍ deposits were observed in the snowpack layer that was formed
due to the low-pressure system that passed in the vicinity of Japan. On the other hand, the layer thatformed during the winter monsoon pattern, large amounts of sea salts were deposited in the snowpack
in January ,**1. However, layers with a high sea-salt concentration were not observed in February,**0. We analyzed the movement of the air mass that ﬂowed into the study area. Air mass passed
through the city at the time of the passage of the low-pressure system. In addition, the air mass thatcrossed the Sea of Japan entered the study area during the winter monsoon pattern. However, themovement of the air mass was di#erent during the winter monsoon pattern in February ,**0 andJanuary ,**1.

+.

Introduction

The chemical components accumulated with snowfall during the winter season are stored in the snowpack. The accumulated chemical components areseparated by the process when the snow particle metamorphoses into the surface of the snow particle andbegins to ﬂow out with the snowmelt water (Suzuki,+330; Suzuki, ,***). The snowmelt water ﬂow in theearly snowmelt period begins to dissolve the chemicalcomponents at the surface of the snow particle. Therefore, many chemical components are included in thesnowmelt water that begins to ﬂow out in this period.
The acidiﬁcation occurs temporarily in the river as
the snowmelt water ﬂows out (Kuramoto and Suzuki,,**0).
A study on the weather conditions and winterprecipitation was performed. Suzuki (+32-, +32.) collected the winter precipitation and snowpack of one
winter season in Sapporo, Hokkaido prefecture. Theorigin of the chemical components was examined inthe sample. SO.,῍ was inﬂuenced by the use of fossil
fuels in Sapporo, whereas Naῌ and Cl῍ were sea salt.

Suzuki and Endo (+33.a, +33.b) collected winter precipitation samples everyday in Tohkamachi, Niigata
prefecture. The chemical characteristics of the samples and the weather conditions were investigated.
Large amounts of sea salt were deposited during thewinter monsoon pattern and large amounts of acidcontaining materials were deposited when a lowpressure system passed the south coast of Japan.
There is no outbreak source near the mountainous regions. The pollutants from the neighborhood
are not deposited in these regions. In addition, theweather condition changes with time. Therefore, sampling at short intervals of time is necessary to examine a detailed change. However, if the area does notpass through the snowmelt process, it is thought thatthe chemicals originating from the precipitation isstored and accumulated intermittently. The chemical components preserved in the snowpack of themountainous region can be obtained through various
atmospheric information. However, it is di$cult toclarify the exact time scale of the deposited snow ineach layer where there is little availability of meteorological observation data in the mountainous region.
Therefore, the presumption of the deposition period