Concentration Changes of Acidic Ions in Winter Precipitation in Tohkamachi, Japan
Concentration Changes of Acidic Ions in Winter Precipitation in Tohkamachi, Japan
复制标题
日本十町冬季降水酸性离子浓度变化
DOI：
10.5190/tga.46.161
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Y. Endo
中科院分区：
文献类型：
--
作者：
Keisuke Suzuki;Y. Endo
在竹内市进行了冬季降水的化学研究。研究了冬季降水化学性质与气象条件的关系，采集了东北地区1990年12月24日~1991年4月9日、1991年12月17日~1992年4月10日和1992年12月15日~1993年4月10日的逐日降水样本，对样本进行过滤，用电导率仪和pH计分别测定了电导率和pH值。用离子色谱仪(Dionex 2020 I/SP)测定了冬季降水中的阴离子和阳离子。所有冬季降水样品中的Cl-/Na+和Mg2+/Na+的比值与海水中的接近。这一结果表明，冬季降水中Na~+、Mg~(2+)和Cl~-的来源为海水。冬季降水中NO_3~-和NH_4~+的来源被认为是非海盐。SO_4~(2-)和Ca~(2+)的来源既有海水又有非海盐。NO3-和nssSO42-是冬季降水的酸性物质，pH值下降。NH4+和nss Ca~(2+)是酸沉降的中和物质，1991年冬季、1992年冬季和1993年冬季降水的加权平均pH值分别为4.46、4.16和4.22。所有样品的pH值均小于5.2。Tohkamachi的冬季降水呈酸性，且冬季降水的pH比固体降水的pH更酸性。天气条件影响冬季降水的化学性质。在冬季季风压力模式下形成的降水中，海盐物质占主导地位。另一方面，日本海或太平洋上的低压系统形成的降水中，非海盐物质占主导地位。降水中酸性物质的比例越大，表明太平洋低压系统形成的降水的酸性越强。
Chemical studies of the winter precipitation were conducted in Tohkamachi city. The relationships between the chemical property of winter precipitation and the weather condition were studied.Samples of daily precipitation were collected in Tohkamachi during winter periods from December 24, 1990 to April 9, 1991, from December 17, 1991 to April 10, 1992 and from December 15, 1992 to April 10, 1993.The samples were filtered, and conductivity and pH were measured with a conductivity meter and pH meter, respectively. Anions and cations were determined by an ion chromatography (Dionex 2020 i/SP).The ratios of Cl-/Na+ and Mg2+/Na+ in all samples of winter precipitation are nearly equal to those in the sea water. This result suggests that the origin of Na+, Mg2+ and Cl- in the winter precipitation is sea water. The origin of NO3- and NH4+ in the winter precipitation is considered to be non sea salt. The origins of SO42- and Ca2+ are both sea water and non sea salt. NO3- and nssSO42- are the acidic materials and decline pH value of the winter precipitation. NH4+ and nssCa2+ are the neutralization materials of acid precipitation.Weighted average pH of precipitation is 4.46 for 1991 winter, 4.16 for 1992 winter and 4.22 for 1993 winter. pH values of all samples are less than 5.2. winter precipitation in Tohkamachi shows acidity, and pH of winter rain shows more acidic than that of solid precipitation.The synoptic weather conditions affect chemical properties of winter precipitation. Sea salt materials are dominated in the precipitation formed under the winter monsoon pressure pattern. On the other hand, non sea salt materials are dominated in precipitation formed by a low pressure systems on the Sea of Japan or on the Pacific Ocean. The larger ratio of acidic materials in precipitation indicates the stronger acidity of precipitation formed by a low pressure systems on the Pacific Ocean.