北极阿拉斯加巴罗地区夏季降水化学特征

CHEMICAL CHARACTERISTICS OF SUMMER PRECIPITATION AT POINT BARROW,ARCTIC ALASKA

本文根据１９９４年８～９月份阿拉斯加北坡巴罗地区降水的实测资料，初步探讨了本区夏季降水的化学特征及环境意义。结果表明：巴罗地区夏季降水的ｐＨ值比冬季高，平均值接近与大气ＣＯ２平衡时纯水的酸度状况；电导率值普遍较低，个别电导率值较高的样品可能与海盐粒子有关；样品的主要离子浓度与北极其它地区和青藏高原的降水化学成分相当，ｅｘＳＯ４２－基本接近于零，反映了受人类活动影响非常小的自然本底状况。研究认为巴罗地区是进行北极地区现代环境状况研究的理想地区之一。

Over 20 precipitation samples at Point Barrow,Alaska in Aug. and Sep. of 1994 was analysised.The pH value is between 4.76-6.26,of which higher in summer than in winter.The electic conductivities in precipitation is rather low,varing between 4.9-102.0 μS/cm,and the abnormal high values are concerned with the sea salt.The chemical composition of precipitation at Point Barrow,Alaska have equal level to that at the other Arctic regions and on the Qinghai Xizang Plateau.The extremely low value of exSO 2- 4 indicates that the anthropogenic effect on this region is small.Point Barrow is one of the most suitable places for studying the Arctic environment conditions.