摘要
积雪作为大气固态降水过程的主要形式,是反映大气化学成分的良好媒介。然而,积雪样品在采集后的不同储存和处理方式可能会影响其原始信息的获取。本研究采集青藏高原腹地纳木错地区的积雪样品,使用不同前处理方法探究其对主要阳离子浓度的影响。结果表明:积雪样品融化后第3天及更长时间,使用不过滤的前处理方式会使测试结果明显偏离实际值。过滤操作能规避碳酸盐矿物溶解对Ca2+、Mg2+和Sr2+的富集,减少对大陆粉尘来源贡献的高估;对K+和Na+的影响则主要通过黏土矿物与水体间的离子交换实现,使得前者浓度降低、后者升高,从而可能低估生物质燃烧源的贡献、高估海盐输入。就不同孔径的滤膜而言,0.20μm滤膜过滤效果优于0.45μm滤膜。过滤后溶液的大部分离子在冷藏或常温存储的前10天变化较小(<10%)。综上,本文建议积雪样品在融化后当天使用孔径为0.20μm的滤膜过滤,滤后溶液存储方式可选择冷藏或常温保存,并在10天或更短时间内完成测试。
Snow is the main form of atmospheric solid precipitation,and is a good medium to reflect the chemi⁃cal composition of the atmosphere.However,different ways of treatment and storage for snow samples after col⁃lection may influence the measurement of the original information they reserved.The impacts of different filtra⁃tion treatments,storage time,and storage temperature(i.e.,room temperature~25℃,cold~4℃,and freez⁃ing~-18°C)on the cationic concentrations of snow collected from the Nam Co basin,central Tibetan Plateau,were explored in this study.The results show that the non-filtration treatment will make the cationic concentra⁃tions significantly deviate from their initial values after the third day of storage.The filtration treatment could ef⁃ficiently avoid the enrichment of Ca2+,Mg2+,and Sr2+by decreasing carbonate mineral dissolution.Hence,filtra⁃tion could reduce the overestimation of the contribution from continental dust.Nevertheless,the alteration of K+and Na+concentration is mainly governed by the ion exchange between clay particles and solution.This process will decrease the concentration of K+but increase Na+.Thus non-filtration treatment may underestimate the con⁃tribution of biomass burning but overestimate the inputs from marine salt dissolution.As for filter membranes with different pore sizes,the filtration effect of 0.20μm membrane is better than 0.45μm membrane.Most of the ion concentrations in the filtered liquid have displayed a slight change in the first ten days of cold or room temperature storage(less than 10%).To sum up,it is recommended that snow samples should be filtered on the day after melting and using an aperture of 0.20μm membrane to filter the solution according to our research.Be⁃sides,the filtered fluid can be cold storage in a fridge or at room temperature for the measurement of cations.In the end,the test for cationic concentration should be finished within 10 days or less after the filtration.
作者
刘晓明
于正良
邬光剑
杨一博
叶程程
高少鹏
黄菊
LIU Xiaoming;YU Zhengliang;WU Guangjian;YANG Yibo;YE Chengcheng;GAO Shaopeng;HUANG Ju(State Key Laboratory of Tibetan Plateau Earth System,Resources and Environment(TPESRE),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;School of Environmental and Geographical Sciences,Shanghai Normal University,Shanghai 200234,China)
出处
《冰川冻土》
CSCD
北大核心
2023年第3期1142-1154,共13页
Journal of Glaciology and Geocryology
基金
国家杰出青年科学基金项目(41725001)
自然资源部/广西岩溶动力学重点实验室开放课题(KDL&Guangxi202006)资助。
关键词
青藏高原
积雪
阳离子浓度
储存方式
储存时间
Tibetan Plateau
snow
cationic concentration
storage condition
storage time
