摘要
为了研究雪冰中不溶性有机碳(Water-insoluble Organic Carbon,WISOC)的含量及其辐射强迫作用,于2012年7月和8月对青藏高原南部纳木错流域扎当冰川90个表层雪冰样品中WISOC的含量进行了分析,采样期间利用地物光谱仪实地测量了反照率.结果表明,在消融季节(7—8月),扎当冰川表面被裸冰、老雪和新雪覆盖,以上3种消融情形下WISOC的平均含量分别为(1618.4±1236.0)、(432.3±329.7)和(183.7±158.0)ng·g-1,雪冰的融化导致WISOC等吸光性物质在冰川表面的富集,降低了冰川表面反照率.通过SNICAR模型(Snow,Ice,and Aerosol Radiative Modle)敏感性分析表明,3种情形下WISOC降低雪冰表面反照率(贡献率)分别为0.0020(6.8%)、0.0018(7.4%)和0.0010(2.1%),对应的WISOC的辐射强迫分别为1.14、1.34和0.81 W·m-2.平均地,WISOC对辐射强迫的影响超过了黑碳(BC)影响的20%,而在新雪覆盖条件下,WISOC对辐射强迫的影响甚至达到了粉尘影响的72.3%.因此,虽然雪冰中的WISOC的吸光能力相对于BC较弱,但所引起的雪冰表面反照率降低及冰川消融等效应不容忽视.
In order to analyze the concentration of water-insoluble organic carbon（ WISOC） in snow / ice and its effect on the radiative forcing,a total of90 surface snow / ice samples from Zhadang glacier in the southern Tibetan Plateau were collected during the summer of 2012. Concentration of WISOC was analyzed using a thermal-optical method and albedo was measured using Analytical Spectral Devices（ ASD） spectrometer. During melting season,theglacier surface is usually covered by bare ice,aged and fresh snow. Average WISOC concentrations were（ 1618. 4 ± 1236. 0）,（ 432. 3 ± 329. 7） and（ 183.7±158.0） ng·g^-1 in three melting cases respectively. The melting of glacier resulted in the enrichment of WISOC and other light absorbing particles,thus reducing the snow / ice surface albedo. Sensitivity analysis using SNICAR model showed that the albedo reduction（ contributions） caused by WISOC were 0.0020（ 6.8%）,0.0018（ 7.4%） and 0.0010（ 2.1%）,respectively. The radiative forcing exerted by WISOC was found to be 1.14,1.34 and 0.81W·m^-2 respectively for three cases. On average,albedo reduction caused by WISOC was over 20% of that by black carbon,especially when the surface was covered by fresh snow. The influence of WISOC on the radiative forcing was even up to 72.3% of that by dust effect. Although the absorption ability of WISOC was weaker than BC,it cannot be ignored that WISOC would cause snow / ice surface albedo reduction and glaciers melting. Therefore,this study will gain a better understanding of the optical absorption material in the glaciers and water resources on the Tibetan Plateau.
出处
《环境科学学报》
CAS
CSCD
北大核心
2016年第3期802-811,共10页
Acta Scientiae Circumstantiae
基金
中国科学院重点部署项目(No.KJZD-EW-G03-04)
国家杰出青年科学基金项目(No.41225002)
国家重大科学研究计划(No.2013CBA01801)~~
关键词
不溶性有机碳
反照率
辐射强迫
扎当冰川
青藏高原
water-insoluble organic carbon
albedo
radiative forcing
Zhadang glaciers
Tibetan Plateau
