典型冰冻圈区域河流黑碳研究进展

Research progress of riverine black carbon in typical cryospheric regions

冰冻圈区域河流是连接冰冻圈及河流中下游,乃至海洋碳库的重要通道。气候变暖导致冰冻圈快速萎缩,致使储存在冰川和冻土中的黑碳暴露并迁移,深刻影响冰冻圈区域河流黑碳的来源及输移过程,对海陆碳循环具有重要意义。本文重点综述了青藏高原、北极、阿尔卑斯山脉、落基山脉以及安第斯山脉等典型冰冻圈区域河流黑碳的通量、来源以及传输运移途径。结果表明:典型冰冻圈区域河流黑碳的传输通量约为2.29 Tg·a^(-1),约占全球河流黑碳通量的5.33%。除大气干湿沉降和径流侵蚀外,冰川消融和冻土退化对冰冻圈区域河流黑碳浓度及通量变化具有显著影响,其中青藏高原和阿拉斯加冰川消融每年释放进入河流的黑碳通量分别为10.00 Gg(7.74~12.30 Gg)和0.60 Gg(0.47~0.73 Gg)。然而,冻土退化对冰冻圈区域河流黑碳的影响程度尚不清楚。总体而言,冰冻圈区域河流黑碳的研究不足将严重限制区域乃至全球碳循环的系统认识,未来亟需加强冰冻圈区域河流黑碳的系统监测与研究,为量化全球变暖背景下冰冻圈区域河流黑碳变化及其影响提供科学数据。

Cryospheric rivers play a critical role in linking the cryosphere region,middle&downstream regions of the river,and even the oceanic carbon pool.Studying of source,migration,and transformation of the riverine black carbon(BC)in the cryosphere region will improve understanding of the marine and terrestrial carbon cycle.Climate warming has caused rapid cryospheric shrinkage recently,resulting in stored BC released due to glacier melting and permafrost thawing,which profoundly affects BC concentrations in the river source regions.This paper reviews the research progress of riverine BC in typical cryosphere regions,including the Arctic,Tibetan Plateau,Alps,Rocky Mountains and Andes Mountains.The results show that the fluxes of riverine BC in the global cryosphere region are about 2.29 Tg·a^(-1),accounting for 5.33% of the global riverine BC flux.In addition to atmospheric dry&wet deposition and runoff erosion,glacier melting and permafrost thawing significantly influence the concentration and flux of riverine BC.The annual fluxes of BC released by glacier meltwater in the Tibetan Plateau and Alaska are about 10.00 Gg(7.74~12.30 Gg)and 0.60 Gg(0.47~0.73 Gg),respectively.However,the effect of permafrost thawing on BC in cryospheric rivers remains unclear.The lack of research on BC in cryospheric rivers will seriously limit the systematic understanding of regional and even global carbon cycles.In the future,it is necessary to continue to strengthen the systematic monitoring and research on BC in cryospheric rivers,which provide scientific data for quantifying the change and impact of riverine BC in the cryosphere region under climate warming.