Cao Yang, Wang Min, Zhang Fei, Hu Yadan, Yang Liu, Wang Yongtao, Wu Di, Jin Zhangdong
SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, China; College of Resources and environment, Hubei University, Hubei 430062, China.
College of Resources and environment, Hubei University, Hubei 430062, China.
Sci Total Environ. 2023 Nov 25;901:165842. doi: 10.1016/j.scitotenv.2023.165842. Epub 2023 Jul 27.
Over geological time scales, continental silicate weathering is considered as a critical carbon sink that regulates long-term climate feedback. By contrast, recent studies indicate that sulfide oxidation during weathering can be as a potential carbon source. However, whether chemical weathering in glacial conditions characterized by extreme erosion is a net carbon sink or source remains elusive. Here, we present the seasonal carbon cycle processes in a typical glacier catchment, via high-resolution (weekly) river water sampling during the whole 2017 in the Laohugou river, northeastern Tibetan Plateau. Our seasonal result shows that the release of CO by sulfide oxidation during the monsoon period can be much faster than CO consumption through weathering of silicate rocks, with maximum of ∼26 times. Extending to global glacial basins, we observed a consistent pattern that inorganic carbon releases in alpine glaciers are faster than atmospheric CO consumption. We propose that weathering in global glacial environment acts as a significant carbon source, and thus affects climate feedback.
在地质时间尺度上，大陆硅酸盐风化被视为调节长期气候反馈的关键碳汇。相比之下，近期研究表明，风化过程中的硫化物氧化可能是潜在的碳源。然而，在以极端侵蚀为特征的冰川条件下，化学风化是净碳汇还是碳源仍不清楚。在此，我们通过对青藏高原东北部老虎沟河2017年全年进行高分辨率（每周一次）河水采样，展示了典型冰川集水区的季节性碳循环过程。我们的季节性结果表明，季风期硫化物氧化释放CO的速度可比硅酸盐岩石风化消耗CO的速度快得多，最高可达约26倍。扩展到全球冰川流域，我们观察到一个一致的模式，即高山冰川中无机碳的释放速度快于大气中CO的消耗速度。我们提出，全球冰川环境中的风化作用是一个重要的碳源，从而影响气候反馈。
