Xiaole Sun , Carl-Magnus Mörth , Don Porcelli , Christoph Humborg , Liselott Kutscher , Catherine Hirst , Melissa J. Murphy , Trofim Maximov , Roman E. Petrov , Per S. Andersson
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引用次数: 0
Abstract
Permafrost degradation has led to increased riverine ion concentrations and export to the sea. This study uses major ion data collected in summer in 2012 and 2013 and during spring flood in 2015 to investigate the spatio-temporal variability in chemical weathering patterns and the associated CO2 consumptions in one of the major Arctic Rivers – the Lena River and its tributaries. The catchment shows strong spatial variations in major ion concentrations in the main river and tributaries. The weathering flux represented by TIS (total inorganic solids) is calculated to be 112 Tg/yr, which is almost double that calculated in an earlier study 20 years ago for the same region. The CO2 consumption is estimated to be 4.9 Tg C/yr, which is approximately equally shared between weathering of carbonates and silicates, despite two thirds of TIS derived from carbonates and the rest of TIS by silicates and evaporites. Our results suggest an enhanced role for silicate weathering in elemental export and CO2 drawdown due to the ongoing transition from a near surface-dominated system towards a deep groundwater dominated system caused by permafrost degradation in the Arctic region under a warmer climate. Such an enhanced weathering pattern is also expected in other Arctic rivers; hence, a re-evaluation of the weathering budgets is clearly needed. Our findings improve our understanding of the response of the weathering regime in large Arctic river catchments to ongoing climate-driven permafrost loss, which also sheds lights into the role of land-sea element fluxes in sustaining primary production and carbon cycling on the Arctic shelf seas.
期刊介绍:
Chemical Geology is an international journal that publishes original research papers on isotopic and elemental geochemistry, geochronology and cosmochemistry.
The Journal focuses on chemical processes in igneous, metamorphic, and sedimentary petrology, low- and high-temperature aqueous solutions, biogeochemistry, the environment and cosmochemistry.
Papers that are field, experimentally, or computationally based are appropriate if they are of broad international interest. The Journal generally does not publish papers that are primarily of regional or local interest, or which are primarily focused on remediation and applied geochemistry.
The Journal also welcomes innovative papers dealing with significant analytical advances that are of wide interest in the community and extend significantly beyond the scope of what would be included in the methods section of a standard research paper.