Hydrodynamic sorting-induced overestimation of permafrost carbon degradation across the East Siberian Arctic shelf

Quantitatively understanding the fate of terrestrial organic carbon (terrOC) on continental shelves is critical for advancing predictive models of the global carbon cycle. This holds particular significance in the Arctic, where rapid permafrost thaw mobilizes ancient terrOC—a reservoir storing twice the atmospheric carbon—into Arctic shelves at ~45.6 Tg yr⁻¹, with implications for amplifying warming through carbon-climate feedbacks. However, the dual controls of biodegradation and hydrodynamic physical sorting create nonlinear terrOC gradients across the shelf, posing challenges for assessing terrOC remineralization efficiency‌. Our work aims to clarify the roles of biodegradation and hydrodynamic sorting in modulating terrOC fate on the East Siberian Arctic Shelf (ESAS). We employ molecular dynamics simulations and polarity/reactivity continuum analysis to characterize how these processes collectively influence terrOC remineralization and reburial across the shelf. This dataset includes: analysis results of polarities and reactivities of terrestrial organic molecules based on DFT calculations; a ‌high-resolution geospatial dataset‌ of collected terrOC content and biomarker concentrations across the ESAS.

定量解析陆架区域陆地有机碳（terrestrial organic carbon, terrOC）的归宿，对于完善全球碳循环预测模型至关重要。这一点在北极区域尤为关键：快速升温引发的多年冻土解冻，将储碳量达大气碳库两倍的古老陆地有机碳以约45.6太克每年（Tg yr⁻¹）的速率迁移至北极陆架，可能通过碳-气候正反馈加剧全球变暖。然而，生物降解与水动力物理分选这双重调控机制，会在陆架区域形成非线性的陆地有机碳梯度，给评估陆地有机碳的再矿化效率带来了挑战。本研究旨在厘清生物降解与水动力分选过程，如何调控东西伯利亚北极陆架（East Siberian Arctic Shelf, ESAS）上陆地有机碳的归宿。我们采用分子动力学模拟与极性/反应性连续谱分析方法，解析这两类过程如何共同影响陆架区域陆地有机碳的再矿化与再埋藏过程。本数据集包含两部分内容：一是基于密度泛函理论（Density Functional Theory, DFT）计算得到的陆地有机分子极性与反应性分析结果；二是覆盖东西伯利亚北极陆架的、经实地采集得到的陆地有机碳含量与生物标志物浓度的高分辨率地理空间数据集。