Khadim Fahad K, Getirana Augusto, Bindlish Rajat, Kumar Biswas Nishan, Nie Wanshu, Lahmers Timothy M, Kumar Sujay V
Hydrological Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD 20771.
Science Applications International Corporation, McLean, VA 22102.
Proc Natl Acad Sci U S A. 2024 Dec 3;121(49):e2412551121. doi: 10.1073/pnas.2412551121. Epub 2024 Nov 25.
Sea surface salinity ([Formula: see text]) is a key parameter in the thermohaline circulation of global oceans. Near the megadeltas, inland streamflow through large catchments plays a crucial role in mediating salinity. While some regional studies have investigated how [Formula: see text] is impacted through water cycle and climate components, a global scale quantification of inland streamflow contribution on [Formula: see text] variability is lacking. Here, we utilized remote sensing and observation-driven datasets to quantify the statistical associations between [Formula: see text] and streamflow ([Formula: see text]) at 48 megadeltas worldwide. This study uncovers a robust negative association between [Formula: see text] and [Formula: see text], with correlation coefficients [Formula: see text] less than [Formula: see text] for seasonal data found in 26 of the 48 megadeltas, and less than [Formula: see text] for deseasoned data in 21 megadeltas. The anticorrelation relationship is more pronounced in large deltas, particularly near tropical climates and in river-influenced deltas. The study also underscores the significant roles of climate, morphological, and anthropogenic stratification in impacting the natural influence of freshwater discharge on . By highlighting the interconnected impacts of alterations in terrestrial water cycle upstream and [Formula: see text], this work contributes to enhancing our understanding of global ocean and climate circulation patterns and in tackling environmental issues pertaining to marine ecosystems.
海表盐度（[公式：见原文]）是全球海洋热比容环流中的一个关键参数。在大型三角洲附近，通过大集水区的内陆径流在调节盐度方面起着至关重要的作用。虽然一些区域研究已经调查了[公式：见原文]是如何受到水循环和气候要素影响的，但缺乏对内陆径流对[公式：见原文]变化贡献的全球尺度量化。在此，我们利用遥感和观测驱动的数据集来量化全球48个大型三角洲的[公式：见原文]与径流（[公式：见原文]）之间的统计关联。本研究揭示了[公式：见原文]与[公式：见原文]之间存在稳健的负相关关系，在48个大型三角洲中的26个，季节性数据的相关系数[公式：见原文]小于[公式：见原文]，在21个大型三角洲中，去季节化数据的相关系数小于[公式：见原文]。这种反相关关系在大型三角洲中更为明显，特别是在热带气候附近和受河流影响的三角洲。该研究还强调了气候、形态和人为分层在影响淡水排放对[公式：见原文]的自然影响方面的重要作用。通过突出上游陆地水循环变化与[公式：见原文]的相互关联影响，这项工作有助于增进我们对全球海洋和气候环流模式的理解，并有助于解决与海洋生态系统相关的环境问题。
