Arctic ice core sea salt simulations for 1991-2015 CE produced using p-TOMCAT chemical transport model

Interpretation of ice core marine chemistry is often ambiguous because multiple processes influence the signal preserved. Using a chemical transport model, we investigate the relative influence of sea ice and meteorology changes on sea salt sodium records from Arctic ice cores. For inland Greenland cores, our simulations suggest that the sodium budget is dominated by the open ocean source and that inter-annual variability is primarily driven by meteorological conditions not the strength of aerosol emissions. In contrast, for coastal high Arctic cores, the sea ice surface is the principal aerosol source, with inter-annual variability strongly linked to aerosol emissions. High Arctic ice cores may therefore record decadal to centennial scale Holocene sea ice variability. However, any relationship between ice core sodium and sea ice may depend on how sea ice thickness or seasonality impacts sea salt emissions. Field-based observations are urgently required to constrain this. Simulations performed using Cambridge p-TOMCAT chemical transport model which represents the emission, transport and deposition of sea salt aerosol sourced from the open ocean (OOSS) and sea ice surface (SISS). p-TOMCAT is a 3D global model with a spatial resolution of 2.8° x 2.8° across 31 vertical sigma-pressure levels driven by ERA-Interim wind, temperature and humidity fields and HadISST-derived sea ice fraction.冰芯海洋化学记录的解译通常存在歧义，这是因为多种过程会对其保存的信号产生影响。本研究借助化学传输模型，探究海冰与气象变化对北极冰芯中海盐钠记录的相对影响。 针对格陵兰内陆冰芯，模拟结果显示钠收支主要受开放海洋源控制，而年际变率主要由气象条件驱动，而非气溶胶排放强度。与之相反，北极沿海高纬度冰芯的主要气溶胶来源为海冰表面，其年际变率与气溶胶排放强度紧密相关。因此，北极高纬度冰芯或可记录全新世内年代际至百年尺度的海冰变化。不过，冰芯钠记录与海冰之间的任何关联，可能取决于海冰厚度或季节变化如何影响海盐排放。亟需开展野外观测以厘清该关联机制。 本研究采用剑桥p-TOMCAT化学传输模型开展模拟，该模型可表征源自开放海洋（Open Ocean Source, OOSS）与海冰表面（Sea Ice Surface Source, SISS）的海盐气溶胶的排放、传输与沉降过程。p-TOMCAT是一款三维全球模型，其空间分辨率为2.8°×2.8°，包含31个垂直西格玛气压层，驱动数据为ERA-Interim再分析的风场、温度场与湿度场，以及基于HadISST数据集得到的海冰覆盖率。