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