Inclusions in ice layers formed by melting and refreezing processes in a Greenland ice core

Abstract In recent decades, surface melting on the inland Greenland ice sheet has increased, leading to significant meltwater-refreezing in snow and firn. Increased knowledge of physical chemical characteristics these melt features (i.e., layers) is needed help estimate future global sea-level rise. Here, using a combination microscopy spectroscopy, we investigate size, shape, location, compositions inclusions 12 layers SIGMA-A core northwestern (78°03′06″N, 67°37′42″W, 1490 m a.s.l.). layers, found exceeding 30 μm diameter that could only be formed by melting–refreezing, which classify into columnar-, particle-, rod-like inclusions. We propose smaller columnar- particle-like solid Na 2 SO 4 ⋅10H O CaSO ⋅2H form first, within grains, followed larger brines with mainly + Cl − grain boundaries. Our results suggest new proxy may identify past warm climates deeper cores for studying behavior.