Sammendrag
During the freezing period, the consolidated part of sea ice ridges is usually up to 1.6–1.8 times thicker than surrounding level ice. Meanwhile, during the melt season, ridges are often observed fully consolidated, but this process is not fully understood. We present the evolution of the morphology and temperature of a first-year ice ridge studied during MOSAiC from its formation to advanced melt. From October to May the draft of first-year ice at the MOSAiC coring site increased from 0.3 m to 1.5 m, while from January to July the ridge consolidated layer thickness reached 3.9 m. We observed several types of ridge consolidation. From the beginning of January until mid-April, the ridge consolidated slowly by heat loss to the atmosphere with a total consolidated layer growth of 0.7 m. From mid-April to mid-June, there was a rapid increase in ridge consolidation rates despite conductive heat fluxes did not increase. In this period, the mean thickness of the consolidated layer increased by 2.2 m. Our observations suggest that this sudden change was related to the transport of snow-slush inside the ridge keel via adjacent open leads that decreased ridge macroporosity which could result in more rapid consolidation. Such observations are important for the mass balance of deformed sea ice and snow.
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