Sea ice and snow characteristics from year-long transects at the MOSAiC Central Observatory

Repeated transects have become the backbone of spatially distributed ice and snow thickness measurements crucial for understanding mass balance. Here we detail at Multidisciplinary drifting Observatory Study Arctic Climate (MOSAiC) 2019–2020, which represent first such collected across an entire season. Compared with similar historical transects, MOSAiC was thin (mean depths approximately 0.1–0.3 m), while sea relatively thick first-year (FYI) second-year (SYI). SYI two distinct types: level formed from surfaces extensive melt pond cover, deformed ice. On SYI, spatial signatures refrozen ponds remained detectable in January. At beginning winter thinnest also had snow, growth rates (0.33 m month−1 FYI, 0.24 previously ponded SYI) exceeding that (0.2 month−1). By January, FYI already a greater modal (1.1 m) than (0.9 m). February, all became indistinguishable about 1.4 m. The largest thicknesses were measured May 1.7 Transects included ice, where volumes accumulated by April. remaining on exhibited typical heterogeneity form dunes. Spatial correlation length scales ranged 20 to 40 or 60 90 m, depending sampling direction, suggests known anisotropy dunes manifests patterns thickness. diverse data obtained invaluable resource model remote sensing product development.