Diatom sea ice index in marine sediment core MD01-2414 from the central Okhotsk Sea

The diatom valves were counted at magnifications of 1000 times; at least 400 valves were counted per sample. Percentages are based on the total diatom sum. The samples with poor diatom preservation (<100 diatom valves) were only used for estimation of the diatom abundance, while were not used for the discussions of diatom percentages.