Seasonal sea ice concentration at Signy Island, South Orkney Islands, 1982-2024

This dataset comprises covariables describing the seasonal sea ice cycle around Signy Island, South Orkney Islands between 1982 and 2024. The data are derived from satellite images using R-scripts which have been made available on Zenodo. Sea ice concentration was derived from satellite measurements of percent sea ice concentration. The satellite sea ice concentration data are modelled to provide derived covariates that together measure inter-annual differences in the sea ice season. The derived covariates are: 1) day of advance: first day when sea ice concentration exceeded 15% for at least five consecutive days; 2) day of retreat: first day when sea ice concentration remained less than 15% until the end of period; 3) ice season duration: total number of sea-ice days, between day of advance and retreat; 4) sea-ice persistence: percent time sea ice was present between day of advance and retreat; 5) day of minimum sea ice extent; 6) day of maximum extent; 7) day of minimum sea ice area; 8) day of maximum sea ice area; 9) minimum area of the ocean in km2 with at least 15% sea ice concentration; and 10) maximum area of the ocean with at least 15% sea ice concentration. Sea ice covariates are used as predictors of population dynamics of Antarctic seals at Signy Island, South Orkney Islands.

This work was funded by Natural Environment Research Council (UK) core funding to the British Antarctic Survey.

本数据集包含用于描述1982年至2024年间南奥克尼群岛锡尼岛周边海域季节性海冰循环的协变量（covariables）。本数据集依托卫星影像生成，所用的R语言脚本已在Zenodo平台公开。海冰百分浓度数据源自卫星观测的海冰百分浓度测量结果。研究人员对卫星海冰百分浓度数据进行建模，生成一系列衍生协变量，用以量化海冰季节的年际差异。所生成的衍生协变量共计10项：1）海冰推进日：海冰百分浓度连续5天及以上超过15%的首日；2）海冰消退日：海冰百分浓度持续低于15%直至观测周期结束的首日；3）海冰季时长：海冰推进日至消退日之间的总海冰日数；4）海冰持续率：海冰推进日至消退日期间海冰存在的时间占比；5）海冰最小范围日；6）海冰最大范围日；7）海冰最小面积日；8）海冰最大面积日；9）海冰百分浓度≥15%的海域最小面积（单位：平方千米）；10）海冰百分浓度≥15%的海域最大面积。上述海冰协变量可用作南奥克尼群岛锡尼岛南极海豹种群动态的预测因子。

本研究获英国自然环境研究理事会（Natural Environment Research Council, UK）向英国南极调查局（British Antarctic Survey）提供的核心经费资助。