Using transfer functions, this study reconstructed the ice-free period (IFP) that occurred 4.7 kya in the southern Chukchi Sea, based on the comparison between the observed data and the chemical composition of sediments accumulated during the observation period. During the analysis, a double normalization of the chemical element contenton rubidium and minimax - was implemented for the first time. It was established that the duration of the IFP varied between 90 and 140 days/year. The highest values are observed in the 21st century and 4–5 kya, coinciding with Pacific water inflow through the Bering Strait. The reconstruction of water masses based on diatom thanatocoenosis has revealed the considerable impact of the Alaskan coastal current on the duration of the IFP. The penetration of its waters to the west during the following time periods - 2750-2550, 1450–800, 350–0 cal yr BP - led to an increase in the duration of the IFP in the central part of the sea by 10–15 days, relative to background values. As a result, the identified variations in the duration of the IFP in the southern Chukchi Sea do not coincide with global climate events of the last millennium, but are clearly demonstrated by an increase in the IFP during the Little Ice Age. Currently, the influence of the Alaskan coastal water is summed up by the effect of increasing global temperatures and Pacific water inflow, which has led to a sharp increase in the IFP in the last few decades.

本研究使用传递函数，根据观测数据与观测期间积聚的沉积物的化学成分之间的比较，重建了楚科奇海南部4.7 kya发生的无冰期（IFP）。在分析过程中，首次对rub和minimax上的化学元素含量进行了双重标准化。可以确定，IFP的持续时间为每年90至140天不等。最高值出现在21世纪和4-5 kya，与通过白令海峡流入太平洋的海水相吻合。基于硅藻锥虫病的水团的重建揭示了阿拉斯加沿海流对IFP持续时间的巨大影响。在随后的2750-2550年，1450-800年，350-0 cal BP期间，水域向西渗透，导致海中部的IFP持续时间增加了10-15相对于背景值的天数。结果，在楚科奇海南部，IFP持续时间的确定变化与上个千年的全球气候事件并不吻合，但是在小冰河时期IFP的增加清楚地证明了这一点。当前，全球温度升高和太平洋水流入增加了对阿拉斯加沿海水域的影响，这导致近几十年来IFP急剧增加。结果，在楚科奇海南部，IFP持续时间的确定变化与上个千年的全球气候事件并不吻合，但是在小冰河时期IFP的增加清楚地证明了这一点。当前，全球温度升高和太平洋水流入增加了对阿拉斯加沿海水域的影响，这导致近几十年来IFP急剧增加。结果，在楚科奇海南部，IFP持续时间的确定变化与上个千年的全球气候事件并不吻合，但是在小冰河时期IFP的增加清楚地证明了这一点。当前，全球温度升高和太平洋水流入增加了对阿拉斯加沿海水域的影响，这导致近几十年来IFP急剧增加。