Tretyakov V.Yu., Frolov S.V., Sarafanov M.I.
There is considered methodology and results of computer processing of vector ice maps of the AARI archive for the period 1998–2018. As a result of the maps processing, there were obtained long-standing series of total lengths of the Sabetta Port – the Bering Strait route legs within fast ice, within close floating ice, within the ice with presence of certain age categories of the ice and some particular concentrations of old ice and thick first-year ice for ten-days periods (decades) during April and May. The series were checked for the presence of trends by the method of integral curves, and were tested for heterogeneity using Wilcoxon–Mann–Whitney and Siegel–Tukey rank non-parametric criteria. There have been analyzed more than four thousand values of the lengths. We obtained the following conclusions: the lengths of the route within fast ice and within close floating ice with presence of old ice decreased. The lengths of the route within close floating ice, ones within close floating ice with presence of medium first-year ice and thick first-year ice increased. As well as there were increased the lengths of the route within close floating ice with partial concentration of thick first-year ice and total concentration of thick and medium first-year ice in five or more tenths. The decrease of the route length within old ice is partially compensated by the route length increase within thick first-year ice. The decrease and increase have almost the same values.