Abstract: This article examines the reliability of ice data presented in the HadISST1 database (Hadley Centre Sea Ice and Sea Surface Temperature data set) of Hadley Meteorological Center (Hadley Centre for Climate Prediction and Research, Met Office, UK). The criterion for the reliability of HadISST1 database on the Northern hemisphere serves the average multiyear annual course of insolation in the Northern Hemisphere and the average multiyear annual course of insolation in 5-degree latitudinal zones at the upper boundary of the atmosphere, phase-shifted by two and three months to the past. It is revealed that the representative criterion for assessing the reliability of the business database is the average multiyear course of insolation in 5-degree latitudinal zones shifted by two months to the past. Evaluation of the data array on the Northern Hemisphere on the basis of the selected criterion demonstrates the overall high reliability of ice data reflected therein. However, there are two areas that differ in the degree of reliability of the presented data: 1) pack, drift ice with high negative values of the correlation coefficient; 2) coastal zone, in which the correlation is virtually absent (shore ice and flaw leads). The weak (or absent) correlation is observed over a significant length of the coastal zone in the Arctic Ocean, as well as in the straits and bays of the Canadian Arctic Archipelago. It is established hat the correlation coefficient of the annual course of the ice flow in the cells of the array of size 1 with the annual course of insolation of the Northern Hemisphere and the corresponding 5-degree latitudinal zones increases from the past to the present. This indicates the need for the correction of ice data in the early time range of the array (1901–1978), which precedes the time of the beginning of satellite observations.

Abstract: The subject of this research is the correlation analysis of changes in the area of sea ice in separate regions of the Arctic, and levels of internal regional correlations between multiyear monthly changes in the area of sea ice of different seas and the entire Arctic Ocean. The author also examines peculiarities in the annual amplitude course of interannual variability of monthly indices of the area of sea ice for separate districts of the Arctic, interregional links in the annual course of this amplitude of interannual variability, and determination of correlation between the annual indices of the area of sea ice with annual insolation contrast for various Arctic regions. The research method is the correlation data analysis on the area of distribution of sea ice in different districts of the Arctic and insolation contrast. The author builds an algorithm of the value forecast in the changes of sea ice area. Based on the analysis of internal correlations between multiyear and annual changes in the sea ice area in the Arctic regions, and connection with the insolation and insolation contrast, an algorithm is proposed for the value forecast of changes in the sea ice area in separate districts of the Arctic and Northern Hemisphere overall. For long-term forecast of annual values of the changes in sea ice area, the promising districts are Baffin Bay, Kara Sea, Barents Sea, Greenland Sea and Northern Hemisphere as a whole.