<p>Based on the conduct of a correlation analysis, the paper shows the absence of significant relation of δ¹⁸O of Greenland and Ellesmere ice cores to changes in irradiation intensity and radiant heat transfer (the rectified value of the correlation coefficient is 0.087). No significant relation of ice core δ¹⁸O has been detected between individual Greenland and Ellesmere wells (the rectified value of the pairwise correlation coefficient is equal to 0.201). No noticeable relation has been found in the oxygen isotope composition of ice cores with an anomalous near-surface (annual, summer, and winter) air temperature in the Northern hemisphere (the rectified value of the correlation coefficient is 0.105). The analyzed isotope profiles of ice cores from the islands of Greenland and Ellesmere in the time range under consideration have no sensitivity to changes of radiator and heat regimes of the Northern hemisphere. Thus, the relations of the oxygen-isotope composition of atmospheric precipitation with the temperature in the ice cores (section) found for the current time slice do not persist, which limits the possibilities of using the method of paleoclimatic and paleotemperature reconstructions.</p>