To investigate the changes in atmospheric circulation in the Northern Hemisphere, geopotential height data from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) was analyzed from 1948 to 2020. A trend test was conducted on the geopotential height data to examine these changes. The results indicated significant alterations over the 70-year period in the polar regions, mid-latitudes, and other latitudes. In winter, particularly in December, a negative core of decreased geopotential height at the 10-hectopascal level was observed over the polar cap, reaching a minimum of -8 geopotential meters. Conversely, the North Pacific Ocean exhibited a maximum core of the geopotential height trend, exceeding 4.5 geopotential meters. This pattern was also evident in January and February, with a decreasing trend noted in northern Europe and the Eurasian region. In spring, a downward trend in geopotential height was observed in the area affected by the polar vortex, extending towards northeastern Russia. The analysis revealed that the most significant changes in the polar hemisphere during the first 37 years occurred in November and December. In contrast, the most substantial decreases in the polar sphere during the subsequent 37 years were noted in November, December, and March. Changes in November and March were nearly identical across both periods, with the first 37 years showing an increase in the polar hemisphere and a peak geopotential height of 140 geopotential meters in November. In the latter 37 years, a decline in the polar sphere was evident.