Changing relationship between Arctic sea ice and Korean summer temperature variabilities

Abstract

Surface air temperatures in the Arctic have been warming in much faster rate than the rest of globe. The ongoing accelerated warming in the Arctic has resulted in the rapid melting of sea ice in the recent decades. More interestingly, the Arctic was suggested to affect weather and climate conditions in the mid-latitude. For this Arctic – midlatitude connection, vast amount of research has been devoted to winter season. However, new studies started to examine this linkage during summer season. Our research explores the alterations in atmospheric patterns that are linked to the Barents-Kara Sea ice concentration and the temperatures on the Korean Peninsula in particular its change from earlier period of 1979-2000 to later period of 2001-2022. The decrease in sea ice concentration in the Barents-Kara Sea in July is highly correlated with anomalously warmer temperatures over the Korean Peninsula in August throughout the entire study period. More interestingly, the inverse relationship is amplified in the later periods. Simultaneously, there is an increasing negative correlation between sea ice concentration in the Barents-Kara Sea and upper-level atmospheric variables. Specifically, the geopotential height at 200hPa appears to resemble the CGT pattern, which is associated with the Korean Peninsula heatwave in the earlier period. This seemed to be a potential explanation for the change in the correlation between sea ice concentration in the Barents-Kara Sea and temperature in the Korean Peninsula, but it was found to be rarely related to sea ice concentration. Also, the variability of sea ice concentration in the Barents-Kara Sea was similar in both periods, making it difficult to determine a potential cause. The correlation between sea ice concentration north of Greenland in August and Korean Peninsula surface temperature in September is reversed. When we look at sea ice variability to find the cause of the change in the correlation between sea ice concentration north of Greenland and Korean Peninsula surface temperature, the variability is higher in the later period than in the earlier period. This suggests a possible reversal of the correlation. In conclusion, our results suggest that the relationship between summer Korean Peninsula surface temperature and sea ice concentration in the Barents-Kara Sea and northern Greenland has changed during the early and late periods. Nevertheless, the exact cause of these changes remains to be determined.