Intense summer Arctic cyclone and its relationship with Arctic sea ice simulated by the Korean Integrated Model

Sea ice declines have been continuously observed in recent decades over the Arctic Ocean by global warming. In recent years, intense storms over the Arctic have been observed more frequently, consistent with events of extreme sea ice loss. However, the interaction of storms and sea ice is not yet fully understood due to limited observations. In August 2016, an intense summer Arctic cyclone covering the Arctic ocean was occurred and maintained for almost one month, with the recorded the minimum central surface pressure of 967 hPa. During the developing stage of the cyclone, strong baroclinic instability near the cyclone center mainly contributed to the cyclone development. In addition, enhanced upward latent heat flux is also attributable to the development of Arctic cyclone. The presence or absence of sea ice would have had a significant impact on the development of storms. A large loss of sea ice was also observed along the storm's path.

In this study, a suite of sensitivity experiments with sea ice conditions are performed using the Korean Integrated Model (KIM), a global numerical weather prediction system developed by the Korea Institute of Atmospheric Prediction Systems (KIAPS) and used as the operational system at the Korea Meteorological Administration (KMA) since April 2020. The results of control experiment based on surface cycling with the reanalysis data are compared with those of sensitivity simulations using the fixed sea ice data before and after the storm. The effects on baroclinic instability, heat flux, and cyclone intensity induced by the changes in sea ice are compared. Numerical simulations are additionally performed using the initial version of KIM coupling system with earth system components including land surface, ocean, and sea ice.