Journal cover Journal topic
The Cryosphere An interactive open-access journal of the European Geosciences Union
The Cryosphere, 10, 2191-2202, 2016
© Author(s) 2016. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
22 Sep 2016
Mechanism of seasonal Arctic sea ice evolution and Arctic amplification
Kwang-Yul Kim1, Benjamin D. Hamlington2, Hanna Na3, and Jinju Kim1 1School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
2Department of Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfork, Virginia 23529, USA
3Ocean Circulation and Climate Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea
Abstract. Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents–Kara seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice reduction warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be free of ice. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents–Kara seas and Laptev, East Siberian, Chukchi, and Beaufort seas.

Citation: Kim, K.-Y., Hamlington, B. D., Na, H., and Kim, J.: Mechanism of seasonal Arctic sea ice evolution and Arctic amplification, The Cryosphere, 10, 2191-2202,, 2016.
Publications Copernicus
Short summary
Analysis reveals that “Arctic amplification”, lower tropospheric winter temperature rise in the Arctic, is due to sea ice melting and the resulting increase in the amount of turbulent heat flux from the ocean. As a result of increased turbulent heat flux, lower atmosphere warms up, resulting in increased downward longwave radiation. A detailed physical mechanism is presented together with an explanation why this positive feedback process is currently possible in the Barents–Kara seas.
Analysis reveals that “Arctic amplification”, lower tropospheric winter temperature rise in...