This preprint was under review for the journal TC but the revision was not accepted.
Understanding the Mechanism of Arctic Amplification and Sea Ice
Loss
Kwang-Yul Kim1,Jinju Kim1,Saerim Yeo2,Hanna Na3,Benjamin D. Hamlington4,and Robert R. Leben5Kwang-Yul Kim et al. Kwang-Yul Kim1,Jinju Kim1,Saerim Yeo2,Hanna Na3,Benjamin D. Hamlington4,and Robert R. Leben5
1School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
2APEC Climate Center 1463, Haeundae-gu, Busan 48058, Republic of Korea
3Ocean Circulation and Climate Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea
4Department of Ocean, Earth and Atmospheric Sciences, 4600 Elkhorn Avenue, Room 406, Old Dominion University, Norfolk, Virginia 23529, USA
5Colorado Center for Astrodynamics Research, Department of Aerospace Engineering Sciences, ECNT 320, 431 UCB, University of Colorado, Boulder, Colorado 80309-0431, USA
1School of Earth and Environmental Sciences, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
2APEC Climate Center 1463, Haeundae-gu, Busan 48058, Republic of Korea
3Ocean Circulation and Climate Research Center, Korea Institute of Ocean Science and Technology, Ansan, 15627, Republic of Korea
4Department of Ocean, Earth and Atmospheric Sciences, 4600 Elkhorn Avenue, Room 406, Old Dominion University, Norfolk, Virginia 23529, USA
5Colorado Center for Astrodynamics Research, Department of Aerospace Engineering Sciences, ECNT 320, 431 UCB, University of Colorado, Boulder, Colorado 80309-0431, USA
Received: 13 Mar 2017 – Accepted for review: 03 Apr 2017 – Discussion started: 10 Apr 2017
Abstract. Sea ice reduction is accelerating in the Barents and Kara Seas. Several mechanisms are proposed to explain the accelerated loss of polar sea ice, which remains an open question. In the present study, the detailed physical mechanism of sea ice reduction in winter is identified using the daily ERA interim reanalysis data. Downward longwave radiation is an essential element for sea ice reduction, but can only be sustained by excessive upward heat flux from the sea surface exposed to air in the region of sea ice loss. The increased turbulent heat flux is used to increase air temperature and specific humidity in the lower troposphere, which in turn increases downward longwave radiation. This feedback process is clearly observed in the Barents and Kara Seas in the reanalysis data. A quantitative assessment reveals that this feedback process is amplifying at the rate of ~ 8.9 % every year during 1979–2016. Based on this estimate, sea ice will completely disappear in the Barents and Kara Seas by around 2025. Availability of excessive heat flux is necessary for the maintenance of this feedback process; a similar mechanism of sea ice loss is expected to take place over the sea-ice covered polar region when sea ice is not fully recovered in winter.
Sea ice reduction is accelerating in the Barents-Kara Seas, and the air temperature in this region is increasing much more rapidly than the global average temperature. In this study, we examined how the rapid air temperature increase, so-called Arctic amplification, is associated with the sea ice reduction in the Barents-Kara Seas in terms of a positive feedback process between the ocean surface and the atmosphere over the sea ice reduced areas. Details of this feedback are presented/discussed.
Sea ice reduction is accelerating in the Barents-Kara Seas, and the air temperature in this...
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