Status: this preprint was under review for the journal TC but the revision was not accepted.
Understanding the Mechanism of Arctic Amplification and Sea Ice
Kwang-Yul Kim,Jinju Kim,Saerim Yeo,Hanna Na,Benjamin D. Hamlington,and Robert R. Leben
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.
How to cite. Kim, K.-Y., Kim, J., Yeo, S., Na, H., Hamlington, B. D., and Leben, R. R.: Understanding the Mechanism of Arctic Amplification and Sea Ice
Loss, The Cryosphere Discuss. [preprint], https://doi.org/10.5194/tc-2017-39, 2017.
Received: 13 Mar 2017 – Discussion started: 10 Apr 2017
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...