Advances in understanding the mechanisms of Arctic amplification
image: (a) Key local feedbacks and influencing factors for AA include (1) the lapse rate feedback, (2) the surface albedo feedback, (3) the cloud and water vapor feedbacks, (4) the cloud optical depth feedback, (5) the Planck feedback, (6) oceanic and atmospheric circulation and transport, (7) changes in sensible and latent heat exchange due to sea ice thickness variations, (8) evaporation, (9) aerosol-cloud interactions, and (10) aerosol deposition; red plus signs indicate positive feedbacks within the AA process, whereas blue minus signs indicate negative feedbacks. (b) Interactions among these factors, with numbers corresponding to those in (a). The red text denotes processes that promote Arctic warming, the blue text represents processes that inhibit Arctic warming, and the orange text describes complex effects on Arctic warming; the pale blue and pale green arrows depict interactions between local feedbacks and external factors.
Credit: ©Science China Press
This study was led by Jiefeng Li, Dr. Chuanfeng Zhao, Annan Chen, Dr. Haotian Zhang and Dr. Yikun Yang from the Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University. The researchers have found that the quantified contributions of various factors to Arctic amplification (AA) vary considerably across studies, and they offer a comprehensive review of the primary drivers influencing Arctic amplification.
A series of local feedbacks play a critical role in Arctic warming. Specifically, the surface albedo feedback accelerates the process by regulating sea ice characteristics and ocean heat release. The lapse rate feedback can trap more heat near the surface, while the Planck negative feedback slightly reduces AA. The role of clouds in Arctic warming depends on the competition between shortwave radiation reflection and longwave radiation trapping, with the net effect being a warming influence. Additionally, the review highlights the influence of atmospheric circulation, ocean currents, and aerosols, which often trigger the local feedback mechanisms. However, the intricate interactions among these factors make it challenging to accurately quantify their individual contributions.
Although significant progress has been made in understanding AA, several challenges remain, including the lack of long-term, high-quality observational data, unclear mechanisms and interactions among driving factors, and insufficiently developed climate models. Overcoming these challenges is essential for improving our understanding and predictions of Arctic climate change.
See the article:
Li J, Zhao C, Chen A, Zhang H, Yang Y. 2024. Advances in understanding the mechanisms of Arctic amplification. Science China Earth Sciences, 67(12): 3814–3829, https://doi.org/10.1007/s11430-024-1438-5