Changes in polar amplification in response to increasing warming in CMIP6

The climate in polar regions has experienced an obvious warming amplification due to global warming. In this study, the changes in polar amplification are analyzed in response to feedback mechanisms (including Planck, lapse rate, cloud, water vapor, albedo feedback, CO2 radiative forcing, ocean heat uptake, and atmospheric heat transport) under three warming scenarios in CMIP6-namely, SSP1-2.6, SSP2-4.5, and SSP5-8.5. The results show that, by quantifying the warming contribution of different feedback mechanisms to surface air temperature with the "radiative kernel" method, Arctic amplification (AA) is stronger than Antarctic amplification (ANA), mostly resulting from the lapse rate feedback, followed by the albedo and Planck feedbacks. Furthermore, ocean heat uptake causes stronger polar warming in winter than in summer. During winter, the lapse rate feedback causes a larger AA than ANA. The intermodel spread for both AA and ANA decrease with increasing strength of global warming from SSP1-2.6 to SSP5-8.5, and the dominant mechanisms are the Planck, lapse rate, albedo, and ocean heat uptake feedbacks. These findings help to enhance our understanding of polar regions' responses to different strengths of global warming.