资源环境科技发展态势分析平台

We compare various radiative feedbacks over the Arctic (60-90 degrees N) estimated from short-term climate variations occurring in reanalysis, satellite, and global climate model data sets using the combined Kernel-Gregory approach. The lapse rate and surface albedo feedbacks are positive, and their magnitudes are comparable. Relative to the tropics (30 degrees S-30 degrees N), the lapse rate feedback is the largest contributor to Arctic amplification among all feedbacks, followed by surface albedo feedback and Planck feedback deviation from its global mean. Both shortwave and longwave water vapor feedbacks are positive, leading to a significant positive net water vapor feedback over the Arctic. The net cloud feedback has large uncertainties including its sign, which strongly depends on the data used for all-sky and clear-sky radiative fluxes at the top of the atmosphere, the time periods considered, and the methods used to estimate the cloud feedback.

Plain Language Summary The Arctic has warmed dramatically in recent decades, with temperature increasing at a rate of about twice as fast as the global mean value. This phenomenon, commonly known as Arctic amplification, has been found in the observed and modeled climate changes. Several feedback mechanisms have been shown to contribute to Arctic amplification, but their relative importance is still very uncertain. Here we use a variety of reanalysis and satellite data sets to quantify the Arctic local feedbacks based on short-term climate variations, evaluate the feedbacks simulated in a global climate model, diagnose the impact of data set choices on the feedback estimates, and identify the sources of main uncertainties. The most disagreement is found in the estimate of cloud feedback.