Year: 2025
Type: article
Abstract: The role of cloud feedbacks in Arctic amplification (AA) of anthropogenic warming remains unclear. Traditional feedback analysis diagnoses the net cloud feedback as strongly positive in the tropics but either weak or negative in the Arctic, suggesting that AA would be amplified if cloud feedbacks were suppressed. However, in cloud-locking experiments using the slab ocean version of the Energy Exascale Earth System Model (E3SM), we find that suppressing cloud feedbacks results in a substantial decrease in AA under greenhouse gas forcing. We show that the increase in AA from cloud feedbacks arises from two main mechanisms: 1) the additional energy contributed by positive cloud feedbacks in the tropics leads to increased poleward moist atmospheric heat transport (AHT) which then amplifies Arctic warming; and 2) the additional Arctic warming is amplified by positive noncloud feedbacks in the region, together making extrapolar cloud feedbacks amplify AA. We also find that cloud changes can modify the strength of noncloud feedback, but that modification has a small effect on Arctic warming. We further examine the role of cloud feedbacks in AA using a moist energy balance model, which demonstrates that interactions of cloud feedbacks with moist AHT and other positive feedbacks dominate the influence of clouds on the pattern of surface warming. However, the contribution of cloud-induced changes in noncloud feedbacks on AA is relatively minor. These results demonstrate that traditional attributions of AA, that are based on local feedback analysis, overlook key interactions between extrapolar cloud changes, poleward AHT, and noncloud feedbacks in the Arctic.
Source: Journal of Climate
Language: English
Subfield: Global and Planetary Change
Field: Environmental Science
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Funders: National Science Foundation, U.S. Department of Energy, Battelle, National Natural Science Foundation of China, Climate Extremes, National Oceanic and Atmospheric Administration, Office of Science, Biological and Environmental Research, Climate Program Office, Pacific Northwest National Laboratory
Awards: G118807735, G1194053398, G1242655424, G1286236842, G1337544421, CAREER: Understanding the Time- and State-Dependence of Climate Sensitivity, G1756126698, G1863003419, G2163009439, G223002938, G2988778103, G3083819904, G3597922575, G3933667097, G419881185, G42916606, G4423186197, G4501827968, G4643306197, G498139845, G538270251, G5726405315, G575939937, G613759197, G6225852585, G704498496, G7787287669, G84288863, G969889393
OpenAlex ID: W4411204662