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The rapid loss of Arctic sea ice is a striking consequence of anthropogenic global warming. Its remote impacts on mid‐latitude weather and climate have attracted scientific and media attention. In this study, we use a hybrid (dynamical plus machine‐learning) atmospheric model—Google's NeuralGCM—to investigate the mid‐latitude atmospheric circulation responses to Arctic sea‐ice loss for the first time. We conduct experiments in which NeuralGCM is forced with pre‐industrial and future sea‐ice concentrations following the protocol of the Polar Amplification Model Intercomparisom Project. To assess the performance of NeuralGCM, we compare the results with those simulated by two physics‐based climate models. NeuralGCM produces a comparable response of near‐surface warming to sea‐ice loss and the subsequent weakened zonal wind in mid‐latitudes. However, there is a substantial discrepancy between the two models' stratospheric responses, where different temperature responses in these models are associated with different zonal wind and geopotential height responses. Further investigation of North Atlantic blocking shows that NeuralGCM produces stronger, more frequent, and more realistic blocking events. Our results demonstrate the capability of NeuralGCM in simulating the tropospheric responses to Arctic sea‐ice loss, but improvements may be needed for the stratospheric representation.
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This content will become publicly available on December 6, 2026
Causes and consequences of Arctic amplification elucidated by coordinated multimodel experiments
Abstract Human-induced warming is amplified in the Arctic, but its causes and consequences are not precisely known. Here, we review scientific advances facilitated by the Polar Amplification Model Intercomparison Project. Surface heat flux changes and feedbacks triggered by sea-ice loss are critical to explain the magnitude and seasonality of Arctic amplification. Tropospheric responses to Arctic sea-ice loss that are robust across models and separable from internal variability have been revealed, including local warming and moistening, equatorward shifts of the jet stream and storm track in the North Atlantic, and fewer and milder cold extremes over North America. Whilst generally small compared to simulated internal variability, the response to Arctic sea-ice loss comprises a non-negligible contribution to projected climate change. For example, Arctic sea-ice loss is essential to explain projected North Atlantic jet trends and their uncertainty. Model diversity in the simulated responses has provided pathways to observationally constrain the real-world response.
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- Award ID(s):
- 2311541
- PAR ID:
- 10655597
- Publisher / Repository:
- Nature Portfolio
- Date Published:
- Journal Name:
- Communications Earth & Environment
- ISSN:
- 2662-4435
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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