近日，瑞士苏黎世联邦理工学院Lei Gu团队报道了中纬度冬季降水的不确定动力响应。2026年4月29日出版的《自然》杂志发表了这项成果。

理解降水变化对于社会和生态系统至关重要。已有研究分别阐述了人为强迫和内部变率对降水趋势的贡献，但观测与模拟结果之间仍存在差异。在北半球冬季，这些差异常被归因于主导观测趋势的非强迫性内部变率。然而，越来越多的证据表明，气候模型低估了降水对人为强迫的总体响应。

研究组表明，气候模型能够较好地重现热力学贡献，而动力学贡献则可能表现出更显著的差异。该方法将人为强迫下的热力学和动力学分量与1950—2022年冬季降水趋势中的内部变率分离开来，以探究它们对趋势差异的贡献。在地中海地区，模型模拟中的人为强迫动力学信号仅能解释约10%的观测动力学趋势，这使得检测变得困难。

在持续人为排放的情景下，预测的环流响应将增强，并与观测到的趋势模式更加接近。尽管观测记录中的内部变率可能促成了这种相似性，但结果表明，动力学响应在区域冬季降水趋势中的作用尚不确定，但可能正在显现。气候模型能否可靠地再现受强迫影响的大尺度环流响应，仍然是提高区域降水预测置信度的关键。

附：英文原文

Title: Uncertain dynamic response of mid-latitude winter precipitation

Author: Gu, Lei, Schumacher, Dominik L., Sippel, Sebastian, Fischer, Erich M., Dunkl, Istvan, Noyelle, Robin, Singh, Jitendra, Pierini, Lorenzo, Knutti, Reto

Issue&Volume: 2026-04-29

Abstract: Understanding changes in precipitation is crucial for society and ecosystems1,2. Studies have documented the respective contributions of anthropogenic forcing and internal variability to precipitation trends3,4, yet discrepancies persist between observed and simulated patterns. In Northern Hemisphere winter, these mismatches are often attributed to unforced internal variability that dominates observed trends5. However, growing evidence also indicates that climate models underestimate the total response of precipitation to human forcings6,7,8. Here we show that the thermodynamic contribution is broadly reproduced by climate models, whereas the dynamic contribution can diverge more substantially. Our approach disentangles the anthropogenic forced thermodynamic and dynamic components from internal variability in winter precipitation trends (1950–2022) to investigate their contribution to the trend discrepancies. In the Mediterranean, the forced dynamic signal from model simulations explains only about 10% of the observed dynamic trend, making detection challenging. Under continued anthropogenic emissions, the projected circulation response intensifies and more closely resembles observed trend patterns. Although internal variability in the observed record may contribute to this similarity, the results indicate an uncertain yet potentially emerging role of dynamic response in shaping regional winter precipitation trends. A reliable representation of the forced large-scale circulation response in climate models remains key for increasing confidence in regional precipitation projections.

DOI: 10.1038/s41586-026-10474-y

Source: https://www.nature.com/articles/s41586-026-10474-y