Abstract. Earth system models show wide disagreement when simulating the climate of the continents at the Last Glacial Maximum (LGM). This disagreement may be related to a variety of factors, including model resolution and an incomplete representation of Earth system processes. To assess the importance of resolution and land-atmosphere feedbacks on the climate of Europe, we performed an iterative, asynchronously coupled land-atmosphere modelling experiment that combined a global climate model, a regional climate model, and a dynamic vegetation model. The regional climate and land cover models were run at high (18 km) resolution over a domain covering the ice-free regions of Europe. Asynchronous coupling between the regional climate model and the vegetation model showed that the land-atmosphere coupling achieves quasi-equilibrium after four iterations. Modelled climate and land cover agree reasonably well with independent reconstructions based on pollen and other paleoenvironmental proxies. To assess the importance of land cover on the LGM climate of Europe, we performed a sensitivity test where we used LGM climate but present day land cover as boundary conditions. These simulations show that the LGM land-atmosphere feedback leads to colder and drier conditions around the Alps and a warmer and drier climate in southeastern Europe. Even in mid-latitude Europe where the land-atmosphere coupling strength is generally weak, and under glacial conditions with a southward displacement of the storm track and increased importance of the Atlantic, regional climate is significantly influenced by land cover.

中文翻译：

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土地覆盖在欧洲冰川气候中的作用

摘要。在模拟最后冰川期（LGM）时各大陆的气候时，地球系统模型显示出很大的分歧。这种分歧可能与多种因素有关，包括模型分辨率和地球系统过程的不完整表示。为了评估分辨率和陆地-大气反馈对欧洲气候的重要性，我们进行了迭代，异步耦合的陆地-大气建模实验，该实验结合了全球气候模型，区域气候模型和动态植被模型。区域气候和土地覆盖模型以高分辨率（18 km）在覆盖欧洲无冰地区的区域上运行。区域气候模型与植被模型之间的异步耦合表明，陆地-大气耦合经过四次迭代达到了准平衡。模拟的气候和土地覆盖与基于花粉和其他古环境代理的独立重建非常吻合。为了评估土地覆盖对欧洲LGM气候的重要性，我们进行了敏感性测试，我们使用LGM气候，但以今天的土地覆盖为边界条件。这些模拟表明，LGM的土地-大气反馈导致阿尔卑斯山周围的气候更加干燥，而东南欧的气候也更加干燥。即使在中纬度的欧洲，其陆地与大气的耦合强度通常很弱，并且在冰雪条件下，风暴轨迹向南移动，大西洋的重要性日益增强，区域气候也受到土地覆盖的显着影响。