Abstract High latitude regions are undergoing substantial land use and land cover change (LULCC) arising partly from a changing climate (e.g. greening of the Arctic) and climate mitigation policies (e.g. afforestation). Despite these ongoing changes, the impacts of LULCC in high latitudes are poorly understood. Studies to reduce this knowledge deficit primarily deploy regional climate models (RCMs) as observations of key variables for LULCC studies are scarce in high latitude regions. As such it is important to understand the limitations of RCMs and identify best practices for designing regional climate modelling experiments for LULCC studies at high latitudes. In this study, twelve 10-year simulations are performed over the Scandinavian Peninsula; six at convection permitting scales (dx ∼ 3 km) and six at non-convection permitting scales (dx ∼ 15 km). Two of the convection permitting simulations model the present and future climate conditions over the Scandinavian Peninsula. The present-day simulation is comprehensively evaluated for multiple variables (e.g. surface air temperature at 2 m, precipitation) using multiple sources of observations (stations, reanalysis & blended satellite products) where available. Results from the model evaluation points to the need for further model improvement in simulating precipitation and related snow processes as well as the need for observations of surface energy fluxes at high latitudes for evaluation. The remaining eight simulations differ in terms of grid spacing, background climate state (present or future climate), and land cover (conversion of grasslands to evergreen needleleaf or mixed forest). Our study highlights the strengths and limitations of common RCM design considerations, such as simulation length (single year vs. multi-years), background climate state (present vs. future climate) and model resolution (convection permitting vs. non-convection permitting). A key recommendation is that high-latitude modeling studies of LULCC should prioritize computational resources for multi-decadal and ensemble simulations over short, single experiment simulations at convection permitting scales.

中文翻译：

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为高纬度土地利用土地覆盖变化研究设计和评估区域气候模拟

摘要 高纬度地区正在经历大量土地利用和土地覆盖变化 (LULCC)，部分原因是气候变化（例如北极的绿化）和减缓气候变化的政策（例如植树造林）。尽管有这些持续的变化，但人们对 LULCC 在高纬度地区的影响知之甚少。减少这种知识短缺的研究主要部署区域气候模型 (RCM)，因为在高纬度地区对 LULCC 研究的关键变量的观察很少。因此，了解 RCM 的局限性并确定为高纬度 LULCC 研究设计区域气候模拟实验的最佳实践非常重要。在这项研究中，对斯堪的纳维亚半岛进行了 12 次 10 年模拟；六个在对流允许尺度（dx ∼ 3 km）和六个在非对流允许尺度（dx ∼ 15 km）。两个允许对流的模拟模拟了斯堪的纳维亚半岛当前和未来的气候条件。在可用的情况下，使用多种观测来源（台站、再分析和混合卫星产品）对多个变量（例如 2 m 处的地表气温、降水）对当今的模拟进行综合评估。模型评估的结果表明需要进一步改进模型来模拟降水和相关的降雪过程，以及需要对高纬度地区的表面能通量进行观测以进行评估。其余八个模拟在网格间距、背景气候状态（现在或未来气候）、和土地覆盖（草原转变为常绿针叶林或混交林）。我们的研究强调了常见 RCM 设计考虑因素的优势和局限性，例如模拟长度（一年与多年）、背景气候状态（现在与未来气候）和模型分辨率（对流允许与非对流允许） . 一个重要的建议是，LULCC 的高纬度建模研究应优先考虑用于多年代际和集合模拟的计算资源，而不是在对流允许规模的短期单一实验模拟。未来气候）和模型分辨率（允许对流与允许非对流）。一个关键的建议是，LULCC 的高纬度建模研究应优先考虑用于多年代际和集合模拟的计算资源，而不是在对流允许规模的短期单一实验模拟。未来气候）和模型分辨率（允许对流与允许非对流）。一个关键的建议是，LULCC 的高纬度建模研究应优先考虑用于多年代际和集合模拟的计算资源，而不是在对流允许规模的短期单一实验模拟。