Abstract. High resolution, downscaled climate model data are used in a wide variety of applications in environmental sciences. Here we present the CHELSA-TraCE21k downscaling algorithm to create global monthly climatologies for temperature and precipitation at 30 arcsec spatial resolution in 100 year time steps for the last 21,000 years. Paleo orography at high spatial resolution and at each timestep is created by combining high resolution information on glacial cover from current and Last Glacial Maximum (LGM) glacier databases with the interpolation of a dynamic ice sheet model (ICE6G) and a coupling to mean annual temperatures from CCSM3-TraCE21k. Based on the reconstructed paleo orography, mean annual temperature and precipitation was downscaled using the CHELSA V1.2 algorithm. The data were validated by comparisons with the glacial extent of the Laurentide ice shield based on expert delineations, proxy data from Greenland ice cores, historical climate data from meteorological stations, and a dynamic simulation of species a distribution throughout the Holocene. Validations show that CHELSA TraCE21k output creates a reasonable representation of the distribution of temperature and precipitation through time at a high spatial resolution, and simulations based on the data are capable of detecting effective LGM refugia of species.

中文翻译：

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CHELSA-TraCE21k v1.0。自上次冰川最大以来的瞬态温度和降水数据的缩减

摘要。高分辨率，按比例缩小的气候模型数据被用于环境科学中的各种应用中。在这里，我们介绍了CHELSA-TraCE21k降尺度算法，该算法可在过去21,000年的100年时间步长中以30 arcsec空间分辨率创建温度和降水的全球月度气候。通过将来自当前和最后冰川最大（LGM）冰川数据库的冰川覆盖的高分辨率信息与动态冰盖模型（ICE6G）的插值以及对年平均温度的耦合相结合，来创建具有高空间分辨率和每个时间步长的古地形学来自CCSM3-TraCE21k。基于重建的古地形，使用CHELSA V1.2算法降低了年平均气温和降水量。通过与Laurentide冰盾的冰川范围进行比较，基于专家的描述，格陵兰冰芯的代理数据，气象站的历史气候数据以及整个全新世的物种动态模拟，对数据进行了验证。验证表明，CHELSA TraCE21k输出可在高空间分辨率下合理地表示温度和降水随时间的分布，并且基于这些数据的仿真能够检测到有效的LGM物种避难所。