n the present study, the quantity, duration and intensity of heat stress events in Germany as well as their future change and relation with weather types were investigated. A small ensemble of regional climate simulations with the regional climate model (RCM) COSMO-CLM driven by four general circulation models (GCMs) was used to calculate the Universal Thermal Climate Index (UTCI); the UTCI is a well-accepted thermal comfort index which we use here to quantify thermal stress. The variables entering the UTCI were bias corrected with a method that preserves their interdependencies. The projected climate changes cause a significant increase of both the mean UTCI and the number, duration and intensity of heat stress events between the control period (1981–2000) and the projection period (2031–2050). The projected future hourly frequency distribution of the UTCI at a location can be described by a shift to higher UTCI values with an almost constant shape of distribution. The investigations of the projected changes in weather types show no significant changes between the periods covered, with a few exceptions. An exception concerning heat stress events is the increase of summer anticyclonic weather types. Although more anticyclonic weather types in summer lead to an increase in heat stress events, they are not the primary cause of the projected increases. Rather, it turns out that the characteristics of the air masses associated with the weather types change towards warmer and more humid conditions.

中文翻译：

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德国UTCI气候学及其未来变化——RCM集成方法

在本研究中，研究了德国热应激事件的数量、持续时间和强度，以及它们的未来变化和与天气类型的关系。使用由四个环流模型 (GCM) 驱动的区域气候模型 (RCM) COSMO-CLM 的小型区域气候模拟集合来计算全球热气候指数 (UTCI)；UTCI 是一个广为接受的热舒适指数，我们在这里使用它来量化热应力。输入 UTCI 的变量通过一种保持其相互依赖性的方法进行了偏差校正。预测的气候变化导致控制期（1981-2000 年）和预测期（2031-2050 年）之间的平均 UTCI 以及热应激事件的数量、持续时间和强度均显着增加。一个位置的 UTCI 预计未来每小时频率分布可以通过向更高的 UTCI 值的转变来描述，并且分布形状几乎是恒定的。对天气类型预测变化的调查表明，所涵盖的时期之间没有显着变化，只有少数例外。关于热应激事件的一个例外是夏季反气旋天气类型的增加。尽管夏季更多的反气旋天气类型导致热应激事件增加，但它们并不是预计增加的主要原因。相反，事实证明，与天气类型相关的气团特征会朝着更温暖和更潮湿的条件变化。对天气类型预测变化的调查表明，所涵盖的时期之间没有显着变化，只有少数例外。关于热应激事件的一个例外是夏季反气旋天气类型的增加。尽管夏季更多的反气旋天气类型导致热应激事件增加，但它们并不是预计增加的主要原因。相反，事实证明，与天气类型相关的气团特征会朝着更温暖和更潮湿的条件变化。对天气类型预测变化的调查表明，所涵盖的时期之间没有显着变化，只有少数例外。关于热应激事件的一个例外是夏季反气旋天气类型的增加。尽管夏季更多的反气旋天气类型导致热应激事件增加，但它们并不是预计增加的主要原因。相反，事实证明，与天气类型相关的气团特征会朝着更温暖和更潮湿的条件变化。它们不是预计增加的主要原因。相反，事实证明，与天气类型相关的气团特征会朝着更温暖和更潮湿的条件变化。它们不是预计增加的主要原因。相反，事实证明，与天气类型相关的气团特征会朝着更温暖和更潮湿的条件变化。