Stakeholders need high-resolution urban climate information for city planning and adaptation to climate risks. Climate models have too coarse a spatial resolution to properly represent cities at the relevant scale, and downscaled products often fail to account for urban effects. We propose here a methodological framework for producing high-resolution urban databases that are used to drive the SURFEX-TEB land surface and urban canopy models. A historical simulation is carried out over the period 1991–2020, based on a reanalysis of the city of Philadelphia (Pennsylvania, USA). The simulation is compared with observations outside and inside the city, as well as with a field campaign. The results show good agreement between the model and observations, with average summer biases of only −1 °C and + 0.8 °C for daily minimum and maximum temperatures outside the city, and almost none inside. The simulation is used to calculate the maximum daily heat index (HIX) and to study emergency heat alerts. The HIX is slightly overestimated and, consequently, the model simulates too many heat events if not bias corrected. Overall, HIX conditions at Philadelphia International Airport are found to be suitable proxies for city-wide summer conditions, and therefore are appropriate to use for emergency heat declarations.

中文翻译：

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费城热与健康应用的高分辨率城市气候模拟


利益相关者需要高分辨率的城市气候信息来进行城市规划和适应气候风险。气候模型的空间分辨率太粗糙，无法正确代表相关尺度的城市，而缩小尺度的产品往往无法考虑城市影响。我们在此提出了一个用于生成高分辨率城市数据库的方法框架，该数据库用于驱动 SURFEX-TEB 地表和城市冠层模型。基于对费城（美国宾夕法尼亚州）市的重新分析，对 1991 年至 2020 年期间进行了历史模拟。该模拟与城市内外的观察结果以及实地活动进行了比较。结果显示，模型与观测结果吻合良好，夏季城外每日最低和最高气温的平均偏差仅为 -1 °C 和 + 0.8 °C，而城内几乎没有。该模拟用于计算每日最大高温指数 (HIX) 并研究紧急高温警报。 HIX 被稍微高估，因此，如果不纠正偏差，模型会模拟太多的热事件。总体而言，费城国际机场的 HIX 条件适合代表全市夏季条件，因此适合用于紧急高温声明。