Title: Satellite-derived Land Surface Temperatures Strongly Mischaracterise Urban Heat Hazard Show Chinese title

Title: 卫星衍生的地表温度强烈地错误表征了城市热危害

Abstract: Escalating urban heat, driven by the convergence of global warming and rapid urbanization, is a profound threat to billions of city dwellers. The science directing urban heat adaptation is strongly influenced by studies that use satellite-based land surface temperature (LST), which is readily available globally and address data gaps in cities, particularly in the Global South. LST, however, is a poor surrogate for near-surface air temperature, physiologically relevant human thermal comfort, or direct human heat exposure. This flawed practice leads to issues for several downstream use cases by inflating adaptation benefits, distorting the magnitude and variability of urban heat signals across scales, and thus misguiding urban adaptation policy. We argue that satellite-based LST must be treated as a distinct indicator of surface climate, which, though relevant to the urban surface energy budget, can be frequently decoupled from human-relevant thermal impacts especially during daytime. Only by a disciplined application of this variable, combined with complementary datasets, process-based and data-driven models, as well as interdisciplinary collaboration, can urban adaptation design and policy be effectively advanced. Show Chinese abstract

Abstract: 日益加剧的城市热浪，由全球变暖和快速城市化的交汇所驱动，对数十亿城市居民构成严峻威胁。 指导城市热适应的科学强烈受到使用基于卫星的地表温度（LST）研究的影响，LST在全球范围内易于获取，并填补了城市数据的空白，尤其是在南半球国家。 然而，LST是近地面空气温度、与生理相关的体感温度或直接人体热暴露的不良替代指标。 这种有缺陷的做法会导致多个下游应用案例出现问题，包括夸大适应性收益、扭曲城市热信号在不同尺度上的幅度和变化性，从而误导城市适应政策。 我们认为，基于卫星的LST必须被视为一个独立的表面气候指标，尽管它与城市表面能量平衡相关，但在白天可能经常与人类相关的热影响脱节。 只有通过对此变量的严谨应用，结合补充数据集、基于过程的和数据驱动的模型以及跨学科合作，才能有效推进城市适应设计和政策。