Urban buildings and parks play an important role in regulating urban climate and ecosystem services. Diurnal air temperature range (DTR a ) of rocklike buildings is commonsensically regarded as higher due to no latent heat from evapotranspiration and its smaller thermal inertia compared to wet soil. Therefore, the building DTR a is supposed to be higher than that of parks due to its building fabric. However, we found an opposite phenomenon (smaller building DTR a than that of parks), and the underlying mechanisms explaining this phenomenon are unclear. Here we conducted, in Beijing (China), a long‐term observational campaign of standard meteorological variables and radiation/energy fluxes to provide a new valuable evidence (a part of external energy) to explain this phenomenon. The observations indicated external heat energies from horizontal advection and anthropogenic heat sources. We found a significantly lower building DTR a than that of parks (ΔDTR a =2.53±1.93 °C), with a maximum difference of 3.54±1.96 °C in autumn; which was mainly attributed to higher daily minimum air temperature. We also found the large differences in air temperature contribution between the buildings and the parks happened mainly at night. The external heat sources of the building contributed 16.71% to the nighttime air temperature, which was higher than that of the parks (8.39%). The more indoor and outdoor anthropogenic heat sources in the building footprints were the major cause of the slower decrease in T min . The comparison between buildings and parks can be extensively applied to analyzing the effects of urbanization on climate. Plain Language Summary An effective mosaic of buildings and parks, as the two core elements of cities, plays an important role in regulating urban climate and providing ecosystem services. A comfortable urban environment is becoming the pivotal theme for the United Nations Sustainable Development Goals 2030 related to resilient and sustainable cities and to mitigate climate change. While the urbanization effect on the diurnal air temperature range (DTR a ) is still being debated within the climate community, we, surprisingly, found a significantly lower DTR a of buildings than of parks, which contradicts our common knowledge. The observations showed that nocturnal radiation cooling did not result in a decrease of air temperature, largely due to external heat input (60.17±22.98 W/m 2 ). Heat fluxes of both the building roofs from their large indoor heat sources and the mixed peripheral advection with anthropogenic heat discharges contributed to a higher minimum air temperature. In daytime, despite additional input from human‐induced energy, neighboring vegetation transpiration and building/tree shadows offset those heat fluxes and slowed down the air temperature increase. The findings provide new knowledge on urban heat island mitigation and climate change adaptation.
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机译：城市建筑和公园在调节城市气候和生态系统服务中发挥着重要作用。与湿土壤相比，岩质建筑的日气温范围（DTR a）通常被认为较高，这是因为没有蒸发蒸腾的潜热和较小的热惯性。因此，建筑物DTR a由于其建筑结构而被认为高于公园。但是，我们发现了相反的现象（建筑物DTR a比公园小），并且解释该现象的潜在机制尚不清楚。在这里，我们在北京（中国）进行了一次标准气象变量和辐射/能量通量的长期观察活动，以提供一个新的有价值的证据（外部能量的一部分）来解释这一现象。观测结果表明来自水平对流和人为热源的外部热能。我们发现建筑物的DTR a明显低于公园（ΔDTRa = 2.53±1.93°C），秋天的最大差异为3.54±1.96°C。这主要归因于每日最低气温较高。我们还发现建筑物和公园之间的空气温度贡献差异很大，主要发生在夜间。建筑物的外部热源对夜间气温的贡献为16.71％，高于公园（8.39％）的气温。建筑物占地面积内更多的室内和室外人为热源是T min降低较慢的主要原因。建筑物和公园之间的比较可以广泛地应用于分析城市化对气候的影响。朴素的语言摘要建筑和公园的有效拼接是城市的两个核心要素，在调节城市气候和提供生态系统服务方面发挥着重要作用。舒适的城市环境正成为联合国2030年可持续发展目标的关键主题，该目标与复原力和可持续性城市以及减轻气候变化有关。尽管气候社区仍在讨论城市化对日气温范围（DTR a）的影响，但令人惊讶的是，我们发现建筑物的DTR a明显低于公园，这与我们的常识相矛盾。观测结果表明，夜间辐射冷却并未导致空气温度下降，这主要是由于外部热量输入（60.17±22.98 W / m 2）。建筑物屋顶来自其较大的室内热源的热通量，以及人为热量排放造成的混合周向平流均有助于提高最低空气温度。在白天，尽管人类提供了额外的能量输入，但邻近的植被蒸腾作用和建筑物/树木的阴影抵消了这些热通量，并减缓了空气温度的升高。研究结果为缓解城市热岛效应和适应气候变化提供了新的知识。
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