Marinelli Lorenzo, Cecilia Andrea, Casasanta Giampietro, Conidi Alessandro, Petenko Igor, Argentini Stefania
Physics Department, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy.
National Research Council of Italy, Institute of Atmospheric Sciences and Climate (CNR-ISAC), Via Fosso del Cavaliere 100, 00133 Rome, Italy.
Sensors (Basel). 2025 Jul 2;25(13):4121. doi: 10.3390/s25134121.
Understanding temperature variations within the complex urban canopy layer (UCL) is challenging due to limitations and discrepancies between temperature measurements taken in urban canyons and on rooftops. The key question is how much these measurements differ and what factors contribute to these differences. According to the guidance by the World Meteorological Organization (WMO), rooftop observations are not encouraged for urban monitoring, due to potentially anomalous microclimatic conditions, whereas measurements within urban canyons are recommended. This is particularly relevant given the increasing number of rooftop sensors deployed through citizen science, raising questions about the representativeness of such data. This study aimed to address this knowledge gap by comparing temperatures within the UCL using two sensors: one located on a rooftop, and the other positioned within the canyon. The temperature difference between these two nearby locations followed a clear diurnal cycle, peaking at over 1 °C between 12:00 and 16:00 local time, with the canyon warmer than the rooftop. This daytime warming was primarily driven by solar radiation and, to a lesser extent, by wind speed, but only under clear-sky conditions. During the rest of the day, the temperature difference remained negligible.
由于城市峡谷和屋顶的温度测量存在局限性和差异，了解复杂城市冠层（UCL）内的温度变化具有挑战性。关键问题是这些测量值有多大差异以及哪些因素导致了这些差异。根据世界气象组织（WMO）的指导意见，由于可能存在异常的微气候条件，不鼓励在城市监测中使用屋顶观测数据，而建议在城市峡谷内进行测量。鉴于通过公民科学部署的屋顶传感器数量不断增加，这一情况尤为重要，这引发了对此类数据代表性的质疑。本研究旨在通过使用两个传感器比较UCL内的温度来填补这一知识空白：一个位于屋顶，另一个位于峡谷内。这两个相邻位置之间的温差呈现出明显的昼夜循环，在当地时间12:00至16:00之间峰值超过1°C，峡谷温度高于屋顶。这种白天的升温主要由太阳辐射驱动，在较小程度上由风速驱动，但仅在晴空条件下如此。在一天中的其余时间，温差可忽略不计。
