The urban heat island (UHI) effect, a phenomenon of local warming over urban areas, is the most well-known impact of urbanization on climate. Globally consistent estimates of the UHI intensity (UHII) are crucial for examining this phenomenon across time and space. However, publicly available UHII datasets are limited and have several constraints: (1) they are for clear-sky surface UHII, not all-sky surface UHII and canopy (air temperature) UHII; (2) the estimation methods often neglect anthropogenic disturbance, introducing uncertainties in the estimated UHII. To address these issues, this study proposes a new dynamic equal-area (DEA) method that can minimize the influence of various confounding factors on UHII estimates through a dynamic cyclic process. Utilizing the DEA method and leveraging various gridded temperature data, we develop a global-scale (>10,000 cities), long-term (over 20 years by month), and multi-faceted (clear-sky surface, all-sky surface, and canopy) UHII dataset. Based on these estimates, we provide a comprehensive analysis of the UHII and its trends in global cities. The UHII is found to be greater than zero in >80% of cities, with global annual average magnitudes around 1.0 °C (day) and 0.8 °C (night) for surface UHII, and close to 0.5 °C for canopy UHII. Furthermore, an interannual upward trend in UHII is observed in >60% of cities, with global annual average trends exceeding 0.1 °C/decade (day) and over 0.06 °C/decade (night) for surface UHII, and slightly surpassing 0.03 °C/decade for canopy UHII. Notably, there exists a positive correlation between the magnitude and trend of UHII, suggesting that cities with stronger UHII tend to experience faster growth in UHII. Additionally, discrepancies in UHII are found between different temperature data, stemming not only from distinctions in data types (surface or air temperature) but also from differences in data acquisition times (Terra or Aqua), weather conditions (clear-sky or all-sky), and processing methodologies (with or without gap filling). Overall, our proposed method, dataset, and analysis results have the potential to provide valuable insights for future urban climate studies. The UHII dataset is publicly available at .

中文翻译：

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全球城市热岛强度数据集：生成、比较和分析


城市热岛效应（UHI）是城市地区局部变暖的现象，是城市化对气候最著名的影响。对城市热岛强度 (UHII) 的全球一致估计对于跨时间和空间研究这一现象至关重要。然而，公开可用的UHII数据集是有限的，并且有几个限制：（1）它们是针对晴空表面UHII，而不是全天空表面UHII和冠层（气温）UHII； (2)估算方法往往忽视人为干扰，给UHII估算带来不确定性。为了解决这些问题，本研究提出了一种新的动态等面积（DEA）方法，可以通过动态循环过程最大限度地减少各种混杂因素对UHII估计的影响。利用DEA方法并利用各种网格温度数据，我们开发了全球范围（>10,000个城市）、长期（超过20年按月）和多方面（晴空表面、全天空表面和Canopy）UHII 数据集。基于这些估计，我们对全球城市的城市健康指数及其趋势进行了全面分析。研究发现，超过 80% 的城市的 UHII 大于零，全球年平均地表 UHII 强度约为 1.0 °C（白天）和 0.8 °C（夜间），而冠层 UHII 则接近 0.5 °C。此外，超过60%的城市观察到UHII的年际上升趋势，全球年平均趋势超过0.1°C/十年（白天），地表UHII超过0.06°C/十年（夜间），略超过0.03°冠层 UHII 摄氏度/十年。值得注意的是，UHII 的强度和趋势之间存在正相关关系，这表明 UHII 较强的城市往往会经历较快的 UHII 增长。 此外，不同温度数据之间存在 UHII 差异，这不仅源于数据类型（地表温度或气温）的差异，还源于数据采集时间（Terra 或 Aqua）、天气条件（晴空或全空）的差异。 ）和处理方法（有或没有间隙填充）。总的来说，我们提出的方法、数据集和分析结果有可能为未来的城市气候研究提供有价值的见解。 UHII 数据集可在 上公开获取。