While previous studies mainly focused on low-frequency variabilities of mean or extreme temperature, it remains unclear how the high-frequency variability (HFV) of temperature changes within few days and to what degree local urbanization contributes to these changes. In this study, we examine the changes of temperature HFVs over South China and quantify their urbanization effects. We find that the HFV there shows a discernible spatial dependence with higher values in northern inland and lower in southern coastal regions. The study area has experienced increasing HFV trends since the 1980s, and these trends are especially stronger in highly developed regions, e.g., the Pearl River Delta. We further estimate that urbanization induces additional intensifying effects of 0.06, 0.10, and 0.10 °C/100 yr for HFV at the time scales of 1, 2, and 5 days, respectively, and these urbanization effects contribute to 46.2%, 43.5%, and 37.0% of the total trends of HFV in the urban areas. Our findings are helpful for mitigating the increasing threats of HFV and promoting sustainable development in populated urban areas.

虽然以前的研究主要集中在平均或极端温度的低频变化，但尚不清楚温度的高频变化（HFV）如何在几天内发生变化，以及当地城市化在多大程度上促成了这些变化。在这项研究中，我们研究了华南地区气温 HFV 的变化，并量化了它们的城市化效应。我们发现那里的 HFV 表现出明显的空间依赖性，北部内陆地区值较高，南部沿海地区值较低。自 1980 年代以来，研究区域经历了不断增加的 HFV 趋势，这些趋势在珠江三角洲等高度发达地区尤为明显。我们进一步估计，在 1、2 和 5 天的时间尺度上，城市化对 HFV 产生 0.06、0.10 和 0.10 °C/100 年的额外强化效应，这些城市化效应分别占城市地区 HFV 总趋势的 46.2%、43.5% 和 37.0%。我们的研究结果有助于减轻日益严重的 HFV 威胁并促进人口稠密的城市地区的可持续发展。