不同增暖情景下中国地区气温日较差的长期变化及其归因研究

The diurnal temperature range (DTR) change is largely reflected in the asymmetric variation of the daily maximum temperature and minimum temperature, which is not only of great significance in the ecology and agrometeorology, but also acts to be a key indicator of climate change. The observed changes in DTR over China have been extensively discussed by previous studies, but little attention was paid to the impact of the ongoing global warming on the changes of DTR over China. Using the state-of-the-art Earth System Model (CESM-CAM5), a series of sensitive experiments have been performed by varying the representative concentration paths (RCPs), combined with single factor forcing experiments, the impacts of the different warming scenarios on the long-term changes of DTR in China will be investigated here. Meanwhile, we will further examine how the changes of greenhouse gases and aerosols affect the long-term changes of DTR over China under different warming scenarios. Moreover, the changes of the atmospheric radiative and thermal-dynamical processes associated with the DTR change are further analyzed to unveil the physical mechanism related to the DTR change over China. Results of this study will not only improve our understanding on the changes in DTR under global warming, but also provide valuable information for mitigation and adaptation to the potential impacts of global warming on the climate and environment in China.

气温日较差（DTR）的变化主要体现为日最高气温和最低气温变化的不对称性，不仅在生态学，农业气象学领域有重要意义，同时也是反映气候变化的一个重要指标。前人已经广泛而深入地研究了中国地区DTR变化，但较少关注未来全球变暖情景下中国地区DTR的可能变化及其机理。本项目拟利用当前较为先进的地球系统模式CESM-CAM5，开展不同典型浓度路径（RCP）的预估试验，揭示未来不同增暖强度下中国地区DTR的长期变化特征。并结合全强迫和单因子外强迫试验，阐明温室气体，气溶胶等对中国地区DTR长期变化的影响及相对贡献。同时通过分析大气热力和动力场因子对不同增暖强度和外强迫的响应，深入探讨与DTR变化密切相关的大气辐射及动力过程对DTR的影响，从而揭示导致中国地区DTR变化的物理机制。预期研究结果将有助于我们深入理解全球变暖下中国地区DTR变化机理，为减缓和适应全球变暖对我国气候和环境的影响提供有价值的参考。

气温日较差（DTR）的变化主要体现为日最高气温和最低气温变化的不对称性，不仅在生态学，农业气象学领域有重要意义，同时也是反映气候变化的一个重要指标。然而当前少有研究关注未来全球变暖情景下中国地区DTR的可能变化及其机理。本项目着眼于全球变暖背景下中国地区气温日较差的长期变化，利用CMIP6多模式的SSP245社会经济共享路径情景下的全强迫及单因子强迫预估试验结果，来研究全球增暖对中国气温日较差可能影响及其相关机理方面的研究工作。预期研究结果将有助于我们深入理解全球变暖下中国地区DTR变化机理，为减缓和适应全球变暖对我国气候和环境的影响提供有价值的参考。