作为全球气候变化研究中不确定性最大的因素，气溶胶的辐射效应成了近年来城市热岛研究的热点问题。现有研究成果主要侧重于气溶胶的直接辐射效应对城市热岛的影响，而关于气溶胶间接辐射效应对城市热岛影响的研究较少。本项目拟以粤港澳大湾区为例，面向大湾区优质生活圈建设的热点社会问题，立足于城市热岛研究的前沿科学问题，基于MODIS遥感资料分析近15年来研究区城市热岛强度和气溶胶光学厚度的时空演变特征及两者的相关性；利用三维变分同化技术将MODIS、FY系列、Himawari-8等多源卫星遥感数据与数值模式相结合，同化卫星遥感AOD数据以改进WRF-Chem初始场，研究气溶胶的直接辐射、间接辐射对城市热岛的影响，从现象到机理揭示气溶胶辐射效应对城市热岛效应的影响。其研究成果既是对城市热岛效应现有研究方法的有效拓展，亦可为将粤港澳大湾区建成绿色、宜居、宜业、宜游的世界级城市群提供决策支持。

As the most uncertain factor in the global climate change study, the aerosol radiative effects have become a hot topic in the urban heat island (UHI) research in recent years. Most of the existing research results are about the influences of aerosol direct radiative effect on UHI, and less is about the influences of aerosol indirect radiative effect. Taking the Guangdong-Hong Kong-Macao Greater Bay Area (GHMGBA) as an example, the project focuses on the hot social issue about the GHMGBA construction, and the frontier scientific issue of the UHI research. Firstly, the temporal and spatial evolutions of UHI intensity and aerosol optical depth (AOD) in recent 15 years will be analyzed based on MODIS data, and the qualitative relationship between AOD and UHI intensity will be discussed with statistical methods. Secondly, the AOD data of MODIS、FY satellites and Himawari-8 is used to improve the initial field of WRF-Chem based on 3-dimensional variational data assimilation techniques. Thirdly, the influences of aerosol direct and indirect radiative effects on UHI will be numerically simulated with WRF-Chem in order to systematically explain the physical mechanism of the influences of aerosol radiative effects on the intensity and distribution of UHI. This project is expected to expand the existing research methods of UHI and provide decision support to the construction of GHMGBA.