由于高分辨率的气象-化学耦合数值模式计算成本巨大，目前国际上主要的数值天气预报业务模式基本不包含气象-化学之间的耦合作用。针对北美和欧洲等地区的研究指出，考虑了气溶胶反馈机制的模拟试验能显著改善对地面温度、相对湿度等要素的预报效果，尤其是在大污染源附近。我国的大气污染还十分严重，加上复杂的地形和气候特征，大气污染和气象条件之间的相互作用会对数值天气预报有什么样的影响？对此还缺乏基础的科学认识。因此，本研究将基于观测资料、数值天气预报资料及再分析资料，通过诊断分析和气象-化学在线耦合、非耦合数值模拟对比试验相结合，定量化考察气象-化学耦合作用对我国中长期数值天气预报效能的可能影响及时空分布特征，尤其是我国中东部、雾霾严重的冬半年；辨识不同污染过程下气象-化学耦合作用对天气系统三维结构的作用机制。该研究成果将有助于数值天气预报模式的改进，以及中长期天气和大气污染预报能力的提高。

Meteorological conditions play important roles in the formation and development of air pollution, while they could also be influenced by air pollution, such as the direct and indirect feedback effects from different aerosol particles. Due to the high cost of running a fully integrated air pollution system at the high resolution of current numerical weather prediction (NWP) systems, the coupling effect between atmosphere and chemistry has not been taken into account in the major operational NWP models in the world. A few studies, mainly in North America and Europe, suggested that the simulations with aerosol feedback mechanism can generally improve the prediction skill of temperature, relative humidity and other factors, especially near the large pollution sources. The air pollution in China is still very serious, coupled with complex terrain and climate characteristics, how can the interaction between air pollution and meteorological conditions influence the numerical weather prediction? So far, there is no scientific understanding of the issue. Therefore, based on the observational data, numerical weather prediction data and reanalysis data, and combining diagnostic analysis with online coupled atmospheric chemistry numerical simulation, this study aims to quantitatively investigate the possible influence and mechanism of the chemistry-meteorology coupling on the medium- to long-range numerical weather prediction and its spatial and temporal distribution characteristics, especially in the middle and east of China and the winter half year; and to explore the potential approaches to improve the medium- to long-range forecasting skills of weather and air quality in China.