###### Abstract  
The intergovernmental Panel on Climate Change has reported that atmospheric aerosol radiative forcing could have significant effect on climate change [1]. Aerosols affect Earth's radiation balance directly by scattering and absorbing solar shortwave and longwave radiation. They also act as condensation nuclei for clouds, thereby changing the cloud's microphysical properties and life cycles and thus, indirectly affect the climatic system [2]. China's rapid economic growth, urbanization, population expansion, and increased industrial activity have led to increasing amounts of particles being discharged into the environment, resulting in frequent air pollution events [3]. The World Health Organization has indicated that aerosols (especially fine particles) could produce adverse effects on human health [4] and therefore, serious regional haze incidents have been investigated in many parts of China, including the Pearl River Delta, Yangtze River Delta, and Beijing-Tianjin-Hebei region (BTH) [5]. Haze episodes have attracted considerable attention from researchers and many experiments have been conducted to study haze all over the world. Since 1990 in BTH, the number of days with haze has increased gradually and the visibility has decreased continuously between 1980 and 2008 [6]. Many air pollutants accumulate during haze episodes, leading to an increase of the aerosol optical depth (AOD) [7]. In northern China, high aerosol loading at the surface has led to a decreasing trend in solar radiation at a rate of 30-40 W\(\cdot\)m\({}^{-2}\) per day [8]. [PERSON] _et al._ reported that the concentration of PM\({}_{2.5}\) doubles on haze days [9]. [PERSON] _et al._ also discovered that on hazy or foggy days, the concentration of water-soluble ions is more than 10 times that during normal weather [10]. In Guangzhou, fine particles were found to play a dominant role during haze and they exhibited a double peak in the particle size distribution [11]. A long-term study of haze in Nanjing has indicated a rapid increase in the concentration of aerosols with diameters of 0.6-1.4 \(\upmu\)m, which has led to a significant growth in the scattering coefficient [12]. In hazy regions, increased amounts of absorbing aerosols, (e.g., dust and black carbon (BC)) can induce anomalous water cycle feedback, which can affect the general circulation and alter the dynamical state of the entire monsoon system [13; 14; 15]. Furthermore, atmospheric radiation mechanisms and agricultural activities could also be affected by haze on regional and global scales. Soot particles play the role of an absorbent, which heats the atmosphere and cools the Earth's surface [16; 17; 18; 19; 20]. Experts have estimated that regional haze events in China could lead to a 5%-30% decrease in crop yields [21]. Generally, haze episodes are air pollutant layers consisting of anthropogenic sulfate, nitrate, organics, BC, soot, and fly ash, as well as natural aerosols such as sea salt and mineral dust. Research has indicated that common hazes are caused mainly by anthropogenic emission sources, such as communications and transportation industries, industrial production, and cooking [22]. The study by [PERSON] _et al._ proved that haze pollutants comprise particles both from local emission sources and from long distance transport [23]. Owing to weather patterns, particles can be transferred on the continental scale, which greatly affects the air quality of locations in downwind directions [24; 25]. Furthermore, [PERSON] _et al._ and [PERSON] _et al._ studied the phase and mixture status of aerosols and discovered that hazes inthe North China Plain (NCP) during June are caused primarily by particles generated from the combustion of agricultural biomass [26,27]. Most haze studies in China have been undertaken in eastern [12], southern coastal [11], and northern areas [3,10,16], which have traditionally been the most polluted. However, central China has also experienced a series of significant haze episodes.