## 1 Introduction  
The frequent outbreaks and unprecedentedly high particulate matter (PM) concentrations of haze pollution during winter in China has drawn worldwide attention. The health hazardous of PM is size-dependent [1; 2], due to its inhalable and adverse effects on the respiratory and cardiovascular system [3]. Besides, distinctive physical or chemical processes are associated to particle size [4; 5], especially for the chemical components of a given size, such as carbonaceous species [6], which are closely related to a variety combustion processes and their secondary transformation [7; 8; 9]. However, the unpredicted temporal and spatial variations in PMs' atmospheric dynamics makes each PM pollution event totally different, even if one pollution event contains the same chemical components as another. Therefore, insight into the concentration of PM size distribution and carbonaceous components are crucial to recognize the influence of the physical and chemical development of aerosol properties during the haze formation process [10]. The temporal pollution characteristics and source apportionment of haze in winter have been extensively reported in recent few years in China (e.g., [11; 12; 13]). For example, the peak value of PM\({}_{10}\) (aerodynamic diameter 10 \(\upmu\)m and smaller) appeared in spring in northwest area of China, such as Yulin [11], because of the frequent sand storms in Asia. In comparison, PM\({}_{2.5}\) and PM\({}_{1}\) (aerodynamic diameter 2.5 or 1 \(\upmu\)m and smaller, respectively) showed similar seasonal variations with high value in winter in most cities of China [12]. It seems to be more complex for PM diurnal variations. A bimodal pattern was observed in most cities of north China due to morning and evening rush hour. A unimodal pattern associated with morning rush hour was observed in the central aera. While no clear pattern was observed in south China [13]. Therefore, the underlying aerosol formation mechanisms are so complicated that no universal controlling measurement could be used to mitigate PM fast and effectively. At present, various analogy methods aiming to comprehensively understand the haze formation mechanism and processes had been reported in previous studies, but haze-episode-based analysis was more effective to unveil the nature and differences between each haze pollution. For example, fine PM is the main contributor of the two most serious haze pollution episodes in eastern China in winter [14]. By further categorizing these into wet and dry haze, the key chemical species was attributed to sulfate in wet haze episodes and nitrate in dry haze episodes in Changzhou, a developed city in eastern China [15]. No doubt that the triggers are highly episode-dependent, especially for the secondary aerosol formation process in atmospheric PMs. Usually, carbonaceous aerosols constitute a substantial fraction of the atmospheric particles in China, accounting for approximately 20-50% of the PM\({}_{2.5}\) mass [16; 17; 18], even higher in PM\({}_{1}\)[19]. The Carbonaceous aerosols could change radiative forcing, then result in climate change. In addition, exposed in the toxic carbonaceous species longer, such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), have the potential to increase human carcinogenic risk [20]. It is noteworthy that most carbonaceous species are anthropogenic, which could be divide into organic carbon (OC) and elemental carbon (EC). EC released directly through the combustion process is the main light-absorbing fraction in the atmosphere and plays an important role in reducing visibility and aerosol radiation forcing [21]. One the other hand, OC is derived not only from primary emissions which is regarded as primary organic carbon (POC) such as coal burning, traffic and biomass burning [22], but also from secondary organic carbon (SOC) formed by its precursors through atmospheric chemical transformation [23].