Quantify the Contribution of Dust and Anthropogenic Sources to Aerosols in North China by Lidar and Validated with CALIPSO

Abstract

Persistent heavy haze episodes have repeatedly shrouded North China in recent years. Besides anthropogenic emissions, natural dust also contributes to the aerosols in this region. Through continuous observation by a dual-wavelength Raman lidar, the primary aerosol types and their contributions to air pollution in North China were determined. The following three aerosol types can be classified: natural dust, anthropogenic aerosols, and the mixture of anthropogenic aerosols and dust (polluted dust). The classification results are basically consistent with the classification results from the cloud–aerosol lidar and infrared pathfinder satellite observations (CALIPSO) satellite measurements. The relative bias of the lidar ratio between the Raman lidar and CALIPSO is less than 25% over 90% of the cases, indicating that the CALIPSO lidar ratio selection algorithm is reasonable. The classification results show that approximately 45% of aerosols below 1.8 km are contributed by polluted dust during our one year observations. The contribution of dust increased with height, from 6% at 500 m to 28% at 1,800 m, while the contribution of anthropogenic aerosols decreased from 49% to 25%. In addition, polluted dust is the major aerosol subtype below 1.0 km in spring (over 60%) and autumn (over 70%). Anthropogenic aerosols contribute more than 75% of air pollution in summer. In winter, anthropogenic aerosols prevailed (over 80%) in the lower layer, while polluted dust (around 60%) dominated the upper layer. Our results identified the primarily aerosol types to assess the contributions of anthropogenic and natural sources to air pollution in North China, and highlight that natural dust plays a crucial role in lower-layer air pollution in spring and autumn, while controlling anthropogenic aerosols will significantly improve air quality in winter.

Study of Persistent Haze Pollution in Winter over Jinan (China) Based on Ground-Based and Satellite Observations

“…Zhao et al [52] also indicated that burning biomass and coal emissions in autumn and winter had a significant effect on the aerosol extinction coefficient. Similarly, Wang et al [53] in their study of the contribution of dust and anthropogenic sources to aerosols in northern China showed that bottom layer anthropogenic aerosols accounted for more than 80% in winter. Moreover, Wang et al [53] indicated that aerosols have a vertical stratification feature, with mainly dust plus anthropogenic aerosols above the PBL and mainly anthropogenic aerosols in the PBL.…”

“…Similarly, Wang et al [53] in their study of the contribution of dust and anthropogenic sources to aerosols in northern China showed that bottom layer anthropogenic aerosols accounted for more than 80% in winter. Moreover, Wang et al [53] indicated that aerosols have a vertical stratification feature, with mainly dust plus anthropogenic aerosols above the PBL and mainly anthropogenic aerosols in the PBL. Figure 9 shows the regional pollution characteristics during the type 2 and type 1 haze pollution period based on the MODIS 10 km deep-blue aerosol optical depth (AOD) product at 550 nm.…”

Profiling of Aerosols and Clouds over High Altitude Urban Atmosphere in Eastern Himalaya: A Ground-Based Observation Using Raman LIDAR

“…Several studies across the world are available in the literature on aerosols and cloud characterization using ground-based LIDAR observations [38][39][40][41][42][43]. The LR was used in the chemical characterization of dust aerosols [41,42,44]. The spectral depolarization ratio was shown to differentiate ice from pure dust and smoke [40].…”