Kang, Ping; Feng, Nan; Wang, Zuwu; Guo, Yangjie; Wang, Zhen; Chen, Yarong; Zhan, Jingwen; Zhan, F. Benjamin; Hong, Song (2014). Statistical properties of aerosols and meteorological factors in Southwest China. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 119(16), 9914-9930.

Abstract
The spatial and temporal variations of aerosols and their relationships with meteorological conditions in Southwest China were studied to understand the aerosol-meteorology interactions. The spatial distribution of aerosols shows a strong "basin" effect with the highest values of Aerosol Optical Thickness at 0.55 mu m (AOT, also denoted tau(0.55)) (>0.70), fine-mode AOT (tau(0.55-fine)) (0.40 similar to 0.67), and coarse-mode AOT (tau(0.55-coarse)) (0.40 similar to 0.54), all observed in the Sichuan Basin. The temporal variation of seasonal mean tau(0.55) shows dissimilar cyclic variations, which is due to the contrary annual cycle trends of seasonal mean tau(0.55-coarse) (first decrease and then increase) and tau(0.55-fine) (first increase and then decrease). Both the results obtained from self-organizing map (SOM) model and principal component analysis (PCA) could imply the reasons for different features of the spatial and temporal variations of tau(0.55), tau(0.55-fine), and tau(0.55-coarse), and also confirm that their distributions are influenced by complex interactions among different meteorological factors. The seasonal mean tau(0.55) during the selected period is positively correlated with air pressure (PRS) and relative humidity (RHU) but negatively correlated with sunshine duration (SSD). The seasonal mean tau(0.55-fine) is positively correlated with PRS, RHU, average temperature (TEM), and precipitation (PRE). However, the seasonal mean tau(0.55-coarse) is only negatively correlated with PRE and evaporation (EVP). In particular, the tau(0.55-fine) increases (decreases) and tau(0.55-coarse) decreases (increases) with increasing (decreasing) TEM and PRE. This discrepant trend of tau(0.55-fine) and tau(0.55-coarse) might account for the weak relationships between tau(0.55) and these two meteorological factors.

DOI:
10.1002/2014JD022083

ISSN:
2169-897X