Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510640, China.
Institute of Tropical and Marine Meteorology/Guangdong Provincial Key Laboratory of Regional Numerical Weather Prediction, China Meteorological Administration, Guangzhou 510640, China.
Sci Total Environ. 2018 May 1;622-623:481-492. doi: 10.1016/j.scitotenv.2017.11.348. Epub 2017 Dec 13.
The sun-photometer data from 2011 to 2013 at Panyu site (Panyu) and from 2007 to 2013 at Dongguan site (Dg) in the Pearl River Delta region, were used for the retrieving of the aerosol optical depth (AOD), single scattering albedo (SSA), Ångström exponent (AE) and volume size distribution of coarse- and fine-mode particles. The coarse-mode particles presented low AOD (ranging from 0.05±0.03 to 0.08±0.05) but a strong absorption property (SSA ranged from 0.70±0.03 to 0.90±0.02) for the wavelengths between 440 and 1020nm. However, these coarse particles accounted for <10% of the total particles. The AOD of fine particles (AODf) was over 3 times as large as that of coarse particles (AODc). The fine particles SSA (SSAf) generally decreased as a function of wavelength, and the relatively lower SSAf value in summer was likely to be due to the stronger solar radiation and higher temperature. More than 70% of the aerosols at Panyu site were dominated by fine-mode absorbing particles, whereas about 70% of the particles at Dg site were attributed to fine-mode scattering particles. The differences of the aerosol optical properties between the two sites are likely associated with local emissions of the light-absorbing carbonaceous aerosols and the scattering aerosols (e.g., sulfate and nitrate particles) caused by the gas-phase oxidation of gaseous precursors (e.g., SO and NO). The size distribution exhibited bimodal structures in which the accumulation mode was predominant. The fine-mode volume showed positive dependence on AOD (500nm), and the growth of peak value of the fine-mode volume was higher than that of the coarse volume. Both the AOD and SSA increased with increasing relative humidity (RH), while the AE decreased with increasing RH. These correlations imply that the aerosol properties are greatly modified by condensation growth.
利用珠江三角洲地区番禺站（Panyu）2011 年至 2013 年和东莞站（Dg）2007 年至 2013 年的太阳光度计资料，反演气溶胶光学厚度（AOD）、单次散射反照率（SSA）、Angstrom 波长指数（AE）和粗细模态粒子体积谱分布。粗模态粒子的 AOD 较低（0.05±0.03 至 0.08±0.05），但是在 440nm 至 1020nm 波长范围内对光的吸收性很强（SSA 为 0.70±0.03 至 0.90±0.02）。然而，这些粗模态粒子只占总粒子的不到 10%。细模态粒子的 AOD（AODf）是粗模态粒子的 AOD（AODc）的 3 倍多。细模态粒子的 SSA（SSAf）通常随着波长的增加而降低，夏季相对较低的 SSAf 值可能是由于更强的太阳辐射和更高的温度。番禺站超过 70%的气溶胶以细模态吸收性粒子为主，而东莞站约 70%的粒子属于细模态散射性粒子。这两个站点的气溶胶光学性质差异可能与光吸收性碳质气溶胶和散射性气溶胶（如硫酸盐和硝酸盐粒子）的局部排放有关，这些气溶胶是由气态前体（如 SO 和 NO）的气相氧化产生的。粒度分布呈双峰结构，其中积聚模态占主导地位。细模态体积与 AOD（500nm）呈正相关，细模态体积峰值的增长高于粗模态体积。AOD 和 SSA 随相对湿度（RH）的增加而增加，AE 随 RH 的增加而降低。这些相关性表明气溶胶性质受凝结增长的影响很大。
