| 摘要: | 本文利用微脈衝光達與太陽輻射儀於2005-2007年間在中壢之觀測資料，配合地面觀測資料，氣流軌跡後推及來源區域分類等方法探討在不同季節、不同氣團來源下之氣膠光學特徵。根據太陽輻射儀於2005-2007年所觀測之氣膠光學厚度(AOD500nm)月平均顯示，最高值出現在春季(0.751±0.181)、夏季(0.503±0.216)次之，而秋季(0.392±0.073)最低。至於代表粒徑分布之Ångström exponent440-870nm月平均值介於1.098-1.382之間，變化並不顯著，顯示此三年間，中壢地區垂直氣柱中粗粒與細粒氣膠比例維持相對穩定狀態。此外，進行各季節氣流來源分類與分析比對，結果顯示低層(500m)與中層(2500m)大氣之消光散射比於春季且氣團來自於東南亞與華南時為最高，分別為69±22 sr、64±19 sr，至於高層(5500m)大氣之消光散射比則較無明顯季節及源區差異。在背景狀態、生質燃燒與沙塵個案中，中壢地區氣膠光學厚度變化範圍分別為0.054-1.090、0.435-1.240及0.236- 0.839；而Ångström exponent440-870nm變化範圍則分別為0.882-1.824、0.729-1.302與0.826-1.341。 The purpose of this study is to characterize the aerosol optical properties measured by the micro-pulse lidar and sunphotometer in Chung-Li during the years of 2005 to 2007. Combining with ground level particle mass concentrations, meteorological data, backward trajectories and air mass source regions, this study also attempts to investigate the characterization of aerosol optical properties with respect to different seasons and regions. The maximum and minimum values of monthly mean aerosol optical depths at 500 nm occurred in spring (0.751±0.181) and autumn (0.392±0.073), respectively. The monthly mean of Ångström exponent 440-870nm ranged from 1.098 to 1.382, indicating a relatively stable ratio of the columnar coarse to fine particle size. Moreover, the maximum values of extinction-to-backscattering ratio of low and middle atmosphere occurred in spring with air mass coming from Southeast Asia and southern China, were 69±22 sr and 64±19 sr, respectively. The ranges of daily mean aerosol optical depths at 500 nm in background condition, biomass burning, and dust cases were 0.054- 1.090, 0.435-1.240, and 0.236-0.839, respectively. For daily mean Ångström exponent440-870nm in background condition, biomass burning, and dust cases, they ranged in 0.882-1.824, 0.729-1.302, and 0.826-1.341, respectively. |
