Aerosol stratification, optical properties and radiative forcing in Venice (Italy) during ADRIEX
Aerosol stratification, optical properties and radiative forcing in Venice (Italy) during ADRIEX
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ADRIEX 期间威尼斯（意大利）的气溶胶分层、光学特性和辐射强迫
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
G. de Leeuw
中科院分区：
文献类型：
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作者：
F. Barnaba;G. Gobbi;G. de Leeuw
本研究介绍了在威尼斯（意大利）气溶胶直接辐射影响实验（ADRIEX）中进行的气溶胶光学特性和太阳辐射的地面测量。该测量地点特别受关注，因为它位于受污染的波河流域的东部边界，构成地中海盆地的北部边缘。激光雷达观测显示，对流层下部（0-4公里）存在气溶胶分层结构，由于气溶胶位于当地行星边界层（约1公里厚）上方，气溶胶光学深度超过40%。在 ADRIEX 期间遇到的各种平流状态的影响下，观察到不同的气溶胶垂直分布以及光学和微物理特性的发展。太阳光度计测量表明细颗粒（半径 < 1 µm）在消光中占主导地位，证实该地区的主要气溶胶来源是人为造成的。光度数据还显示出相对较低的气溶胶吸收（即 440 nm 处单散射反照率 > 0.92），这与欧洲和美国其他城市/工业地点发现的气溶胶吸收相当，略低于中美洲和亚洲的特征。总体而言，在 ADRIEX 期间在威尼斯测量的气溶胶光学特性转化为夏季平均日气溶胶强迫在地表处为 − 10 至 − 14 W m−2 之间，在大气顶部为 − 4 至 − 8 W m−2 之间。版权所有 © 2007 英国皇家气象学会
This study presents ground‐based measurements of aerosol optical properties and solar radiation performed in Venice (Italy) within the Aerosol Direct Radiative Impact Experiment (ADRIEX). The measurement site is of particular interest due to its location at the eastern border of the polluted Po Valley and constituting the northern edge of the Mediterranean basin. Lidar observations showed a stratified structure of aerosols in the lower troposphere (0–4 km), with more than 40% of the aerosol optical depth due to aerosol above the local planetary boundary layer (about 1 km thick). Different aerosol vertical distributions and optical and microphysical properties were observed to develop under the influence of the various advection regimes encountered during ADRIEX. Sunphotometer measurements indicated fine particles (radius < 1 µm) as dominating the light extinction, confirming the main aerosol source in the region as anthropogenic. Photometric data also revealed a relatively low aerosol absorption (i.e. a single‐scattering albedo > 0.92 at 440 nm), this being comparable to those found in other urban/industrial sites in Europe and USA, and slightly lower than those characterizing central America and Asia. Overall, the aerosol optical properties measured at Venice during ADRIEX translate into a summertime mean daily aerosol forcing between − 10 and − 14 W m−2 at the surface and between − 4 and − 8 W m−2 at the top of the atmosphere. Copyright © 2007 Royal Meteorological Society