The Hong Kong Polytechnic University, Department of Land Surveying and Geo-Informatics, Hung Hom, Hong Kong.
J Air Waste Manag Assoc. 2013 Sep;63(9):1098-110. doi: 10.1080/10962247.2013.801372.
Hong Kong's surface visibility has decreased in recent years due to air pollution from rapid social and economic development in the region. In addition to deteriorating health standards, reduced visibility disrupts routine civil and public operations, most notably transportation and aviation. Regional estimates of visibility solved operationally using available ground and satellite-based estimates of aerosol optical properties and vertical distribution may prove more effective than standard reliance on a few existing surface visibility monitoring stations. Previous studies have demonstrated that such satellite measurements correlate well with near-surface optical properties, despite these sensors do not consider range-resolved information and indirect parameterizations necessary to solve relevant parameters. By expanding such analysis to include vertically resolved aerosol profile information from an autonomous ground-based lidar instrument, this work develops six models for automated assessment of surface visibility. Regional visibility is estimated using co-incident ground-based lidar, sun photometer visibility meter and MODerate-resolution maging Spectroradiometer (MODIS) aerosol optical depth data sets. Using a 355 nm extinction coefficient profile solved from the lidar MODIS AOD (aerosol optical depth) is scaled down to the surface to generate a regional composite depiction of surface visibility. These results demonstrate the potential for applying passive satellite depictions of broad-scale aerosol optical properties together with a ground-based surface lidar and zenith-viewing sun photometer for improving quantitative assessments of visibility in a city such as Hong Kong.
近年来，由于该地区社会经济的快速发展导致空气污染，香港的地表能见度有所下降。除了健康标准恶化之外，能见度降低还会扰乱日常的民用和公共作业，对交通运输和航空业的影响尤为显著。利用现有的地面和卫星气溶胶光学特性和垂直分布估算值来解决区域能见度问题，可能比单纯依靠少数现有的地面能见度监测站更有效。先前的研究表明，尽管这些传感器没有考虑到解决相关参数所需的范围分辨信息和间接参数化，但卫星测量与近地表光学特性相关性很好。通过将这种分析扩展到包括自主地面激光雷达仪器的垂直分辨气溶胶廓线信息，这项工作开发了六个模型，用于自动评估地表能见度。利用地面激光雷达、太阳光度计能见度计和中分辨率成像光谱仪（MODIS）气溶胶光学厚度数据集来估算区域能见度。利用激光雷达 MODIS AOD（气溶胶光学厚度）求解的 355nm 消光系数廓线向下扩展到地表，以生成区域复合地表能见度图。这些结果表明，有潜力将被动卫星对大尺度气溶胶光学特性的描述与地面表面激光雷达和天顶观测太阳光度计结合起来，以提高对香港等城市的能见度进行定量评估。
