Calibrating a ground-based backscatter lidar for continuous measurements of PM2.5
Calibrating a ground-based backscatter lidar for continuous measurements of PM2.5
复制标题
校准地面反向散射激光雷达以连续测量 PM2.5
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Oderbolz
中科院分区：
文献类型：
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作者：
M. Pesch;D. Oderbolz
大气研究和空气质量控制的主要问题之一是大气中有害颗粒物（PM）的减少。小颗粒可以进入人体呼吸道，导致严重的健康问题，如慢性阻塞性肺疾病（COPD）、哮喘甚至肺癌。最近，人们的兴趣已从PM10转向颗粒物质的更细组分，例如PM2.5，因为人们认为更细颗粒对健康的影响更为严重。到目前为止，颗粒物的测量主要是在地面进行的。然而，重要的大气过程，即粒子的形成、输送和垂直混合过程，主要发生在行星边界层的高海拔地区。原则上，激光雷达提供了观察这些过程发生的能力。本文概述的新方法展示了在独立操作中使用小型且相当便宜的激光雷达来研究颗粒物，特别是PM2.5的传输过程。作为参考，PM2.5的连续测量是通过安装在柏林北部（Frohnauer Turm）海拔325米的一座塔上的传统原位监测仪获得的。这些PM2.5测量值将与从大约100公里处采集的后向散射激光雷达数据（1064纳米）进行比较。距离地面60米，高度15公里，空间分辨率为15米。325 m处的垂直后向散射剖面将与塔上的pmm2,5监测仪获得的浓度相关。这两种测量都有180秒的时间分辨率，以观察在短时间尺度上发生的过程。目的是从后向散射激光雷达数据中获得估算PM2.5浓度的相关函数。这种校准的激光雷达系统是环境机构和大气研究小组观察和调查高水平PM浓度原因的宝贵工具。第一个结果显示，根据相对湿度的水平，具有相当好的线性相关性。
One of the main issues of atmospheric research and air quality control is the reduction of harmful particulate matter (PM) in the atmosphere. Small particles can enter the human airways and cause serious health problems such as COPD (Chronic Obstructive Pulmonary Disease), asthma or even lung cancer. Recently, interest has shifted from PM10 to finer fractions of particulate matter, e.g. PM2.5, because the health impact of finer particles is considered to be more severe. Up to now measurements of particulate matter were carried out mainly at ground level. However important atmospheric processes, i.e. particle formation, transport and vertical mixing processes, take place predominantly at higher altitudes in the planetary boundary layer. Lidar in principle provides the ability to observe these processes where they occur. The new method outlined in this paper demonstrates the use of a small sized and quite inexpensive lidar in stand-alone operation to investigate transport processes of particulate matter, and PM2.5 in particular. Continuous measurements of PM2.5 as a reference are gained with a conventional in-situ monitor, installed on a tower at an altitude of 325 m in the North of Berlin (Frohnauer Turm). These PM2.5 measurements will be compared with backscatter Lidar data (1064 nm) taken from approx. 60 m over ground up to an altitude of 15 km with a spatial resolution of 15 m. The vertical backscatter profiles at 325 m will be correlated to the concentrations obtained by the PM2,5 monitor on the tower. Both measurements have a time resolution of 180 s to observe also processes that take place at short time scales. The objective is to gain correlation functions for estimating PM2.5 concentrations from backscatter Lidar data. Such a calibrated Lidar system is a valuable instrument for environmental agencies and atmospheric research groups to observe and investigate causes of high level PM concentrations. First results show a reasonably good linear correlation depending on the level of the relative humidity.