获取大气颗粒物消光系数的差分吸收光谱法研究

发布时间：2018-03-30 13:36

本文选题：颗粒物　切入点：大气　出处：《光谱学与光谱分析》2017年06期

【摘要】：针对雾霾天气日益增多,大气污染气体向颗粒物的转化在加快,研究了一种大范围对其监测的差分吸收光谱方法。差分吸收光谱法可以实时、在线、准确同时获取颗粒物光学特性和大气痕量气体浓度。论文首先分析了双光路差分吸收光学遥感系统获取颗粒物绝对光强的原理,然后研究了基于单光路测量大气吸收谱,在干净天气状况下测量参考光谱,利用能见度数据,在550nm波段处实现系统校准,计算校准参数,从而获得大气绝对吸收光强,然后解析出大气总的消光系数。再从总的大气消光系数中,去除瑞利散射以及大气痕量气体吸收对消光系数影响后,精确解析出颗粒物消光系数。同时基于差分思想获取大气痕量气体的浓度。最后把该方法应用于外场实验,获取大气颗粒物在350~700nm波段范围内消光系数和大气中NO2的浓度。研究结果表明颗粒物消光系数的随着波长的增加而减少,符合Angstrom公式。该研究为分析大气气相/粒子非均相化学反应提供有力的技术支持。
[Abstract]:In view of the increasing weather of haze, the transformation of air pollution gas to particulate matter is speeding up, a differential absorption spectrum method is studied to monitor it in a large range.Differential absorption spectrometry (DAS) can obtain the optical properties of particulate matter and the concentration of trace gases in the atmosphere simultaneously in real time, online and accurately.This paper first analyzes the principle of obtaining absolute light intensity of particulate matter by dual optical path differential absorption optical remote sensing system, and then studies the measurement of atmospheric absorption spectrum based on single optical path, the measurement of reference spectrum in clean weather, and the use of visibility data.The system calibration is realized at the 550nm band and the calibration parameters are calculated so as to obtain the absolute absorption intensity of the atmosphere and then analyze the total extinction coefficient of the atmosphere.After removing the influence of Rayleigh scattering and atmospheric trace gas absorption on the extinction coefficient, the extinction coefficient of particulate matter can be accurately analyzed from the total atmospheric extinction coefficient.At the same time, the concentration of trace gases in the atmosphere is obtained based on the difference theory.Finally, the method is applied to the field experiments to obtain the extinction coefficient of atmospheric particulates in the range of 350~700nm band and the concentration of NO2 in the atmosphere.The results show that the extinction coefficient of particulate matter decreases with the increase of wavelength, which accords with the Angstrom formula.This study provides a powerful technical support for the analysis of atmospheric vapor / particle heterogeneous chemical reactions.
【作者单位】：淮北师范大学物理与电子信息学院;
【基金】：国家自然科学基金项目(41475017,41275027)资助
【分类号】：X513

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