基于光声光谱探测大气气溶胶光吸收新方法研究

Aerosol particles have a significant effect on the Earth's radiation balance, local or global climate and environmental chemistry, which significantly contribute to the uncertainties of radiative forcing. The magnitude of aerosol effects on climate or environmental chemistry strongly depends on the magnitude of light absorption by aerosols. However, currently, aerosol light absorption measurements still show large uncertainties, mainly because of the lack of appropriate instrumentation. Therefore, accurate measurement of aerosol light absorption is important in climate and environmental chemistry research, which is still a challenging task of high relevance..The photoacoustic (PA) technique is a direct method to measure light absorption, which is very suitable for measuring light absorption as it free from the influence of light scatter. Simultaneous measurement of aerosol light absorption measurements and nitrogen dioxide with photoacoustic spectroscopy will be carried out in the present proposal. The goal of the proposal is to resolve the problems that current aerosol light absorption measurements still show large uncertainties， and the signal of aerosol light absorption and nitrogen dioxide are still difficult to distinguish with traditional photoacoustic spectroscopy at blue light region. Meantime, the active atmospheric molecular of nitrogen dioxide is also detected simultaneously with high sensitivity. This is very important for climate and environmental chemistry research, as it will improve the accuracy of aerosol light absorption measurements and offer a new method for investigation the interaction between aerosol and nitrogen dioxide in atmosphere.

气溶胶在影响地球辐射能量平衡、局部气候、全球气候和大气环境化学中起着重要的作用，是造成目前辐射强迫参数不确定性的重要影响因素。气溶胶对气候、环境的作用程度强烈依赖于气溶胶的光吸收，然而，由于缺乏合适的技术方法，目前气溶胶光吸收的测量仍然带有很大的偏差。因此，准确测量气溶胶吸收的技术方法仍然是气候、环境化学研究中一个迫切的研究课题。.光声光谱是一种直接测量吸收的方法，不受光散射等因素的影响，很适合吸收的测量。为此，本申请拟开展基于光声光谱同时探测气溶胶光吸收和二氧化氮的新方法研究，解决目前气溶胶光吸收的测量准确度不高的问题，以及蓝光波段传统的光声光谱探测气溶胶光吸收时难于消除二氧化氮吸收干扰的技术难点,同时又可实现大气活跃分子二氧化氮的高灵敏度探测。这对气候和环境化学研究具有重要的科学意义，不仅将提高气溶胶光吸收测量的准确度，而且为大气气溶胶和二氧化氮相互作用的研究提供了新的技术方法。

本项目主要开展光声光谱测量气溶胶吸收的技术和方法研究,按照项目研究计划，首先开展了光声池的设计、光声池特性研究，并根据研究结果建立了适合气溶胶吸收测量的光声光谱实验系统，开展了光声光谱系统的标定和气溶胶光吸收特性测量的研究。然后，开展了实际大气气溶胶光吸收的连续观测实验研究。较好的完成了项目的预期研究内容，取得了一些有价值的研究成果，尤其是在国际上首次开创性的研究出了多通道光声光谱技术，为今后开展气溶胶吸收的波长依赖特征、吸收特征提供了技术手段。本项目研究期间，与项目相关的学术论文累计发表10篇，其中7篇为SCI收录期刊；会议论文5篇，其中国际会议3篇；申请专利4项，其中已授权2项。