黑碳气溶胶光吸收的吸湿增长特性测量新方法研究

Black Carbon (BC) is the main light-absorbing component of atmospheric aerosols. BC-containing particles take up water and grow larger in size after undergoing atmospheric aging processes, leading to significantly increase in their light absorption. Accurately measure hygroscopic enhancement characteristic of BC light absorption (f(RH)abs) is of great significance to accurately evaluate BC radiative forcing. However, the existing methods have large measurement uncertainty of f(RH)abs. Thus, there is an urgent need to develop an accurate and reliable measurement system. In this proposal, a novel measurement method of f(RH)abs is developed based on our established cavity-enhanced albedometer technique. The humidified cavity-enhanced albedometer allows simultaneous in-situ measurement of aerosol extinction and scattering coefficients, which provides an valuable approach for accurate measurement of f(RH)abs. The instrument development and its application will provide a significant approach for accurate assessment of BC radiative forcing, and which will expand our knowledge of the effect of aerosol on atmospheric climate.

黑碳（BC）是大气气溶胶中主要的吸收体，老化后的BC吸湿增长导致其光吸收特性显著增强，准确测量BC光吸收的吸湿增长特性对于BC辐射强迫的准确评估具有重要的意义。然而，现有方法测量误差大，迫切需要发展准确可靠的测量系统。本项目基于我们发展的腔增强反照率技术，建立新型的气溶胶光吸收吸湿增长测量系统。通过消光和散射系数的原位同步测量，实现气溶胶光吸收吸湿增长因子的准确测量，并应用于实验室和实际大气BC光吸收的吸湿增长特性测量研究。项目的开展将为准确评估BC辐射强迫提供重要的测量手段，从而提升气溶胶气候效应科学问题认知的水平。

准确测量气溶胶光吸收的吸湿增长特性对于黑碳气溶胶辐射强迫的准确评估具有重要的意义。然而，现有方法只能单独测量消光或散射吸湿增长特性，难以准确获取气溶胶光吸收的吸湿增长特性。本项目将腔增强反照率光谱仪与湿度快速调节系统相结合，发展了一种新型的气溶胶光学吸湿增长特性测量装置。该系统能实现气溶胶消光、散射、吸收和单次散射反照率的吸湿增长因子的同步测量，并能快速获得相应的吸湿增长曲线。测量结果表明该装置为气溶胶吸湿性研究，尤其是吸收性气溶胶吸湿性研究提供了一种关键技术手段。此外，该装置参加了第二次青藏高原综合科学考察研究试验，首次获得了林芝和拉萨市地区的气溶胶多光学参数吸湿增长特性的数据。与现有方法相比，该技术不仅光学参数齐全、准确可靠，而且造价成本低、稳定性好、适用于台站长期观测，有很好的科研和业务应用前景。