Development of an Instrument for Multispectral Measurement of Aerosol Light Absorption

这是一项主要研究仪器奖，以支持发展一种仪器，以测量太阳光谱中不同波长的气溶胶颗粒的吸收。气溶胶吸收和散射太阳辐射，从而影响区域和全球气候。虽然缺乏关于气溶胶吸收光谱的准确数据，但现有证据表明，来自不同来源的气溶胶具有明显不同的光谱。例如，撒哈拉沙尘似乎在紫外光谱中吸收很强，但在可见光光谱中吸收很弱。另一方面，柴油烟灰在光谱上的吸收更为均匀。到目前为止，还没有仪器可以测量两个以上波长的气溶胶的原位吸收，尽管辐射传输计算需要的是吸收光谱的详细表示。因此，基于共振光声原理，将建立一个多波长单元，以测量从紫外到红外光谱的六个波长的吸收。通过测量（已知的）760纳米氧a波段的吸收来建立校准。该仪器将用于测量不同种类的自然和人为气溶胶的光谱吸收。这些信息对于理解人类使用燃烧对气候的影响至关重要。

This is a Major Research Instrumentation award to support the development of an instrument for measuring the absorption of aerosol particles at different wavelengths in the solar spectrum. Aerosols absorb and scatter solar radiation and thus influence regional and global climate. Though accurate data on aerosol absorption spectra are lacking, the available evidence indicates that aerosols from different sources have markedly different spectra. For example, Saharan dust appears to absorb strongly in the ultraviolet but weakly in the visible part of the spectrum. Diesel soot, on the other hand, absorbs more uniformly over the spectrum. To now, no instrument has been available to measure the in-situ absorption of aerosols at more than two wavelengths, though what is needed for radiative transfer calculations is a detailed representation of the absorption spectrum. Accordingly, a multi-wavelength unit will be built, based on the resonant photoacoustic principle, to measure the absorption at six wavelengths spanning the spectrum from the ultraviolet to the infrared. Calibration is established by measuring the (known) absorption of the 760-nm oxygen A-band. The instrument will be employed for measurements of the spectral absorption of different kinds of natural and anthropogenic aerosols. This information is essential for understanding the consequences of the human use of combustion on climate.