Development of Instrumentation to Measure Atmospheric Light Extinction and its Scattering and Absorption Components

在短波光学领域，缺乏足够的仪器阻碍了各种研究领域的科学进步。 大气中光的消光、散射和吸收的局部测量可应用于以下一些科学问题：1。 气溶胶辐射强迫及其对气候变化的影响. 使用主动或被动系统的光学遥感。 区域空气质量研究所需的大气能见度。首席研究员将开发能够测量大气总消光及其散射和吸收成分的仪器。该系统包括三个具体的仪器：（1）消光仪，它将几十公里的光路折叠成一米长的光腔，通过测量腔内光功率的指数衰减来确定消光。(2)一种新的散射仪器概念的基础上的反浊度计的概念，收集几乎所有的散射光，包括前向散射从大颗粒。(3)一种光吸收仪器，其通过利用光吸收的共振光声检测来产生光学光吸收的真实的实时原位测量。 全固态激光器的使用使该仪器比其前辈更紧凑，功耗更低。 创新的声学设计使该仪器比以前的设计灵敏一个数量级以上。拟议的这些文书的发展将产生一个文书组，比单独使用的三个文书有用得多。 例如，吸收和散射测量的组合可以确定单次散射气溶胶散射。 消光仪的加入将导致大气消光及其散射和吸收成分问题的实验关闭。 这种封闭对于质量保证的目的是极其重要的，即，通过检查测量的吸收和散射消光的总和是否等于测量的消光，可以直接评估测量精度。

In the shortwave optical regions, lack of adequate instrumentation hinders scientific progress across a variety of research areas. The local measurement of light extinction, scattering and absorption in the atmosphere has applications to a number of scientific problems related to:1. Aerosol radiative forcing and its influence on climate change.2. Optical remote sensing using either active or passive systems.3. Atmospheric visibility as needed for regional air quality studies.The Principal Investigators will develop instrumentation capable of measuring total atmospheric light extinction and its scattering and absorption components. The system to be developed includes three specific instruments:(1) An extinction instrument which folds several tens of kilometers of optical path into a one-meter length optical cavity and determines extinction by measuring the exponential decay of the optical power contained in the cavity. (2) A novel scattering instrument concept based on the inverse nephelometer concept which collects virtually all scattered light including the forward scattering from large particles. (3) A light absorption instrument which yields a real time in situ measurement of optical light absorption by utilizing resonant photoacoustic detection of light absorption. The use of an all-solid-state laser makes this instrument much more compact and less power hungry than its predecessors. Innovative acoustic design makes this instrument more than an order of magnitude more sensitive than previous designs. The proposed development of these instruments will result in an instrument cluster which will be far more useful than the three individual instruments used separately. For example, the combination of absorption and scattering measurements can determine the single-scattering aerosol albedo. Addition of the extinction instrument will result in experimental closure on the problem of atmospheric light extinction and its scattering and absorption components. This closure is extremely important for quality assurance purposes, i.e., measurement accuracy can directly be assessed by checking if the sum of measured absorption and scattering extinction equals the measured extinction.