Development of Atmospheric Chemistry Instrumentation

这个由四部分组成的研究项目旨在提高测量地面和大气之间大气物种通量的能力。部分由丹佛大学开发的检测系统将进一步开发和研究其确定这些通量的能力。第1部分。长径紫外（LPUV）光谱将与长径红外（LPIR）光谱相结合，用于测定各种物质的通量。将尝试两种新的系统方法。两者都利用了这样一个事实，即现代基于角立方的FTIR系统具有两个光输入端口，并且系统本质上响应于两者之间的强度差。梯度通量测量法可以利用这种直接测量物种梯度的能力，其灵敏度依赖于测量微小差异。来自同一光源的两束光将被设计成在两个不同的高度穿过路径，然后在FTIR中组合以进行差值测量。同一系统的另一种配置将发送两束围绕可疑发射源的两侧。这将实现自动减去除可疑源以外的所有排放。FTIR可以从以前的支持中获得，但是，望远镜、反射镜、软件、实验协议等将在该计划下开发。长期目标是更可靠地测量大气物种的排放和沉积。第2部分。一个可用的快速响应，原位，总硫监测仪将优化响应速度和灵敏度。它将通过涡流相关技术用于通量研究。其中一些通量研究将与国家大气研究中心（NCAR）大气表面湍流交换研究（ASTER）设施合作进行。第3部分。一种大气压、流动系统、自由基检测器已被开发出来，并被证明对氢过氧（HO2）和有机过氧（RO2）自由基的浓度有响应。这种装置，被称为PERCA（过氧化自由基检测器使用化学扩增），也被证明对许多碳氢化合物和含氧碳氢化合物的过氧化自由基有反应，最高可达C8。在这部分计划下进行的研究是研究干扰和开发便携式校准系统，用于制备含有已知浓度自由基的标准。第4部分。大气氯光化学在海洋地区的潜力已经成为一个有趣的科学争论的主题。这些研究人员将开发一种高灵敏度的系统来检测原子氯，从而有可能检测到氯光化学发生时可能形成的卤素胺的痕迹。

9417061 Stedman This four part research project is designed to improve the ability to measure the flux of atmospheric species between the ground and the atmosphere. Detection systems developed, in part, at the University of Denver, will be further developed and investigated in terms of their ability to determine these fluxes. Part 1. Long-path UV (LPUV) spectroscopy will be coupled with long-path IR (LPIR) spectroscopy and used to determine the fluxes of various species. Two new system approaches will be attempted. Both make use of the fact that modern corner-cube based FTIR systems have two input ports for light, and the system responds intrinsically to the intensity difference between the two. The gradient method for flux measurement, which depends on the measurement of small differences for its sensitivity, can make use of this ability to directly measure species gradients. Two light beams from the same source will be designed to traverse the path at two different altitudes to be combined in the FTIR for the difference measurement. Another configuration of the same system will send the two beams around two sides of a suspected emission source. This should achieve automatic subtraction of all but emissions from the suspect source. The FTIR is available from previous support, however, the telescopes, mirrors, software, experimental protocols, etc. will be developed under this program. The long-term goal is more reliable measurements of emission and deposition of atmospheric species. Part 2. An available fast-response, in-situ, total sulfur monitor will be optimized for response speed and sensitivity. It will be used for flux studies by means of the eddy-correlation technique. Some of the flux studies will be carried out in collaboration with the National Center for Atmospheric Research (NCAR) Atmosphere Surface Turbulence Exchange Research (ASTER) facility. Part 3. An atmospheric pressure, flow system, free radical dete ctor has been developed and shown to respond to concentrations of hydroperoxyl (HO2) and organic peroxyl (RO2) radicals. This apparatus, named PERCA (PEroxy Radical detector using Chemical Amplification) has also been shown to respond to a number of hydrocarbon and oxygenated hydrocarbon peroxy radicals up to C8. The research to be performed under this portion of the program is to study interferences and to develop a portable calibration system for preparing standards containing known concentrations of free radicals. Part 4. The potential for atmospheric chlorine photochemistry in oceanic regions has become the subject of an interesting scientific controversy. These researchers will develop a high- sensitivity system that will detect atomic chlorine, thus potentially detecting traces of halogen amines, which may be formed if chlorine photochemistry is taking place.