Sensitive and Versatile Tropospheric Hydrogen Chloride (HCl) Instrument

灵敏且多功能的对流层氯化氢 (HCl) 仪器

• 批准号: 0948015
• 负责人: Azer Yalin
• 金额: $ 21.91万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0948015&HistoricalAwards=false
• 关键词: Sensitive; Versatile; Tropospheric; Hydrogen; Chloride

Hydrogen chloride (HCl) gas is key to the understanding of tropospheric halogen cycles, since it is a relatively abundant gas-phase halogen species that serves as a source, an intermediate, or an end product in the chemistry of more reactive chlorine compounds. It is, however, greatly undersampled in the troposphere. Accurate in situ measurements of HCl are critically needed to better quantify its sources, sinks, transport, and ultimately to better understand the processes that govern tropospheric halogen activation. This project will develop an ultra-sensitive optical sensor for HCl gas. The sensor is based on cavity ring-down spectroscopy (CRDS), a method for high-sensitivity optical absorption. Recent advances in optical spectroscopy make possible the development of a versatile (i.e., small, lightweight, low power consumption), accurate and specific HCl sensor with high sensitivity and time response. The HCl sensor will employ a near-infrared diode laser for continuous-wave CRDS. Although the sensor is primarily targeted at HCl detection, it will allow simultaneous methane detection with high sensitivity and precision. The development of such an instrument will facilitate studies of the atmospheric role of HCl and may enable deployment on mobile platforms, such as ships and aircraft.Improved understanding of halogen activation in general, and HCl in particular, has broad implications for modeling of both regional air quality and climate. Within polluted coastal environments, HCl is a primary product in acid displacement reactions with sea salt and is a key source for atomic chlorine. Halogen activation cycles involving HCl may also influence the climate system through the oxidation of methane and other organic gases, conversion of marine sulfur emissions to sulfate aerosol, and, potentially, regulation of tropospheric ozone and other oxidant levels. In terms of future instrumentation, the sensor design and architecture proposed here will provide a blueprint for development of similar sensors for other species relevant to atmospheric chemistry (e.g., acetylene, ammonia). The project will also provide unique educational opportunities for graduate and undergraduate students in mechanical engineering at Colorado State University (CSU). Particular efforts will be made to recruit women students and students from underrepresented groups to participate in the project. The students will design and develop a state-of-the-art instrument for atmospheric sensing and will interact with researchers in atmospheric chemistry at CSU, from other universities, and from nearby federal environmental research laboratories. Results of the research will be incorporated into courses at CSU, and disseminated at academic conferences.

氯化氢(HCl)气体是理解对流层卤素循环的关键，因为它是一种相对丰富的气相卤素物种，在更多活性氯化合物的化学中充当源、中间体或最终产物。然而，它在对流层中的采样严重不足。为了更好地量化其来源、汇、输送，并最终更好地了解支配对流层卤素激活的过程，迫切需要对HCl进行准确的现场测量。该项目将开发一种用于HCl气体的超灵敏光学传感器。该传感器基于腔衰荡光谱(CRDS)，这是一种高灵敏度的光吸收方法。光学光谱学的最新进展使得开发一种通用性强(即小、轻、低功耗)、高灵敏度和高时间响应的准确、特异的HCl传感器成为可能。HCl传感器将使用近红外半导体激光器进行连续波CRDS。虽然该传感器主要用于HCl检测，但它将允许同时进行高灵敏度和高精度的甲烷检测。这种仪器的开发将有助于研究HCl的大气作用，并可能使其能够部署在移动平台上，如船舶和飞机。更好地理解一般的卤素活化，特别是HCl，对区域空气质量和气候的模拟具有广泛的影响。在受污染的沿海环境中，HCl是与海盐进行酸置换反应的主要产物，也是原子氯的关键来源。涉及HCl的卤素活化循环还可能通过甲烷和其他有机气体的氧化、海洋硫排放转化为硫酸盐气溶胶以及可能调节对流层臭氧和其他氧化剂水平来影响气候系统。在未来的仪器方面，这里提出的传感器设计和结构将为开发与大气化学有关的其他物种(如乙炔、氨)的类似传感器提供蓝图。该项目还将为科罗拉多州立大学(CSU)机械工程专业的研究生和本科生提供独特的教育机会。将特别努力招募女学生和代表人数不足的群体的学生参加该项目。这些学生将设计和开发一种最先进的大气传感仪器，并将与CSU、其他大学和附近联邦环境研究实验室的大气化学研究人员进行互动。研究结果将被纳入CSU的课程，并在学术会议上传播。