Development of a Gas Correlation Camera for Improved Ground-Based Monitoring of Volcanic SO2 Emissions

0321869沃森这笔赠款支持开发和现场测试的轻量级（约。3公斤）便携式气体相关照相机，用于测量火山气体羽流中的二氧化硫。 该照相机将以Apogee AP 8 P数码照相机为基础，配有1024 x 1024电荷耦合器件探测器，配备100 mm焦距透镜和带通滤光片，以选择具有强二氧化硫吸收带（318 nm）波长的紫外线辐射，并且保持在铝外壳中，该铝外壳允许滤光轮机构通过透镜前面的具有已知浓度的SO2的气室。 通过已知SO2浓度的参考池和不含SO2的空白参考池拍摄的图像之间的差异与视线SO2负荷成比例。 CCD阵列的设计将有助于对大面积的羽流进行空间测绘，运行定制软件的相关现场膝上型计算机将允许对数据进行近实时的解释和可视化。 该仪器将在实验室进行校准，然后在蒙大拿州的一家燃煤电厂进行测试，该电厂独立记录烟囱排放物中的二氧化硫浓度。 这些测试将尝试验证实验室校准并评估仪器的检测限。 典型的燃煤发电厂排出物具有通常比典型的火山气体小一个数量级的SO2通量（例如，分别为25-100吨/日和200-1000吨/日）。 该仪器还将在蒙特塞拉特的活苏弗里埃山火山进行测试，那里已经有监测火山羽流中二氧化硫的独立技术（即，COSPEC和DOAS）。 在近实时的大气中准确地成像SO2的动态和准确地估计SO2通量的能力是火山学和大气化学研究的关键需求，也是工业环境监测的潜在有用工具。 该仪器的开发和测试将涉及密歇根理工大学的一名研究生和教师，并与美国航天局喷气推进实验室和蒙特塞拉特火山观测站的科学家合作。***

0321869WatsonThis grant supports the development and field testing of a lightweight (ca. 3 kg.) portable gas correlation camera for the measurement of SO2 in volcanic gas plumes. The camera will be based on an Apogee AP8P digital camera with a 1024 x 1024 charge coupled device (CCD) detector, fitted with a 100 mm focal length lens and bandpass filter to select for UV radiation at a wavelength that has a strong SO2 absorption band (318 nm), ad maintained in an aluminum housing which would allow a filter wheel mechanism to pass gas cells with known concentrations of SO2 in front of the lens. The difference between an image shot through a reference cell of know SO2 concentration and a blank reference cell with no SO2 is proportional to the line-of-sight SO2 burden. The CCD array design will facilitate spatial mapping of large areas of plumes and an associated field laptop running customized software will allow for near real-time interpretation and visualization of the data. The instrument will be laboratory calibrated and then tested at a coal-fired power plant in Montana that independently records SO2 concentrations in their smokestack effluent. These tests will attempt to validate laboratory calibrations and asses the detection limits of the instrument. Typical coal-fired power plant effluents have SO2 fluxes that are often an order of magnitude less than typical volcanic gases (e.g., 25-100 tonnes/d vs. 200-1000 tonnes/d, respectively). The instrument will also be tested at the active Soufriere Hills volcano on Montserrat where independent techniques for monitoring SO2 in the volcanic plume already exist (i.e., COSPEC and DOAS). The ability to accurately image the dynamics of SO2 in the atmosphere in near real-time and to accurately estimate SO2 fluxes is a critical need in volcanological and atmospheric chemistry research and a potentially useful tool in industrial environmental monitoring. The development and testing of this instrument will involve a graduate student and faculty at Michigan Technological University and collaborations with scientists at NASA-JPL and the Montserrat Volcanological Observatory. ***