Development, Deployment, and Validation of a Differential Abospbtion Lidar for Water Vapor Profiling in the Lower Troposphere

蒙大拿州立大学(MSU)的研究人员开发了一种新型的基于半导体激光的差分吸收激光雷达(DIAL)，用于对流层低层的水汽廓线。到目前为止，该仪器一直以实验室为基础，利用外腔二极管激光器和锥形半导体光放大器来生产可广泛调谐的DIAL激光发射器，能够访问许多不同强度的水蒸气线路。这是第一台基于半导体激光的Dial仪器，成功展示了夜间和白天的水蒸气剖面分析能力，并有可能带头以经济高效的方式部署类似设计的传感器网络。所支持的研究将测试和评价外地可部署刻度盘仪器的开发，以便在各种地理/气象环境中进行无人值守的长期数据收集。这种基于半导体激光的仪器包含了许多具有成本效益的现成组件，将进行改进，以在更宽的温度范围内运行。该仪器将部署在三个外地地点，以便在每个地点收集大约30天的数据。在这些实地部署期间收集的长期数据集将与现场水蒸气测量进行比较，以进行验证。这一努力的智力价值在于开发了一种更复杂、更具成本效益的DIAL仪器，可以部署在气候和天气研究和预报的地面网络中。这一努力的广泛影响包括改进对本地和中尺度天气影响(例如，雷暴发展)的监测和预报的潜在影响，这些影响高度依赖于对最接近地球表面的层中大气水汽含量的准确了解。与国家大气研究中心人员的密切合作将加快将开发的技术整合到国家科学基金会支持的研究人员可用的仪器套件中。通过直接参与这项工作，还将加强对研究生的培训。

Researchers at Montana State University (MSU) have developed a novel diode-laser-based differential absorption lidar (DIAL) for water vapor profiling in the lower troposphere. This instrument, which until now has been laboratory-based, utilizes external cavity diode lasers in conjunction with a tapered semiconductor optical amplifier to produce a widely tunable DIAL laser transmitter capable of accessing many water vapor lines of varying strength. This is the first diode-laser-based DIAL instrument to successfully demonstrate both nighttime and daytime water vapor profiling capabilities, and has the potential to spearhead cost-effective deployment of networks of similarly-designed sensors. The supported research will test and evaluate development of a field deployable DIAL instruments for unattended long-term data collection in a variety of geographic/meteorological settings. The semiconductor laser-based instrument, which incorporates many cost-effective off-the-shelf components, will be modified to operate over a wider temperature range. The instrument will be deployed at three field sites for data collection on the order of thirty days at each site. The long term data sets collected during these field deployments will be compared with in situ water vapor measurements for validation purposes. The intellectual merit of this effort rests is development of a more sophisticated and cost-effective DIAL instrument that can be deployed in a ground based network for climate and weather research and forecasting applications.Broader impacts of this effort include potential impacts of improved monitoring and forecasting of local and mesoscale weather effects (e.g., thunderstorm development) that are highly dependent on accurate knowledge of atmospheric water vapor content in the layer nearest the earth's surface. Close cooperation with personnel at the National Center for Atmospheric Research will speed integration of developed technologies into the suite of instruments available for NSF-supported researchers. Training of a graduate student will also be enhanced through direct involvement in this effort.