SGER: Water Vapor Measurements from the G-V VCSEL Hygrometer during START08/PreHIPPO

首席研究员（PI）将进行必要的光谱研究和校准，对2008年春季在美国国家科学基金会（NSF） G-V研究飞机上进行的START（平流层-对流层区域运输分析）08/PreHIPPO野外活动中获得的垂直腔面发射激光（VCSEL）水蒸气数据进行后处理。在NSF G-V上的所有水汽仪器中，VCSEL湿度计在对流层上层和平流层下层条件下具有最佳的精度和最低的探测限。从气候、化学和动力学的角度来看，水蒸气是对流层顶区域最重要的微量气体，准确的测量对于评估START08/PreHIPPO科学目标至关重要。这些研究将通过使用新的恒温，相变，有机泥浆浴，利用VCSEL湿度计的小尺寸进行。在实验室进行的初步研究和国际水蒸汽仪器比对研究表明，这种校准方法是准确的，并最大限度地减少了其他校准技术中常见的残余水蒸气和放气。该项目的目标是为START08/PreHIPPO提供一个有质量控制的数据集，并为2009年1月的HIPPO （HIAPER极对极观测）准备仪器，该仪器可以被PI和科学小组的其他成员用来研究对流层顶区域的化学、动态和微物理特性。VCSEL数据集，当与其他湿度计的其他测量、微量气体种类和建模分析相结合时，将有助于了解全球气候变化和大气动力学。这项工作将在2008年夏季由一名本科生进行实验室研究和数据分析，并且很有可能在2008-2009学年有另一名本科生兼职参与该项目。此外，一名女研究生也将在2008-2009学年参与对这些数据的分析。

The Principal Investigator (PI) will conduct the necessary spectroscopic studies and calibrations to post-process the vertical-cavity surface-emitting laser (VCSEL) water vapor data from the START(Stratosphere-Troposphere Analyses of Regional Transport)08/PreHIPPO field campaign that took place in spring 2008 onboard the National Science Foundation (NSF) G-V research aircraft. The VCSEL hygrometer shows the best precision and lowest limit of detection in upper tropospheric and lower stratospheric conditions of all the water vapor instruments onboard the NSF G-V. Water vapor is the most important trace gas species in the tropopause region from climate, chemistry, and dynamics perspectives, and accurate measurements will be critical towards assessing the START08/PreHIPPO science objectives. These studies will occur through the use of novel constant-temperature, phase-change, organic slush baths which exploit the small size of the VCSEL hygrometer. Initial studies in the laboratory and at an international water vapor instrument intercomparison study showed that this method of calibration is accurate and minimizes residual water vapor and outgassing common in other calibration techniques. The goal of this project is to provide a quality-controlled dataset for START08/PreHIPPO and to prepare the instrument for HIPPO (HIAPER Pole-to-Pole Observations) in January 2009 that can be used by the PI and others in the Science Team to address chemical, dynamic, and microphysical properties of the tropopause region. The VCSEL dataset, when combined with other measurements from other hygrometers, trace gas species, and modeling analyses, will help in the understanding of global climate change and atmospheric dynamics. The work will involve one REU (Research Experience for Undergraduates) student in the laboratory studies and data analysis during the summer of 2008, and there is a strong likelihood of another undergraduate student working on this project part-time in the 2008-2009 school year. In addition, one female graduate student will also be involved in the analysis of this data during the 2008-2009 academic year.