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

首席调查员(PI)将进行必要的光谱研究和校准，以便对2008年春季在国家科学基金会(NSF)G-V研究飞机上进行的START(平流层-对流层区域传输分析)08/PreHIPPO外业活动中的垂直腔面发射激光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的探测精度和最低检测下限都是最好的。从气候、化学和动力学角度来看，水蒸气是对流层顶区域最重要的微量气体物种，准确的测量对于评估START08/PreHIPPO的科学目标至关重要。这些研究将通过利用VCSEL湿度计的小尺寸的新型恒温、相变、有机泥浴来进行。在实验室和国际水蒸气仪器比对研究中的初步研究表明，这种校准方法是准确的，最大限度地减少了其他校准技术中常见的残留水蒸气和放气。该项目的目标是为START08/PreHIPPO提供一个质量控制的数据集，并为2009年1月的河马(HIAPER极地对极地观测)准备仪器，该仪器可供国际空间局和科学小组中的其他人用来研究对流层顶区域的化学、动力学和微物理特性。VCSEL数据集与其他湿度计、痕量气体物种和模拟分析的其他测量相结合，将有助于理解全球气候变化和大气动力学。这项工作将涉及一名REU(本科生研究经验)学生在2008年夏天进行实验室研究和数据分析，而另一名本科生很有可能在2008-2009学年兼职参与这一项目。此外，还将有一名女研究生参与2008-2009学年这一数据的分析。

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.