RAPID: Airborne Campaign for Imaging Polar Mesospheric Clouds During the Deep Solar Minimum

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该项目旨在首次对极地中间层云进行空中观测。建议在大约6月25日至7月21日期间开展一次运动，预计这一期间极地中间层云的出现频率将达到高峰。大约25架Mooney M20K研究飞机将从加拿大阿尔伯塔省的High Level机场起飞，飞行高度接近23,000英尺，大约在午夜前90分钟开始观测。飞机仪表由CCD成像仪组成，在可见光和红外波长下工作，将获得许多小时和广泛区域的观测结果。由于飞机将在对流层上空飞行，成像仪将能够获得长时间内不间断的极地中间层云连续成像，提供一系列独特的图像，捕捉云的时间演变。在每次飞行期间，将预测“中间层冰航空”（AIM）卫星的准确飞越时间，如有可能，将使用机载成像仪和AIM上向下看的CIPS相机进行普通体积观测。空中测量提供极地中间层云的连续成像，卫星测量提供广泛的极地覆盖范围，这种互补性质将使人们能够第一次详细研究云的演变。就目前的太阳活动状况而言，这次活动的时机尤其值得注意，它的特点是近代历史上最深的太阳活动极小期；预计夏季中间层将异常寒冷。云的出现频率在太阳极小期结束时达到最大值，在此期间云常向低纬度地区延伸。由于观测的频率高度依赖于季节相对于夏至的天数，因此也可以获得关于极地中间层云随季节变化的一些信息。该项目有几个更广泛的影响。这项研究对学生完成博士论文至关重要。与NASA AIM卫星进行的协调观测将改善对二维极地中间层云结构和行为的描绘。据推测，极地中间层云对高层大气的全球变化很敏感，所获得的观测结果将为现有的云数据库提供独特的补充。该项目代表了一个概念验证实验，可能有利于未来活动的设计和执行。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This project aims to make the first airborne observations of polar mesospheric clouds. A campaign is proposed from approximately 25 June to 21 July, coinciding with the period when the occurrence frequency of polar mesospheric clouds is expected to peak. About 25 flights of a Mooney M20K research aircraft will be flown from High Level Airport in Alberta, Canada, at altitudes near 23,000 feet with observations commencing approximately 90 minutes before midnight. The aircraft instrumentation consists of CCD imagers operating at visible and IR wavelengths that will obtain observations over many hours and over an extensive region. Since the aircraft will fly above the tropospheric weather, the imagers will be able to obtain uninterrupted sequential imaging of polar mesospheric clouds over long time periods, providing a unique series of images that will capture the temporal evolution of the clouds. During each flight, the exact overpass time of the Aeronomy of Ice in the Mesosphere (AIM) satellite will be predicted and, if possible, common volume observations will be taken with the airborne imagers and with the downward-looking CIPS camera on AIM. The complementary nature of airborne measurements, providing continuous imaging of polar mesosphere cloud, with satellite measurements, providing extensive polar coverage, would enable the first detailed study of the evolution of the clouds. The timing of the campaign is especially noteworthy in term of the current solar conditions, which features the deepest solar minimum in recent history; an exceptionally cold summer mesosphere is expected. The cloud occurrence frequency is a maximum near the end of solar minimum, during which the clouds often extend to lower latitudes. Some information on the variability of polar mesospheric clouds with season may also be obtained, since the frequency of observation is highly dependent on the day of the season relative to the summer solstice. There are several broader impacts to the project. The research is central to the completion of a student Ph.D. thesis. The coordinated observations made with the NASA AIM satellite will lead to improved delineation of the 2-D polar mesospheric cloud structure and behavior. Polar mesospheric clouds have been hypothesized to be sensitive to global change in the upper atmosphere and the observations obtained would provide a unique complement to the existing cloud database. The project represents a proof-of-concept experiment which may benefit the design and execution of future campaigns.