RAPID: The GNSS Instrument System for Multistatic and Occultation Sensing (GISMOS) for Future Application to Precipitation Processes in Atmospheric River Events

RAPID：用于多基地和掩星传感 (GISMOS) 的 GNSS 仪器系统，用于未来应用于大气河流事件降水过程

• 批准号: 1454125
• 负责人: Jennifer Haase
• 金额: $ 6.82万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-11-15 至 2015-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1454125&HistoricalAwards=false
• 关键词: RAPID; GNSS; Instrument; System; Multistatic

Atmospheric rivers are responsible for bringing large quantities of moisture to the arctic, Pacific Northwest, and California coastlines, leading to heavy precipitation. It is not fully understood how the vertical distribution of moisture and aerosols affects precipitation processes, especially in terms of precipitation efficiency and the flux of moisture that reaches northern latitudes and is available for interaction with cold fronts. It would be advantageous to be able to use direct information on the vertical distribution of moisture and precipitation to investigate the sensitivity of the models to the physics parameterizations during this type of event. While the model tuning approach has in general been successful for the current climate, it is not necessarily expected that as climate changes, the same will be true. Therefore, to make simultaneous measurements of the large-scale vertical distribution of hydrometeors and moisture in these regions of high moisture flux to have a more reliable basis for predicting precipitation is crucial. Airborne measurements of moisture using GPS radio occultation can be used as a targeted method of observation to provide data to address this scientific question, in concert with other airborne and satellite observations.Recent simulations indicate the possibility of detecting the presence of large raindrops from forward scattering effects measured on left-hand circularly polarized (LHCP) GPS signals. If this can be shown to be feasible, then airborne GPS radio occultation measurements could not only provide refractivity profiles from normal RHCP signals, but also provide indications of the presence of heavy precipitation and precipitation rates from differential LHCP minus RHCP signals. As a first step in this direction, some preliminary measurements during heavy precipitation events will be made using the existing GISMOS instrument. A NASA DC-8 flight operation in October-November 2014 on flights from California to Chile, then transects across the Drake Passage will provide such an opportunity, which would test data collection with alternate antenna configurations, on the transect over the inter tropical convergence zone where heavy precipitation is likely. Flight tests during August 2014 would also provide a means for performing some needed maintenance on the GISMOS instrument, to prepare it for future work on missions dedicated to atmospheric river events, and for use by the larger NSF community.Intellectual Merit:The attempt to develop this original and innovative use of GISMOS for precipitation sensing simultaneously with moisture sensing with high vertical resolution will advance effective modeling of precipitation processes. The project will focus on the physical phenomenon of atmospheric rivers, an important process of moisture transport from the tropics to mid-latitudes.Broader Impacts:The refurbishing and preparation of the GISMOS instrumentation for continued use by the NSF community as part of the HIAPER suite of instrumentation enhances infrastructure for research by contributing to the Lower Atmospheric Observing Facility. The modifications make it possible to use the GPS/INS component of GISMOS separately from the GPS remote sensing components, and directly benefit any researcher using the GV aircraft by substantially increasing the accuracy over the existing instrumentation.

大气河流给北极、西北太平洋和加利福尼亚海岸线带来大量湿气，导致强降水。目前还不完全了解水分和气溶胶的垂直分布如何影响降水过程，特别是在降水效率和到达北纬地区并可与冷锋相互作用的水分通量方面。能够使用有关湿度和降水垂直分布的直接信息来研究模型对此类事件期间物理参数化的敏感性将是有利的。虽然模型调整方法对于当前气候总体来说是成功的，但随着气候变化，情况不一定会如此。因此，同步测量这些高湿通量区域的水凝物和水分的大范围垂直分布，为降水预测提供更可靠的依据至关重要。使用 GPS 无线电掩星进行机载湿度测量可作为一种有针对性的观测方法，与其他机载和卫星观测相结合，为解决这一科学问题提供数据。最近的模拟表明，可以通过左旋圆偏振 (LHCP) GPS 信号测量的前向散射效应来检测大雨滴的存在。 如果这被证明是可行的，那么机载 GPS 无线电掩星测量不仅可以提供正常 RHCP 信号的折射率剖面，还可以根据差分 LHCP 减去 RHCP 信号提供强降水存在和降水率的指示。作为朝这个方向迈出的第一步，将使用现有的 GISMOS 仪器在强降水事件期间进行一些初步测量。 2014 年 10 月至 11 月，美国国家航空航天局 (NASA) DC-8 飞行操作从加利福尼亚州飞往智利，然后横跨德雷克海峡的横断面将提供这样的机会，这将测试在可能有强降水的热带辐合带上的横断面上使用备用天线配置进行数据收集。 2014 年 8 月期间的飞行测试还将提供一种对 GISMOS 仪器进行一些必要维护的方法，为未来致力于大气河流事件的任务做好准备，并供更大的 NSF 社区使用。 智力优点：尝试开发 GISMOS 的这种原创和创新用途，同时进行高垂直分辨率的降水传感和湿度传感，这将促进降水过程的有效建模。该项目将重点关注大气河流的物理现象，这是水分从热带向中纬度地区输送的重要过程。 更广泛的影响：作为 HIAPER 仪器套件的一部分，翻新和准备 GISMOS 仪器供 NSF 社区继续使用，通过为低层大气观测设施做出贡献，增强了研究基础设施。这些修改使得可以将 GISMOS 的 GPS/INS 组件与 GPS 遥感组件分开使用，并通过大幅提高现有仪器的精度，直接使使用 GV 飞机的研究人员受益。