Collaborative Research: Spatial Averaging of Oceanic Rainfall Variability using Underwater Sound

机构：Nystuen/UW提案编号：OCE-0241245PI/机构：Anagnostou/UConn提案编号：OCE-0241552PI/机构：Amitai/UMBC提案编号：OCE-0241186降雨固有的时空变异性使降雨成为最难测量的地球物理量之一，但它也是最重要的。声学雨量计(ARG)通过监听雨水撞击海洋表面产生的水下声音信号来探测和测量降雨率，可以在海洋地区提供这些数据。然而，声学雨量测量有几个特点还没有得到充分的探索。这些包括降雨信号与部署深度的固有空间平均、测量海洋环境中的水滴大小分布的能力以及测量的高时间分辨率。我们建议通过在放置在深水(2公里)但在高分辨率X波段极化(X-POL)沿海天气雷达(不到40公里)范围内的系泊设备上部署几个垂直分离的ARG来检查与ARG相关的固有空间平均。还将在雷达40公里范围内安装一个密集(约20个规格)的雨量计网，以提供对雷达数据的对比验证。将在较近的距离(~5公里)安装一个二维视频视盘测量仪，用于开发极化算法和评估X-POL测量。X-POL雨量估计将用于验证水滴大小分布的声学测量以及随后的降雨类型分类。水听器上的降雨量的空间分布将被用来预测接收到的声信号作为深度的函数。拟议的实地试验将首次允许使用高分辨率雷达对水下声学降雨测量进行全面调查，从而能够审查用于遥感(雷达和卫星)降雨量估计的声学测量的深水(公海和海洋)验证潜力。确认海洋降雨量测量是气候研究和气候变化的可预测性及其对人类社会的影响的一个重要组成部分。这将是3所大学和雅典国家天文台(希腊)之间的合作努力，从而建设全球科学和工程基础设施。人力资源开发将包括学生参与实地测量和相关研究。

ABSTRACTPI/Institution: Nystuen / UW Proposal No: OCE-0241245PI/Institution: Anagnostou / UConn Proposal No: OCE-0241552PI/Institution: Amitai / UMBC Proposal No: OCE-0241186The inherent spatial and temporal variability of rainfall makes rain one of the most difficult geophysical quantities to measure anywhere, and yet it is one of the most important. Acoustic rain gauges (ARGs), which detect and measure rainfall rate by listening for the underwater sound signal generated by rain striking the ocean surface, can provide these data in oceanic regions. However, there are several features of the acoustic rainfall measurement that have not been fully explored. These include the inherent spatial averaging of the rainfall signal with depth of deployment, the ability to measure drop size distribution in the oceanic environment, and the high temporal resolution of the measurement. We propose to examine the inherent spatial averaging associated with ARGs by deploying several vertically separated ARGs on a mooring placed in deep water (2 km), but within range of a high-resolution X-band polarimetric (X-POL) coastal weather radar (less than 40 km). A dense (~20 gauges) rain gauge network will also be installed within a 40 km range of the radar to provide a comparison validation of the radar data. A two-dimensional video disdrometer will be installed at closer range (~5 km) to be used for polarimetric algorithm development and evaluation of the X-POL measurements. The X-POL rain estimates will be used to validate the acoustic measurement of drop size distribution and the subsequent classification of rainfall type. The spatial distribution of rainfall over the hydrophones will be used to predict the received acoustic signal as a function of depth. The proposed field experiment will permit for the first time a comprehensive investigation of underwater acoustic rainfall measurements with a high-resolution radar, thus allowing an examination of the deep-water (open sea and oceans) validation potential of acoustic measurements for remote sensing (radar and satellite) rainfall estimates. Validation of oceanic rainfall measurements is an important component of climate research and the predictability of climate change with its subsequent impact on human societies. This will be a collaborative effort between 3 universities and the National Observatory of Athens (Greece), thus building global science and engineering infrastructure. Human resource development will include student participation in both field measurements and associated research.