Soil Moisture, Cosmic Ray Soil Moisture Sensor, Tumbarumba Wet Eucalypt SuperSite, 2011-2014

A cosmic ray soil moisture sensor was installed at the Tumbarumba Wet Eucalypt Supersite on 03 Apr 2011 by the Australian Cosmic Ray Soil Moisture Monitoring Network (CosmOz; http://www.ermt.csiro.au/html/cosmoz.html). CosmOz represents just one of a growing number of networks around the World. Other networks are found in USA, Germany, and the UK with other projects adopting the technology in South America, Africa and Europe. These sensors use cosmic rays originating from outer space to measure average soil moisture over an area of about 40 hectares to a depth up to 90 cm. The system measures fast neutrons that are produced from interactions of cosmic rays with the atmosphere and top few meters of soil. The intensity of these neutrons are moderated largely by water molecules in the soil. The number of neutrons counted over a period of time is inversely proportional to the amount of water in the soil. To estimate volumetric water content, each system is calibrated against soil samples that are collected from dry and wet moisture regimes using a standard protocol. Data is collected every 60 min and uploaded to data portal infrastructure which is maintained by the University of Arizona. This infrastructure and associated web interface were established as part of the US based Cosmic-ray Soil Moisture Observation System (COSMOS, http://cosmos.hwr.arizona.edu/). Collaboration between Australian and US researchers has facilitated a data hosting agreement which has now resulted in a growing international data portal for delivering and processing data from cosmic-ray probes. Tumbarumba Supersite land cover: Wet sclerophyll eucalyptus forest, Land use: native/plantation forestry, Soil type: Acidic, eutrophic red dermosol, 3 - 4 m deep Tumbarumba data can be downloaded from http://cosmos.hwr.arizona.edu/Probes/StationDat/077/index.php2011年4月3日，澳大利亚宇宙射线土壤湿度监测网络（CosmOz，http://www.ermt.csiro.au/html/cosmoz.html）于Tumbarumba湿地桉树林超级观测站部署了一台宇宙射线土壤水分传感器。CosmOz仅是全球日益壮大的同类监测网络之一，美国、德国、英国均已建成此类网络，南美、非洲与欧洲的诸多项目也已应用该技术。 此类传感器依托源自外太空的宇宙射线，可对面积约40公顷、深度达90厘米的土壤平均含水率进行监测。系统通过探测宇宙射线与大气及表层数米土壤相互作用产生的快中子完成监测：土壤中的水分子会极大程度地减缓这些中子的运动速率，单位时段内的中子计数与土壤含水量呈反比关系。为估算体积含水率，每套系统均需依照标准规程，采集干湿两种湿度状态下的土壤样本开展标定工作。 数据采集间隔为60分钟，采集后上传至由亚利桑那大学维护的数据门户基础设施。该基础设施及配套网页界面是美国宇宙射线土壤湿度观测系统（COSMOS，http://cosmos.hwr.arizona.edu/）的组成部分。澳美两国研究人员的合作推动达成了数据托管协议，如今该协议已助力建成一个不断扩容的国际数据门户，用于发布和处理来自宇宙射线探测仪的相关数据。 Tumbarumba超级观测站相关参数如下：土地覆被为湿润硬叶桉树林，土地利用类型为原生林/人工林，土壤类型为酸性富营养型红色暗色土（red dermosol），厚度3~4米。 可通过http://cosmos.hwr.arizona.edu/Probes/StationDat/077/index.php下载Tumbarumba超级观测站的相关数据。