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.php

2011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）在坦巴拉姆巴湿润桉树林超级观测点布设了一台宇宙射线土壤水分传感器。CosmOz仅是全球不断壮大的同类监测网络集群中的一员，目前美国、德国、英国均已搭建相关网络，南美、非洲与欧洲的诸多项目也在采用该项技术。
此类传感器借助源自外太空的宇宙射线，可对面积约40公顷、深度达90厘米的区域内的土壤平均湿度进行监测。系统通过测量宇宙射线与大气及土壤表层数米介质相互作用产生的快中子完成监测：土壤中的水分子会大幅减缓此类中子的运动速率，因此单位时段内测得的中子计数与土壤含水量呈反比关系。为估算体积含水量，每套系统均需按照标准规程，采集干湿两种湿度状态下的土壤样本开展校准。
数据采集间隔为60分钟，并上传至由亚利桑那大学运维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促成了数据托管协议，如今该协议已推动建成一个持续扩容的国际数据门户，用于分发和处理宇宙射线探测仪采集的数据。
坦巴拉姆巴超级观测点的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红色暗沃土（dermosol），厚度3至4米。
坦巴拉姆巴观测点的数据可从http://cosmos.hwr.arizona.edu/Probes/StationDat/077/index.php 下载。