Soil water content in southern England derived from a cosmic‐ray soil moisture observing system – COSMOS‐UK          下载免费PDF全文

J. G. Evans  H. C. Ward  J. R. Blake  E. J. Hewitt  R. Morrison  M. Fry  L. A. Ball  L. C. Doughty  J. W. Libre  O. E. Hitt  D. Rylett  R. J. Ellis  A. C. Warwick  M. Brooks  M. A. Parkes  G. M. H. Wright  A. C. Singer  D. B. Boorman  A. Jenkins 《水文研究》2016,30(26):4987-4999

Cosmic‐ray soil moisture sensors have the advantage of a large measurement footprint (approximately 700 m in diameter) and are able to operate continuously to provide area‐averaged near‐surface (top 10–20 cm) volumetric soil moisture content at the field scale. This paper presents the application of this technique at four sites in southern England over almost 3 years. Results show the soil moisture response to contrasting climatic conditions during 2011–2014 and are the first such field‐scale measurements made in the UK. These four sites are prototype stations for a UK COsmic‐ray Soil Moisture Observing System, and particular consideration is given to sensor operating conditions in the UK. Comparison of these soil water content observations with the Joint UK Land Environment Simulator 10‐cm soil moisture layer shows that these data can be used to test and diagnose model performance and indicate the potential for assimilation of these data into hydro‐meteorological models. The application of these large‐area soil water content measurements to evaluate remotely sensed soil moisture products is also demonstrated. Numerous applications and the future development of a national COsmic‐ray Soil Moisture Observing System network are discussed. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Estimating snow water equivalent using cosmic-ray neutron sensors from the COSMOS-UK network     

John R. Wallbank  Steven J. Cole  Robert J. Moore  Seonaid R. Anderson  Edward J. Mellor 《水文研究》2021,35(5):e14048

The intensity of cosmic ray neutrons is inversely correlated with the amount of water present in the surrounding environment. This effect is already employed by around 50 neutron sensors in the COSMOS-UK network to provide daily estimates of soil moisture across the UK. Here, these same sensors are used to automatically provide estimates of snow water equivalent (SWE). Lying snow is typically ephemeral and of shallow depth for most parts of the UK. Moreover, soil moisture is usually high and variable, which acts to increase uncertainties in the SWE estimate. Nevertheless, even under such challenging conditions, both above ground and buried cosmic ray neutron sensors are still able to produce potentially useful SWE estimates. Triple collocation analysis suggests typical uncertainties of less than around 4 mm under UK snow conditions.  相似文献