COSMOS: the COsmic-ray Soil Moisture Observing System

Zréda, Marek; Shuttleworth, W. James; Zeng, Xubin; Zweck, C.; Desilets, Darin; Franz, Trenton E.; Rosolem, Rafael

doi:10.5194/hess-16-4079-2012

Cited by 486 publications

(620 citation statements)

References 39 publications

(74 reference statements)

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“…A potential solution to fill the gap between point and remote sensing observations of soil moisture is the CRNP method, organized through the Cosmic-Ray Soil Moisture Observing System (COSMOS; Zreda et al, 2012), which has ∼ 200 probes operating globally since 2011. CRNP is a new and novel way to obtain high-resolution, semi-continuous soil moisture observations and, as a result, has the potential to advance LSM and irrigation parameterization development.…”

Section: Cosmic-ray Neutron Probementioning

confidence: 99%

Assessment of irrigation physics in a land surface modeling framework using non-traditional and human-practice datasets

Lawston

Santanello

Franz

et al. 2017

Hydrol. Earth Syst. Sci.

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Abstract. Irrigation increases soil moisture, which in turn controls water and energy fluxes from the land surface to the planetary boundary layer and determines plant stress and productivity. Therefore, developing a realistic representation of irrigation is critical to understanding land-atmosphere interactions in agricultural areas. Irrigation parameterizations are becoming more common in land surface models and are growing in sophistication, but there is difficulty in assessing the realism of these schemes, due to limited observations (e.g., soil moisture, evapotranspiration) and scant reporting of irrigation timing and quantity. This study uses the Noah land surface model run at high resolution within NASA's Land Information System to assess the physics of a sprinkler irrigation simulation scheme and model sensitivity to choice of irrigation intensity and greenness fraction datasets over a small, high-resolution domain in Nebraska. Differences between experiments are small at the interannual scale but become more apparent at seasonal and daily timescales. In addition, this study uses point and gridded soil moisture observations from fixed and roving cosmic-ray neutron probes and co-located human-practice data to evaluate the realism of irrigation amounts and soil moisture impacts simulated by the model. Results show that field-scale heterogeneity resulting from the individual actions of farmers is not captured by the model and the amount of irrigation applied by the model exceeds that applied at the two irrigated fields. However, the seasonal timing of irrigation and soil moisture contrasts between irrigated and non-irrigated areas are simulated well by the model. Overall, the results underscore the necessity of both high-quality meteorological forcing data and proper representation of irrigation for accurate simulation of water and energy states and fluxes over cropland.

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Section: Cosmic-ray Neutron Probementioning

confidence: 99%

Assessment of irrigation physics in a land surface modeling framework using non-traditional and human-practice datasets

Lawston

Santanello

Franz

et al. 2017

Hydrol. Earth Syst. Sci.

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“…Because SWC and soil temperature, air pressure and other factors vary over time, the raw neutron intensity should thus be corrected before SWC is calibrated. Fluctuations in atmospheric pressure, water vapor and solar activity are the main factors that affect the neutron intensity Zreda et al, 2012).…”

Section: Correction and Calibrationmentioning

confidence: 99%

“…Desilets and Zreda (2013) used diffusion theory and the neutron-transport model to derive an equation for estimating the footprint radius and analyzed the factors influencing the radius. Zreda et al (2012) systematically explained the principle, calculations, influencing factors, calibration and application of the CRNS to provide a better understanding for the wider application of this new approach. The correction of influencing factors has also received much attention.…”

Section: Introductionmentioning

confidence: 99%

Application of cosmic-ray neutron sensing to monitor soil water content in an alpine meadow ecosystem on the northern Tibetan Plateau

Zhu

Shao

Zeng

et al. 2016

Journal of Hydrology

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Keywords: CRNS Soil moisture Alpine meadow Tibetan Plateau s u m m a r y Cosmic-ray neutron sensing (CRNS) is a new method for continuously monitoring mean soil water content (SWC) on a hectometer scale. To evaluate the application and accuracy of the method for SWC observation in an alpine meadow ecosystem (AME), we installed the CRNS in a flat meadow near the Naqu prefecture on the northern Tibetan Plateau. We collecting soil samples and applying the system by the oven-drying method. A weather station was also installed near the CRNS for monitoring basic meteorological variables and the soil temperature and water content at various depths. Three Em-50 instruments for monitoring SWC and soil temperature were buried in three sub-quadrats northwest, northeast and southeast of the CRNS at distances of 460, 370 and 373 m, respectively, to observe the variation of SWC at the various depths. The footprint of the CRNS for SWC observation in the meadow was about 580 m, and the mean measuring depth was about 31 cm according to the general calculation equations. The reference neutron flux for dry soil (N 0 ) had a mean and coefficient of variation of 8686 and 3%, respectively, and remained substantially invariant throughout the measuring period. The five SWCs from the independent field samples almost passed through the SWC trend of the CRNS, the root mean square error (RMSE) was 0.011 m 3 m À3 for the CRNS and oven-drying method. The time series of SWC measured by the CRNS agreed well with the mean SWC series to a depth of 20 cm measured by the weather station. The trend of SWC measured by the Em-50s generally agreed with the trend of SWC measured by the CRNS, but some values and variations of SWC differed between the Em-50s and CRNS data. Because of the good agreement between the CRNS and independent field samples, we suspect that this disagreement is due to an insufficient representativeness of point observations and the distances of the points from the CRNS. The diurnal variation of hourly SWC from the CRNS was sinusoidal during a dry period, peaking at 11:00 and was minimum at 18:00 (Beijing time), with a range of 1%. Overall, the CRNS measured SWC in the AME with an acceptable accuracy, providing a scientific basis for the promotion and application of the CRNS in high, cold ecosystems.

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“…edu/). Corrections were applied as by Zreda et al (2012). Water vapour corrections were applied with respect to dry air (Bogena et al, 2013).…”

Section: Calibration and Validation Data: Ps Crns And Eddy-covarianmentioning

confidence: 99%

Land surface model performance using cosmic-ray and point-scale soil moisture measurements for calibration

Iwema

Rosolem

Rahman

et al. 2017

Hydrol. Earth Syst. Sci.

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Abstract. At very high resolution scale (i.e. grid cells of 1 km 2 ), land surface model parameters can be calibrated with eddy-covariance flux data and point-scale soil moisture data. However, measurement scales of eddy-covariance and point-scale data differ substantially. In our study, we investigated the impact of reducing the scale mismatch between surface energy flux and soil moisture observations by replacing point-scale soil moisture data with observations derived from Cosmic-Ray Neutron Sensors (CRNSs) made at larger spatial scales. Five soil and evapotranspiration parameters of the Joint UK Land Environment Simulator (JULES) were calibrated against point-scale and Cosmic-Ray Neutron Sensor soil moisture data separately. We calibrated the model for 12 sites in the USA representing a range of climatic, soil, and vegetation conditions. The improvement in latent heat flux estimation for the two calibration solutions was assessed by comparison to eddy-covariance flux data and to JULES simulations with default parameter values. Calibrations against the two soil moisture products alone did show an advantage for the cosmic-ray technique. However, further analyses of two-objective calibrations with soil moisture and latent heat flux showed no substantial differences between both calibration strategies. This was mainly caused by the limited effect of calibrating soil parameters on soil moisture dynamics and surface energy fluxes. Other factors that played a role were limited spatial variability in surface fluxes implied by soil moisture spatio-temporal stability, and data quality issues.

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COSMOS: the COsmic-ray Soil Moisture Observing System

Cited by 486 publications

References 39 publications

Assessment of irrigation physics in a land surface modeling framework using non-traditional and human-practice datasets

Assessment of irrigation physics in a land surface modeling framework using non-traditional and human-practice datasets

Application of cosmic-ray neutron sensing to monitor soil water content in an alpine meadow ecosystem on the northern Tibetan Plateau

Land surface model performance using cosmic-ray and point-scale soil moisture measurements for calibration

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