Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1029/2019WR025647
Licence creative commons licence
Title (Primary) Sensing area‐average snow water equivalent with cosmic‐ray neutrons: The influence of fractional snow cover
Author Schattan, P.; Köhli, M.; Schrön, M.; Baroni, G.; Oswald, S.E.
Source Titel Water Resources Research
Year 2019
Department MET
Volume 55
Issue 12
Page From 10796
Page To 10812
Language englisch
Keywords area‐average snow monitoring; cosmic‐ray neutron sensing; neutron simulations; spatial heterogeneity; fractional snow cover
Abstract Cosmic‐ray neutron sensing (CRNS) is a promising non‐invasive technique to estimate snow water equivalent (SWE) over large areas. In contrast to preliminary studies focusing on shallow snow conditions (SWE urn:x-wiley:wrcr:media:wrcr24357:wrcr24357-math-0001130 mm), more recently the method was shown experimentally to be sensitive also to deeper snowpacks providing the basis for its use at mountain experimental sites. However, hysteretic neutron response has been observed for complex snow cover including patchy snow‐free areas. In the present study we aimed to understand and support the experimental findings using a comprehensive neutron modeling approach. Several simulations have been set up in order to disentangle the effect on the signal of different land surface characteristics and to reproduce multiple observations during periods of snow melt and accumulation. To represent the actual land surface heterogeneity and the complex snow cover, the model used data from terrestrial laser scanning. The results show that the model was able to accurately reproduce the CRNS signal and particularly the hysteresis effect during accumulation and melting periods. Moreover, the sensor footprint was found to be anisotropic and affected by the spatial distribution of liquid water and snow as well as by the topography of the nearby mountains. Under fully snow‐covered conditions the CRNS is able to accurately estimate SWE without prior knowledge about snow density profiles or other spatial anomalies. These results provide new insights into the characteristics of the detected neutron signal in complex terrain and support the use of CRNS for long‐term snow monitoring in high elevated mountain environments.
Persistent UFZ Identifier
Schattan, P., Köhli, M., Schrön, M., Baroni, G., Oswald, S.E. (2019):
Sensing area‐average snow water equivalent with cosmic‐ray neutrons: The influence of fractional snow cover
Water Resour. Res. 55 (12), 10796 - 10812 10.1029/2019WR025647