A Wet‐Bulb Temperature‐Based Rain‐Snow Partitioning Scheme Improves Snowpack Prediction Over the Drier Western United States
AffiliationUniv Arizona, Hydrol & Atmospher Sci
Univ Arizona, Sch Nat Resources Environm
Univ Arizona, Biosphere 2
Noah-MP land surface model
snow water equivalent
MetadataShow full item record
PublisherAMER GEOPHYSICAL UNION
CitationWang, Y.‐H., Broxton, P., Fang, Y., Behrangi, A., Barlage, M., Zeng, X., & Niu, G.‐Y. (2019). A Wet‐Bulb Temperature‐Based Rain‐Snow Partitioning Scheme Improves Snowpack Prediction Over the Drier Western United States. Geophysical Research Letters, 46, 13,825–13,835. https://doi.org/10.1029/2019GL085722
JournalGEOPHYSICAL RESEARCH LETTERS
RightsCopyright © 2019. American Geophysical Union. All Rights Reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractAccumulation of snowfall during winter and snowmelt in the subsequent spring or earlier summer provides a dominant water source in alpine regions. Most land surface and hydrological models use near-surface air temperature (T-a) thresholds to partition precipitation into snow and rain, underestimating snowfall over drier regions. We developed a snow-rain partitioning scheme using the wet-bulb temperature (T-w), which is closer to the surface temperature of a falling hydrometeor than T-a. T-w becomes more depressed in drier environments as derived from T-w depression equation using T-a and surface air humidity, resulting in a greater fraction of snowfall. We implemented this new T-w scheme in the Noah-MP land surface model and evaluated the model against a high-quality ground-based snow product over the contiguous United States. The results suggest that the new T-w scheme substantially improves the model skill in simulating snow depth and snow water equivalent over most snow-covered grids, especially the higher and drier continental mountain ranges in the Western United States, while it retains the modeling accuracy over the more humid Eastern United States.
Note6 month embargo; published online: 10 December 2019
VersionFinal published version
SponsorsNOAA OARNational Oceanic Atmospheric Admin (NOAA) - USA [NA18OAR4590397]; NASA MAP ProgramNational Aeronautics & Space Administration (NASA) [80NSSC17K0352]; NASA Energy and Water Cycle Study awards [NNH13ZDA001N-NEWS]