Biological and Environmental Research - Earth and Environmental System Sciences
Earth and Environmental System Modeling

Evaluation of Snow Water Equivalent in NARCCAP Simulations, Including Measures of Observational Uncertainty

TitleEvaluation of Snow Water Equivalent in NARCCAP Simulations, Including Measures of Observational Uncertainty
Publication TypeJournal Article
Year of Publication2017
JournalJournal of Hydrometeorology
Volume18
Number9
Pages2425-2452
Abstract / Summary

This study evaluates snow water equivalent (SWE) over North America in the reanalysis-driven NARCCAP regional climate model (RCM) experiments. Examination of SWE in these runs allows for the identification of bias due to RCM configuration, separate from inherited GCM bias. SWE from the models is compared to SWE from a new ensemble observational product to evaluate the RCMs’ ability to capture the magnitude, spatial distribution, duration, and timing of the snow season. This new dataset includes data from 14 different sources in five different types. Consideration of the associated uncertainty in observed SWE strongly influences the appearance of bias in RCM-generated SWE. Of the six NARCCAP RCMs, the version of MM5 run by Iowa State University (MM5I) is found to best represent SWE despite its use of the Noah land surface model. CRCM overestimates SWE because of cold temperature biases and surface temperature parameterization options, while RegCM3 (RCM3) does so because of excessive precipitation. HadRM3 (HRM3) underestimates SWE because of warm temperature biases, while in the version of WRF using the Grell scheme (WRFG) and ECPC-RSM (ECP2), the misrepresentation of snow in the Noah land surface model plays the dominant role in SWE bias, particularly in ECP2 where sublimation is too high.

URLhttp://dx.doi.org/10.1175/jhm-d-16-0264.1
DOI10.1175/jhm-d-16-0264.1
Journal: Journal of Hydrometeorology
Year of Publication: 2017
Volume: 18
Number: 9
Pages: 2425-2452
Publication Date: 09/2017

This study evaluates snow water equivalent (SWE) over North America in the reanalysis-driven NARCCAP regional climate model (RCM) experiments. Examination of SWE in these runs allows for the identification of bias due to RCM configuration, separate from inherited GCM bias. SWE from the models is compared to SWE from a new ensemble observational product to evaluate the RCMs’ ability to capture the magnitude, spatial distribution, duration, and timing of the snow season. This new dataset includes data from 14 different sources in five different types. Consideration of the associated uncertainty in observed SWE strongly influences the appearance of bias in RCM-generated SWE. Of the six NARCCAP RCMs, the version of MM5 run by Iowa State University (MM5I) is found to best represent SWE despite its use of the Noah land surface model. CRCM overestimates SWE because of cold temperature biases and surface temperature parameterization options, while RegCM3 (RCM3) does so because of excessive precipitation. HadRM3 (HRM3) underestimates SWE because of warm temperature biases, while in the version of WRF using the Grell scheme (WRFG) and ECPC-RSM (ECP2), the misrepresentation of snow in the Noah land surface model plays the dominant role in SWE bias, particularly in ECP2 where sublimation is too high.

DOI: 10.1175/jhm-d-16-0264.1
Citation:
McCrary, R, S McGinnis, and L Mearns.  2017.  "Evaluation of Snow Water Equivalent in NARCCAP Simulations, Including Measures of Observational Uncertainty."  Journal of Hydrometeorology 18(9): 2425-2452.  https://doi.org/10.1175/jhm-d-16-0264.1.