Snow process modeling in the North American Land Data Assimilation System (NLDAS): 1. Evaluation of model‐simulated snow cover extent

[1] This study evaluates the cold season process modeling in the North American Land Data Assimilation System (NLDAS) and consists of two parts: (1) assessment of land surface model simulations of snow cover extent and (2) evaluation of snow water equivalent. In this first part, simulations of snow cover extent from the four land surface models (Noah, MOSAIC, Sacramento land surface model (SAC), and variable infiltration capacity land surface model (VIC)) in the NLDAS were compared with observational data from the Interactive Multisensor Snow and Ice Mapping System for a 3 year retrospective period over the conterminous United States. In general, all models simulate reasonably well the regional-scale spatial and seasonal dynamics of snow cover. Systematic biases are seen in the model simulations, with consistent underestimation of snow cover extent by MOSAIC (−19.8% average bias) and Noah (−22.5%), and overestimation by VIC (22.3%), with SAC being essentially unbiased on average. However, the level of bias at the regional scale varies with geographic location and elevation variability. Larger discrepancies are seen over higher elevation regions of the northwest of the United States that may be due, in part, to errors in the meteorological forcings and also at the snow line boundary, where most temporal and spatial variability in snow cover extent is likely to occur. The spread between model simulations is fairly low and generally envelopes the observed data at the mean regional scale, indicating that the models are quite capable of simulating the general behavior of snow processes at these scales. Intermodel differences can be explained to some extent by differences in the model representations of subgrid variability and parameterizations of snow cover extent.

[1]  K. Mitchell,et al.  Assessment of the Land Surface and Boundary Layer Models in Two Operational Versions of the NCEP Eta Model Using FIFE Data , 1997 .

[2]  R. D. Harr,et al.  Some characteristics and consequences of snowmelt during rainfall in western Oregon , 1981 .

[3]  M. Clark,et al.  Characteristics of the western United States snowpack from snowpack telemetry (SNOTEL) data , 1999 .

[4]  Thomas R. Carroll,et al.  Effect of uneven snow cover on airborne snow water equivalent estimates obtained by measuring terrestrial gamma radiation , 1989 .

[5]  C. Daly,et al.  A Statistical-Topographic Model for Mapping Climatological Precipitation over Mountainous Terrain , 1994 .

[6]  N. DiGirolamo,et al.  MODIS snow-cover products , 2002 .

[7]  Jenq-Neng Hwang,et al.  Mapping snow water equivalent by combining a spatially distributed snow hydrology model with passive microwave remote-sensing data , 1999, IEEE Trans. Geosci. Remote. Sens..

[8]  B. Ramsay,et al.  The interactive multisensor snow and ice mapping system , 1998 .

[9]  M. Wigmosta,et al.  A distributed hydrology-vegetation model for complex terrain , 1994 .

[10]  J. D. Tarpley,et al.  Surface radiation budgets in support of the GEWEX Continental‐Scale International Project (GCIP) and the GEWEX Americas Prediction Project (GAPP), including the North American Land Data Assimilation System (NLDAS) project , 2003 .

[11]  W. David Rust,et al.  Understanding Utah winter storms: The Intermountain precipitation experiment , 2002 .

[12]  V. Singh,et al.  Computer Models of Watershed Hydrology , 1995 .

[13]  D. Mocko,et al.  Simulation of high latitude hydrological processes in the Torne-Kalix basin : PILPS phase 2(e) - 2: Comparison of model results with observations , 2003 .

[14]  J. D. Tarpley,et al.  The multi‐institution North American Land Data Assimilation System (NLDAS): Utilizing multiple GCIP products and partners in a continental distributed hydrological modeling system , 2004 .

[15]  Y. Xue,et al.  Modeling of land surface evaporation by four schemes and comparison with FIFE observations , 1996 .

[16]  H. Douville,et al.  A comparison of four snow models using observations from an alpine site , 1999 .

[17]  Lifeng Luo,et al.  Snow process modeling in the north american Land Data Assimilation System (NLDAS): 2. Evaluation of model simulated snow water equivalent : GEWEX Continental-Scale International Project, Part 3 (GCIP3) , 2003 .

[18]  J. R. Stitt,et al.  Improved estimates of the areal extent of snow cover from AVHRR data , 1998 .

[19]  R. Koster,et al.  Simulation of high-latitude hydrological processes in the Torne-Kalix basin: PILPS Phase 2(e) 3: Equivalent model representation and sensitivity experiments , 2003 .

[20]  Ross D. Brown,et al.  Northern Hemisphere Snow Cover Variability and Change, 1915-97. , 2000 .

[21]  Fabio Castelli,et al.  Mutual interaction of soil moisture state and atmospheric processes , 1996 .

[22]  David G. Tarboton,et al.  The Influence of the Spatial Distribution of Snow on Basin-Averaged Snowmelt , 1998 .

[23]  Arun Kumar,et al.  Snow–Albedo Feedback and Seasonal Climate Variability over North America , 2001 .

[24]  J. Namias.  Some Empirical Evidence for the Influence of Snow Cover on Temperature and Precipitation , 1985 .

[25]  D. Entekhabi,et al.  The influence of snow cover on northern hemisphere climate variability , 2001 .

[26]  Diana Verseghy,et al.  Snow Cover and Snow Mass Intercomparisons of General Circulation Models and Remotely Sensed Datasets , 1996 .

[27]  E. Bazile,et al.  SnowMIP - An Intercomparison of Snow Models: First Results , 2002 .

[28]  Lifeng Luo,et al.  Streamflow and water balance intercomparisons of four land surface models in the North American Land Data Assimilation System Project , 2004 .

[29]  Thomas R. Carroll,et al.  Spatial modeling and prediction of snow‐water equivalent using ground‐based, airborne, and satellite snow data , 1999 .

[30]  J. D. Tarpley,et al.  Real‐time and retrospective forcing in the North American Land Data Assimilation System (NLDAS) project , 2003 .

[31]  G. Stenchikov,et al.  Changes of Snow Cover, Temperature, and Radiative Heat Balance over the Northern Hemisphere , 1994 .

[32]  K. Mitchell,et al.  Impact of Atmospheric Surface-layer Parameterizations in the new Land-surface Scheme of the NCEP Mesoscale Eta Model , 1997 .

[33]  D. Lettenmaier,et al.  A simple hydrologically based model of land surface water and energy fluxes for general circulation models , 1994 .

[34]  Eric A. Anderson,et al.  National Weather Service river forecast system: snow accumulation and ablation model , 1973 .

[35]  David A. Robinson,et al.  Evaluation of snow extent and its variability in the Atmospheric Model Intercomparison Project , 1998 .

[36]  Dennis P. Lettenmaier,et al.  Hydrologic effects of frozen soils in the upper Mississippi River basin , 1999 .

[37]  Eric F. Wood,et al.  Modeling ground heat flux in land surface parameterization schemes , 1999 .

[38]  Eric F. Wood,et al.  One-dimensional statistical dynamic representation of subgrid spatial variability of precipitation in the two-layer variable infiltration capacity model , 1996 .

[39]  S. Manabe,et al.  A Model Study of the Short-Term Climatic and Hydrologic Effects of Sudden Snow-Cover Removal , 1983 .

[40]  N. Berg,et al.  Rain-induced outflow from deep snowpacks in the central Sierra Nevada, California , 1991 .

[41]  Thomas R. Karl,et al.  Observed Impact of Snow Cover on the Heat Balance and the Rise of Continental Spring Temperatures , 1994, Science.

[42]  R. Dickinson,et al.  The Representation of Snow in Land Surface Schemes: Results from PILPS 2(d) , 2001 .

[43]  Vijay P. Singh,et al.  The NWS River Forecast System - catchment modeling. , 1995 .

[44]  Günter Blöschl,et al.  Scaling issues in snow hydrology , 1999 .

[45]  K. Mitchell,et al.  A parameterization of snowpack and frozen ground intended for NCEP weather and climate models , 1999 .

[46]  D. Mocko,et al.  Simulation of high-latitude hydrological processes in the Torne-Kalix basin: PILPS phase 2(e) - 1: Experiment description and summary intercomparisons , 2003 .