Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Downscaling hydroclimatic changes over the Western U.S. Based on CAM subgrid scheme and WRF regional climate simulations

Journal Article · · International Journal of Climatology
DOI:https://doi.org/10.1002/joc.1928· OSTI ID:1719126

Global and regional climate simulations have been performed to compare two dynamical downscaling methods, a regional climate model (WRF) and a subgrid parameterization, both driven by a global climate model, for simulating orographic effects and projecting the hydrologic impacts of climate change in the western U.S. Two 10-year simulations were completed for the present (1993-2003) and future (2039-2049) with CAM3 applied a subgrid orographic precipitation scheme and with WRF regional climate model at 15 km spatial resolution Increasing spatial resolution has a large impact on snowpack simulation. Both CAM subgrid scheme and the WRF simulation significantly improved the simulation of snowpck associated with orographic effects. The spatial distributions of the precipitation and snowpack are generally consistent between the CAM Subgrid scheme and WRF simulations, as CAM3 provided the large-scale circulation for both simulations. However, rain-shadow and snowpack-shadow effects are only resolved at the explicit grid resolution. Both downscaling procedures preserved the CAM large-scale features, showing an increase in precipitation in southern states in WUS and a significant decrease in the Pacific Northwest. The WRF simulation indicates larger changes of precipitation and snowpack along the coastal mountains than CAM3. As the WRF model explicitly simulates the interactions of regional atmospheric circulation and the underlying topography, changes in the future climate may lead to larger changes in orographic precipitation than that caused by changes in atmospheric moisture and temperature alone. The surface air temperature increase 0.5-2.0 oC over most of areas with maximum warming in Rockies and northern areas of model domain. Snowpack reduces 20-60% with maximum reductions along the Cascades and the Rockies. Runoff changes show a diverse spatial pattern in different seasons driven by the combined impacts from the changes of precipitation, more precipitation in the form of rain rather than in snow, and less snowpack accumulation in warmer winter.

Research Organization:
Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AC05-76RL01830
OSTI ID:
1719126
Report Number(s):
PNWD-SA-8304
Journal Information:
International Journal of Climatology, Journal Name: International Journal of Climatology Journal Issue: 5 Vol. 30
Country of Publication:
United States
Language:
English

References (31)

A Statistical-Topographic Model for Mapping Climatological Precipitation over Mountainous Terrain journal February 1994
Experimental Weekly to Seasonal U.S. Forecasts with the Regional Spectral Model journal December 2004
The Formulation and Atmospheric Simulation of the Community Atmosphere Model Version 3 (CAM3) journal June 2006
Utility of daily vs. monthly large-scale climate data: an intercomparison of two statistical downscaling methods journal January 2008
Physically Based Global Downscaling: Climate Change Projections for a Full Century journal May 2006
The Sensitivity of Precipitation and Snowpack Simulations to Model Resolution via Nesting in Regions of Complex Terrain journal December 2003
A New Vertical Diffusion Package with an Explicit Treatment of Entrainment Processes journal September 2006
Simulation of the Global Hydrological Cycle in the CCSM Community Atmosphere Model Version 3 (CAM3): Mean Features journal June 2006
Does Increasing Horizontal Resolution Produce More Skillful Forecasts? journal March 2002
Gridded North American monthly snow depth and snow water equivalent for GCM evaluation journal March 2003
Explicit Simulation of Cumulus Ensembles with the GATE Phase III Data: Comparison with Observations journal December 1996
The Kain–Fritsch Convective Parameterization: An Update journal January 2004
A subgrid parameterization of orographic precipitation journal January 1995
Mid-Century Ensemble Regional Climate Change Scenarios for the Western United States journal January 2004
Effects of soot-induced snow albedo change on snowpack and hydrological cycle in western United States based on Weather Research and Forecasting chemistry and regional climate simulations journal January 2009
Declining Mountain Snowpack in Western North America* journal January 2005
NCEP–DOE AMIP-II Reanalysis (R-2) journal November 2002
Introduction to special section: Regional Climate Modeling Revisited journal March 1999
Future change of precipitation extremes in Europe: Intercomparison of scenarios from regional climate models journal January 2006
Parameterizing Subgrid Orographic Precipitation and Surface Cover in Climate Models journal December 1998
Review of scenario selection and downscaling methods for the assessment of climate change impacts on hydrology in the United States pacific northwest journal January 2007
The Community Land Model and Its Climate Statistics as a Component of the Community Climate System Model journal June 2006
Downscaling general circulation model output: a review of methods and limitations journal December 1997
Daily precipitation statistics in regional climate models: Evaluation and intercomparison for the European Alps: DAILY PRECIPITATION STATISTICS IN REGIONAL CLIMATE MODELS journal February 2003
Pacific Northwest Climate Sensitivity Simulated by a Regional Climate Model Driven by a GCM. Part II: 2×CO 2 Simulations journal July 1999
Coupling an Advanced Land Surface–Hydrology Model with the Penn State–NCAR MM5 Modeling System. Part I: Model Implementation and Sensitivity journal April 2001
Intercomparison of Global Reanalyses and Regional Simulations of Cold Season Water Budgets in the Western United States journal December 2003
Representation of Clouds and Precipitation Processes in the Community Atmosphere Model Version 3 (CAM3) journal June 2006
Evaluation of the land surface water budget in NCEP/NCAR and NCEP/DOE reanalyses using an off-line hydrologic model journal August 2001
Physically Based Global Downscaling: Regional Evaluation journal February 2006
The thermodynamic influence of subgrid orography in a global climate model journal November 2002

Similar Records

Downscaling hydroclimatic changes over the Western US based on CAM subgrid scheme and WRF regional climate simulations
Journal Article · Wed Dec 31 23:00:00 EST 2008 · International Journal of Climatology · OSTI ID:1564672

Long-Term Regional Climate Simulations Driven by Two Global Reanalyses and a GCM for the Western United States
Conference · Mon Dec 31 23:00:00 EST 2001 · OSTI ID:15002999

Pacific Northwest climate sensitivity simulated by a regional climate model driven by a GCM. Part 2: 2xCO[sub 2] simulations
Journal Article · Thu Jul 01 00:00:00 EDT 1999 · Journal of Climate · OSTI ID:6378819

Related Subjects