Hydroclimate of the Western United States Based on Observations and Regional Climate Simulation of 1981–2000. Part II: Mesoscale ENSO Anomalies

Abstract The hydroclimate of the western United States is influenced by strong interannual variability of atmospheric circulation, much of which is associated with the El Nino–Southern Oscillation (ENSO). Precipitation anomalies during ENSO often show opposite and spatially coherent dry and wet patterns in the Northwest and California or vice versa. The role of orography in establishing mesoscale ENSO anomalies in the western United States is examined based on observed precipitation and temperature data at 1/8° spatial resolution and a regional climate simulation at 40-km spatial resolution. Results show that during El Nino or La Nina winters, strong precipitation anomalies are found in northern California, along the southern California coast, and in the northwest mountains such as the Olympic Mountains, the Cascades, and the northern Rockies. These spatial features, which are strongly affected by topography, are surprisingly well reproduced by the regional climate simulation. A spatial feature investigat...

[1]  D. Cayan,et al.  Local Relationships between United States West Coast Precipitation and Monthly Mean Circulation Parameters , 1984 .

[2]  Chester F. Ropelewski,et al.  North American Precipitation and Temperature Patterns Associated with the El Niño/Southern Oscillation (ENSO) , 1986 .

[3]  Roy W. Koch,et al.  Surface Climate and Streamflow Variability in the Western United States and Their Relationship to Large‐Scale Circulation Indices , 1991 .

[4]  J. M. Landwehr,et al.  Hydro-climatic data network (HCDN); a U.S. Geological Survey streamflow data set for the United States for the study of climate variations, 1874-1988 , 1992 .

[5]  Catherine A. Smith,et al.  Singular value decomposition of wintertime sea surface temperature and 500-mb height anomalies , 1992 .

[6]  Ercan Kahya,et al.  The relationships between U.S. streamflow and La Niña Events , 1994 .

[7]  G. Grell,et al.  A description of the fifth-generation Penn State/NCAR Mesoscale Model (MM5) , 1994 .

[8]  R. E. Livezey,et al.  SST-Forced Seasonal Simulation and Prediction Skill for Versions of the NCEP/MRF Model , 1996 .

[9]  Daniel R. Cayan,et al.  Interannual Climate Variability and Snowpack in the Western United States , 1996 .

[10]  Ming Ji,et al.  Assessing a GCM's Suitability for Making Seasonal Predictions , 1996 .

[11]  James W. Hurrell,et al.  Elevation Dependency of the Surface Climate Change Signal: A Model Study , 1997 .

[12]  The Variability of Wintertime Precipitation in the Region of California , 1997 .

[13]  M. Hoerling,et al.  Annual Cycle of Pacific-North American Seasonal Predictability Associated with Different Phases of ENSO , 1998 .

[14]  Michael D. Dettinger,et al.  North–South Precipitation Patterns in Western North America on Interannual-to-Decadal Timescales , 1998 .

[15]  S. Ghan,et al.  Parameterizing Subgrid Orographic Precipitation and Surface Cover in Climate Models , 1998 .

[16]  A. Gershunov.  ENSO Influence on Intraseasonal Extreme Rainfall and Temperature Frequencies in the Contiguous United States: Implications for Long-Range Predictability , 1998 .

[17]  Arun Kumar,et al.  Simulations of the ENSO Hydroclimate Signals in the Pacific Northwest Columbia River Basin , 1999 .

[18]  D. Cayan,et al.  Precipitation structure in the Sierra Nevada of California during winter , 1999 .

[19]  Daniel R. Cayan,et al.  ENSO and Hydrologic Extremes in the Western United States , 1999 .

[20]  S. Ghan,et al.  Pacific Northwest Climate Sensitivity Simulated by a Regional Climate Model Driven by a GCM. Part I: Control Simulations , 1999 .

[21]  Tim N. Palmer,et al.  Dynamical Seasonal Prediction , 2000 .

[22]  John D. Farrara,et al.  A Seasonal Precipitation and Stream Flow Hindcast and Prediction Study in the Western United States during the 1997/98 Winter Season Using a Dynamic Downscaling System , 2000 .

[23]  T. Barnett,et al.  Predicting and Downscaling ENSO Impacts on Intraseasonal Precipitation Statistics in California: The 1997/98 Event , 2000 .

[24]  J. Shukla,et al.  Seasonal Prediction over North America with a Regional Model Nested in a Global Model , 2000 .

[25]  D. Lettenmaier,et al.  Evaluation of the land surface water budget in NCEP/NCAR and NCEP/DOE reanalyses using an off‐line hydrologic model , 2001 .

[26]  J. Roads,et al.  ECPC's Weekly to Seasonal Global Forecasts , 2001 .

[27]  Y. Qian,et al.  Hydroclimate of the Western United States Based on Observations and Regional Climate Simulation of 1981–2000. Part I: Seasonal Statistics , 2003 .