850-hPa
; Atmospheric model intercomparison projects
; Geopotential height
; Inner domain
; Lateral boundary
; Meridional winds
; Mesoscale model
; Model errors
; Model evaluation
; North American
; Reanalysis
; Regional climate modeling
; Regional model
; Spatial variability
; Two-way nesting
; Weather research and forecasting models
; WRF Model
; Zonal wind
; Computer simulation
; Weather forecasting
; Climate models
; climate modeling
; error correction
; mesoscale meteorology
; numerical model
; regional climate
; weather forecasting
; United States
英文摘要:
This study evaluates interior nudging techniques using the Weather Research and Forecasting (WRF) model for regional climate modeling over the conterminous United States (CONUS) using a two-way nested configuration. NCEP-Department of Energy Atmospheric Model Intercomparison Project (AMIP-II) Reanalysis (R-2) data are downscaled to 36 km × 36 km by nudging only at the lateral boundaries, using gridpoint (i.e., analysis) nudging and using spectral nudging. Seven annual simulations are conducted and evaluated for 1988 by comparing 2-m temperature, precipitation, 500-hPa geopotential height, and 850-hPa meridional wind to the 32-km North American Regional Reanalysis (NARR). Using interior nudging reduces the mean biases for those fields throughout the CONUS compared to the simulation without interior nudging. The predictions of 2-m temperature and fields aloft behave similarly when either analysis or spectral nudging is used. For precipitation, however, analysis nudging generates monthly precipitation totals, and intensity and frequency of precipitation that are closer to observed fields than spectral nudging. The spectrum of 250-hPa zonal winds simulated by the WRF model is also compared to that of the R-2 and NARR. The spatial variability in theWRFmodel is reduced by using either form of interior nudging, and analysis nudging suppresses that variability more strongly than spectral nudging. Reducing the nudging strengths on the inner domain increases the variability but generates larger biases. The results support the use of interior nudging on both domains of a two-way nest to reduce error when the inner nest is not otherwise dominated by the lateral boundary forcing. Nevertheless, additional research is required to optimize the balance between accuracy and variability in choosing a nudging strategy.
Atmospheric Modeling and Analysis Division, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
Recommended Citation:
Bowden J.H.,Otte T.L.,Nolte C.G.,et al. Examining interior grid nudging techniques using two-way nesting in the WRF model for regional climate modeling[J]. Journal of Climate,2012-01-01,25(8)