Comparison of Analysis and Spectral Nudging Techniques for Dynamical Downscaling with the WRF Model over China

Figure 8

The model biases of monthly mean geopotential height (shading in units of meter) and horizontal winds (vector in units of 5 m/s with NN, but 2 m/s with AN and SN) at 500 hPa ((a)–(c)) and monthly mean water vapor mixing ratio (shading in units of q/kg) and horizontal winds at 700 hPa ((d)–(f)) in June, 2011. Respectively, (a) and (d) are the biases simulated with the no nudging experiment (NN), (b) and (e) are the biases simulated with the analysis nudging experiment (AN), and (c) and (f) are the biases simulated with the spectral nudging experiment (SN). All the biases are defined by the departure of WRF simulations from ERA-IN. Gray zones are the missing value masked by the topography.

(a) NN-ERA

(b) AN-ERA

(c) SN-ERA

(d) NN-ERA

(e) AN-ERA

(f) SN-ERA