Surface marine wind from the NCEP/NCAR and NCEP/DOE-II reanalyses

The NCEP-NCAR Reanalysis (Kalnay et al. 1996, Kistler et al. 2001, hereafter R1) is available from 1948 to present, the newer NCEP-DOE Reanalysis II (hereafter R2) is available from 1979 to present. The R2 provided upgrades to the forecast model (Kanamitsu et al., 2002). The implementation of the Hong-Pan planetary boundary layer non-local vertical diffusion scheme (Hong and Pang, 1996), a smoothed orography and different convective parameterizations may cause changes in the wind speed relative to R1. Both reanalyses are intercompared concerning the forecast wind speed at 10 m height. Main focus of the comparison is the eastern North Atlantic and the North Sea. The results show a strong systematic bias between the forecast 10 m wind speed of both reanalyses (see Figure 1). Comparison with marine in situ observations and QuikSCAT wind speed retrievals indicate that R1 10 m forecasts are closer to reality. Figure 1: Bias between the 10 m forecast wind speed of R2 and R1 in 1998. Literature: Hong, S.-Y. and Pang, H.-L. (1996). Nonlocal boundary layer vertical diffusion in a medium-range forecast model. Mon. Wea. Rev., 124:2322–2339. Kalnay et al. (1996). The NCEP/NCAR 40-year Reanalysis Project. Bull. Amer. Meteorol. Soc., (77):437–471. Kanamitsu et al. (2002). NCEP-DOE AMIP-II Reanalysis (R-2). Bulletin Am. Meteorol. Soc., 83(11):1631–1643. Kistler et al. (2001). The NCEP-NCAR 50-year reanalysis: