Evaluation of Wind and Wave Simulations using Different Global Reanalyses

Abstract

Sea surface wind plays an important role in oceanic phenomena and coastal environment. There are many sources of meteorological data available, both global and regional, and they differ not only in spatial and temporal resolution, but also in the number of observations included in the reanalysis and in the method of data assimilation used. The performance of the weather research and forecasting (WRF) model and its variational data assimilation system (WRFDA) with two global reanalyses (ERA-Interim and NCEP FNL) used as initial and lateral boundary conditions has been assessed during the period from January to December of 2014. Both WRF model simulations using the ERA-interim and the NCEP FNL are in good agreement with observations, with correlation coefficients for 10-m wind speed ranging from 0.81 to 0.88 and from 0.77 to 0.88, respectively. Both the ERA-Interim and the NCEP FNL are good choices for the model's initial and lateral boundary conditions, while the ERA-Interim simulation showed better results for surface pressure, wind direction and speed. As a result, the ERA-Interim simulation shows better results for the significant wave height and mean wave period. The results of this study should provide some guidance for the improvement and development of WRF simulation, skill assessment of numerical weather prediction systems, and guidance for further research. Furthermore, the reanalyses can be useful for offshore and coastal researchers in estimating extreme sea states and designing specific offshore and coastal structures.