Search

Mainly driven by wind stress, the upper ocean dynamic processes in the North Pacific Ocean serve as important pathways for mass and energy exchanges of the global ocean and thus play an essential role in modulating the global climate. In this study, eight commonly used surface wind datasets are compared on mean state, seasonal and interannual time scales over the North Pacific Ocean. The dataset-derived wind stress, wind stress curl, and Sverdrup stream function and their effects on the current structure, which are illustrated by a set of 1.5-layer linear reduced gravity ocean model experiments, are thoroughly compared. The results show that for each time scale, the spreads among the tested products for the wind stress curl, Sverdrup stream function, thermocline displacement, and North Equatorial Current (NEC)/North Equatorial Countercurrent (NECC) transport are relatively large, caused by the small spread among the tested products for zonal/meridional wind stress occurring in the open ocean/nearshore water. MERRA2 and NCEP/DOE are the dominant contributors to the spread in the zonal and meridional wind stress and thus in the other variables, respectively, indicating that they could force a more fluctuating current field. On the interannual scale, the simulated latitudinal positions of the NEC/NECC are sensitive to the choice of wind forcing. NCEP/NCAR and ASCAT deviate most from the ensemble mean. Generally, ERA5 shows the most resemblance with the ensemble mean over the tested products. [ABSTRACT FROM AUTHOR]

The wind stresses and their derived wind stress curls, and Sverdrup stream functions over the South China Sea (SCS) in typical winter and summer months from nine datasets are compared. The datasets include CCMP, CERSAT, ASCAT, QSCAT, NCEP, QSCAT-NCEP, HR, ERA-40, and ERA-Interim. Results show that the overall patterns of the wind stresses, wind stress curls, and Sverdrup stream functions from different datasets are similar. However, their magnitudes are remarkably different. Among them, ERA-40 is the smallest while HR is the largest. The former is about 40 % smaller than the mean value, while the latter is about 50 % greater than the mean value. The spatial resolution is important for the presentation of the wind stress features in the SCS. It can be expected that the same numerical ocean model driven by different wind stress would yield remarkably different results. [ABSTRACT FROM AUTHOR]