The Response Of Principal Oscillation Pattern Of Wind Stress To Ocean And Its Diagnostic Analysis And Numerical Simulation

Based on the monthly analysis data of wind stress, which provided by FSU, typical wind stress patterns associated with the El Nino/La Nina are determined with the techniques of POP (Principal Oscillation Pattern) analysis. The results show that the oscillations of zonal wind stress have 35 47 57 months, the oscillations of meridional wind stress have 28 38 months. The correlations between wind stress anomaly over the Tropical Pacific and SSTA using SVD analysis shows that the wind stress patterns are corresponding to ENSO eigenmode. It is suggestive that the explanation, simulation and prediction of El Nino/La Nina evolution in space-time should not be based on a single eigenmode but on their interaction, with emphasis on the fact that superimposition and phase locking are important factors of the event cycle. The authors also indicate that the local oscillation is worthy of consideration too. Numerical studies suggest that long scale and slow-changed oscillations in the zonal wind stress rebuild by POP analysis make the intention of El Nino/La Nina events deeply. It also enlarges their range. But, positive and negative anomaly center is toward west than actual conditions. Other subordinate components such as high-frequency oscillation in the actual wind stress data weaken the intention of El Nino/La Nina events. Long scale oscillations in the meridional wind stress rebuild by POP analysis make the intention of El Nino/La Nina events deeply too. However, the change is slender and the range is adjacent with true position. We also draw a conclusion that the zonal wind stress is more important than the meridional wind stress in creating El Nino/La Nina evolution.