The Effect Of Wave Transpot On Upper Ocean Temperature

Ocean waves are not only the typically process of small-scale movements, but also is the important movement in the air-sea interface. Due to the continuity of waves, it would have an incredible impact on the upper oceans. Wave process includes wave-current interaction, wave breaking, nearshore wave reflection and diffraction, wave-induced water transport and the wave mixing and so on. This paper studies the relationship between the wave-induced water transport and the sea surface temperature anomalies in eastern equatorial Pacific and the effect of wave transport flux residual on the upper ocean. Data analysis and numerical experiments are used as the research methods, and using a variety of statistical methods, including EOF decomposition, band-pass filtering, correlation analysis, error analysis, Fourier transform and so on.The mean wave direction in south and north Westerlies regions is the west, and it is the east in tropical. The east coast of the South Pacific which keeping the southwest northeast wave direction throughout the year is mainly dominated swell. The direction of wave-induced Stokes transport is the same to mean wave direction. The E-W components of Stokes transport volume are mainly band-like distributed with the maximum in the south Westerlies which the peak value is at the southern Indian Ocean. They are relatively weaker in Tropical. The directions of S-N components are the south, which transport to the equator in the southern hemisphere with an obvious east intensification in the eastern boundary, and transport from the equator in the Northern Hemisphere. The magnitude of Stokes and Ekman transport volume can be compared. They are much closer in the north and south Westerlies, but Stokes transport is mainly the E-W transport, and the Ekman transport is much larger in the S-N components with the maximum in tropic which the mainly directions are from the equator to north or south. For the eastern equatorial Pacific that we are more concerned about, the contribution of Stokes transport is more than Ekman transport because that the waves maintain positive transport to the equator throughout the year. There are two main paths through which wave-induced transport influence the SST anomaly in the eastern equatorial Pacific that are the W-E components along the equator and the S-N components along the east coast of the ocean. The spatial and temporal characteristics of Stokes transport and the primary period in Tropical Pacific and Southern Ocean were analyzed by the empirical orthogonal decomposition method. The analysis shows that Stokes transport anomaly in these two regions has the same characteristics of the eastward transmission, and the main periods are 5.2, 3.7,2.45 year, respectively, which are the same to SST anomalies oscillation cycle in the eastern equatorial Pacific. It is indicates that the Stokes transport in these two regions has a close relationship with the SST anomaly in the eastern equatorial Pacific.The eastern equatorial Pacific SST anomaly is represented by the Nino3 index. When the SST anomaly is greater than 0.5℃ and lasted six months or more, it is defined as a warm event. When the SST anomaly is less than -0.5℃ and lasted six months or more, it is defined as a cold event. In a warm event, the directions of Stokes transport are west along the equator in all spring and summer types. That is to say, Stokes transport continuous transfers the warm water from west to east before the warm event outbreaks. But, they are different in the east coast of the ocean that Stokes transport contributes warm water (negative anomaly) during the spring type and contributes cold water (positive anomaly) during the summer type. In a cold event, the Stokes transport is predominantly east anomaly along the equator, which the warm water transported to the east is less than normal. In contrast, the Stokes transport is predominantly south anomaly in the east coast of the ocean, in which the cold water transported to the north is significant greater than normal. Two pathways of Stokes transport prepare conditions for the outbreak of the cold event. For the NON type, the Stokes transport is west anomaly remained from the warm event along the equator, but there is no obvious transport characteristics. In contrast, the Stokes transport is predominantly north anomaly in the east coast of the ocean, in which the cold water transported to the north is significant less than normal, which would inhibit the outbreak of the cold events to some extent. Stokes heat transport is calculated, that further illustrates the contribution of large-scale wave-induced transport to the change of SST anomalies in the eastern equatorial Pacific. Correlation analysis between Stokes transport and Nino3 index shows that the correlation coefficient is largest when SST anomalies lag Stokes transport six months along the equator and 15-20 months in east coast of the ocean. As an important part of the Water Transport, the effect of Stokes transport on the SST anomalies in the equatorial eastern Pacific should not be ignored.Waves transport flux residual is one of the important physical mechanisms for the upper ocean. It is showed that KPP parameterization schemes which hadn’t included wave process underestimated vertical diffusion coefficient and the wave process by analyzing the boundary layer depth. The effects of wave transport flux residual (Bsmt) on the upper ocean is studied through carrying out the control run(CR) and a series of sensitive runs(SR) with ROMS model. In this study, the important role of Bsmt is revealed by comparing the ocean temperature, statistical analysis of errors and evaluating the mixed layer depth. It is shown that the overestimated SST is improved effectively when the Bsmt is incorporated to the vertical mixing scheme. As can be seen from the vertical structure of temperature 28℃ isotherm changes from 20m in CR to 35m in SR3, which is more close to the observation. The numerical results of the ocean temperature show improvement in summer and in tropical zones in winter, especially in the strong current regions in summer. The temperature correlation coefficient between SR and SODA data was increased from 0.9013 to 0.9162 in February and was increased from 0.8881 to 0.8881 in August.The simulation results have a close relationship with undetermined coefficient of Bsmt, sensitivity studies shows that a coefficient about 0.1 is reasonable value in the model.