Research On Distributions And Variations Of Sea Wave And Wave Energy In South China Sea During Recent20Years

Variety of wave fields in South China Sea (SCS) has become the focus of oceanresearch among many scholars. In recent decades, the ocean disasters occurred in SCSare increasing,and also become the key factor in restricting the economicdevelopment of SCS.Researching the wave fields of SCS has be of vital importancefor maritime shipping、maritime military and energy development and utilization.This paper utilizing high-precision Reanalysis wind field structured by mesoscaleatmospheric model WRF (Weather Research and forecast) numerical pattern fromJanuary1986to December2005,adopts the internationally advanced third-generationwave model SWAN40.85(Simulating Waves Nearshore) to simulate wave field inSCS for long time series。The paper analyzes the changes in the wave field in SCS，including seasonal changes and interannual variability of the significant wave height(Hs)、the extreme value of return period and seasonal changes and interannualvariability of wave energy.Due to the influence of the winter monsoon,the significant wave height reachesthe maximum in winter and reaches the minimum in spring,with a distribution ofnortheast-southwest;from the distribution of the averaged Hs, the maximumlocated in the middle of the SCS,and the distribution is consistent with the seasonalones; meanwhile,the paper makes a comparison between the observation data and thesimulation ones,showing that there is a good consistence between the simulatedresults and the observations.This paper selects P-Ⅲ distribution curve to estimate the return period ofextreme value of Hs and averaged period,and the results indicate that the P-Ⅲdistribution curve has a good ability to make the Hs and mean period fitting.Researching the extreme value of the return period is very important forsea voyage、harbor construction and fishing.Wave energy resources are abundant in SCS,making it an advantagein building wave energy power stations in SCS.Through the analysis of theSouth China Sea wave energy,it is indicated that the wave energy is much largerthan the conventional estimate.The maximum value of the energy flux density isin winter,with a relatively high stability;what’s more,through calculating thefrequency of the energy flux density level,it is showed that,frequency of energyflux density greater than6kW/m reaches more than80%in SCS,and thedistribution of high frequency band presents northeast-southwest.,consisting withthe distribution of the wave energy’s high value area.South China Sea is a typhoon-prone area,so researching the wave field changesof the typhoon process is quite necessary.In this paper,we select typhoon“HAGUPIT” numbered0814as an example. Comparing the results with theobservations,we have a conclusion that the two has a good consistence with each other.At the same time, the change of the entire wave field represents the process oftyphoon.In this paper,we use SWAN to simulate the wave field in SCS. By comparing thesimulated results with Satellite altimeter data and observations, it is clear that theeffect of the simulation is robust, which means that SWAN can simulate wave fieldwell in SCS.