Three-dimensional Sound Speed Modeling In Seawater Based On Argo Buoy

The purpose of Argo's plan is to quickly obtain real-time ocean observation data in a large area,continuously improve the ocean data and provide data support for ocean research.However,the deployment of Argo buoys is relatively sparse and unevenly distributed in different sea areas.The existing observation data cannot guarantee the needs of actual engineering and research.Therefore,It is great significant to study the sound speed,predict the sound speed profiles,and explore the method of establishing a three-dimensional sound speed field in the ocean.At this stage,it is still in the initial stage to realize the prediction of sound speed profile anywhere.The construction of the "21st Century Maritime Silk Road" is an important measure for China to deepen reform and opening up in the new era.Therefore,Argo buoy data is selected to study the three-dimensional sound speed prediction model in the Arabian Sea.The main research contents and conclusions of the paper are as follows:(1)Summarize the domestic and foreign research status of the sparse representation of sound speed profile and the establishment of three-dimensional sound speed field.Introduce the acquisition method of seawater sound speed profile and the characteristics of deep sea sound speed profile,and analyze the source of sound speed measurement error and the method of error evaluation.(2)Because the length of Argo data obtained in the depth dimension is inconsistent with the sampling points,based on the MATLAB platform,the observation data is interpolated,fitted,and extended to generate standardized data with the same depth and uniform intervals.(3)In this paper,the empirical orthogonal function method and dictionary learning method are used to sparsely represent the sound speed profile of the Arabian Sea.The experimental comparison analysis shows that both methods can better represent the sound speed profile.Compared with the empirical orthogonal function method,the dictionary learning method is possible to accurately represent the sound speed profile with fewer atoms.(4)Based on the above two methods of sparse representation of sound speed profile,combined with spatial inverse distance weighted average method and Kriging space interpolation method,the coefficient parameters of prediction points are obtained,and a three-dimensional sound speed field model is constructed to realize three-dimensional prediction of sound speed profile.In this paper,part of the data in the experimental sea area is selected as the test data.The results show that when the historical sample data around the test SSP is few,the prediction precision is low;when there are enough sample data around the test SSP,it can be better to predict the sound speed profile,the accuracy of sound speed prediction is better than 1m/s.The two methods reduce the complexity of the two models and greatly improve the operating efficiency.