Method research about extraction of internal tide using altimeter data
Author(s): WANG Bin, Z HANG Xiaoshuang, LYU Xianqing, LIU Ning
Pages: 266-272
Year: 2015 Issue: 3
Journal: Journal of PLA University of Science and Technology(Natural Science Edition)
Keyword: altimetry data; internal tide; extraction method;
Abstract: 10-year ocean topography experiment(TOPEX/Poseidon)(T/P)along-track altimetry was used to conduct a method research on the extraction of internal tide.Firstly,the harmonic analysis result about altimeter data was compared with historieal data to check whether the harmonic analysis method used in this paper is reliable.Then the method of polynomial fitting was used to extract the M2 internal tide sea surface signals.In this procedure,two strategies were used to fit the along-track harmonic constants:one to fit the values A (amplitude)and G (phase-lag)separately,and the other to fit the values AcosG and AsinG separately.The comparison of the results obtained from these two different strategies shows that the latter is better than the former,because it can better separate the barotropic and baroclinic compo-nents.With the latter strategy the comparison among the results of 3 ~15th order polynomial fitting was given.The results show that the 1 1th order polynomial fitting is the best,which can completely separate the barotropic and baroclinic components.
Pages: 266-272
Year: 2015 Issue: 3
Journal: Journal of PLA University of Science and Technology(Natural Science Edition)
Keyword: altimetry data; internal tide; extraction method;
Abstract: 10-year ocean topography experiment(TOPEX/Poseidon)(T/P)along-track altimetry was used to conduct a method research on the extraction of internal tide.Firstly,the harmonic analysis result about altimeter data was compared with historieal data to check whether the harmonic analysis method used in this paper is reliable.Then the method of polynomial fitting was used to extract the M2 internal tide sea surface signals.In this procedure,two strategies were used to fit the along-track harmonic constants:one to fit the values A (amplitude)and G (phase-lag)separately,and the other to fit the values AcosG and AsinG separately.The comparison of the results obtained from these two different strategies shows that the latter is better than the former,because it can better separate the barotropic and baroclinic compo-nents.With the latter strategy the comparison among the results of 3 ~15th order polynomial fitting was given.The results show that the 1 1th order polynomial fitting is the best,which can completely separate the barotropic and baroclinic components.
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