Some relatively mature mesoscale eddy products have been released for scientific purposes in recent decades.However,the metrics used to identify eddies,the tracking methods,and the definition of the physical parameter...Some relatively mature mesoscale eddy products have been released for scientific purposes in recent decades.However,the metrics used to identify eddies,the tracking methods,and the definition of the physical parameters are all different across the different datasets,so intercomparisons and validation of these datasets are badly needed.Here,the authors intercompare the basic features of ocean mesoscale eddies in the Kuroshio extension region from four eddy datasets—namely,Chelton,GEM-M,Faghmous,and Dong.In the case study,eddy numbers and locations as well as the eddy tracks identified by the four datasets are compared for a specific date.The authors find that all the datasets have different eddy numbers,but more than 50%of identified eddies coincide.GEM-M,with the so-called"segmentation"algorithm,can identify considerably more eddies than others,while Chelton identifies fewer eddies due to tracking errors,which also lead to a long lifespan.From the analysis of the probability distribution function of eddy features,GEM-M eddies tend to have a larger amplitude and radius and Chelton tends to have long-life eddies.It is further found that the geographic distributions and temporal variation of normalized eddy features are highly similar among the four datasets—particularly among Chelton,Fahgmous,and Dong.In addition,the mean trajectories of the four datasets are generally overlapped initially,and then spread after 245 days.The findings help toward better understanding the uncertainties of eddy features in the Kuroshio extension region.展开更多
A simplified parameter identification algorithm for the inverse refractive indexes of the mesoscale eddy and the internal wave in the ocean is proposed by researching into the incident field and the scattered field th...A simplified parameter identification algorithm for the inverse refractive indexes of the mesoscale eddy and the internal wave in the ocean is proposed by researching into the incident field and the scattered field that comprise the total field of a wave in the ocean, considering that the total field and the incident field satisfy the Helmholtz equations and the scattered field conforms to the Sommerfield radiation condition. Two examples for the calculation of refractive index and inverse refractive index respectively of the mesoscale eddy and the internal wave demonstrate the applicability of the algorithm.展开更多
基金supported by National Key R&D Program for Developing Basic Sciences[grant number 2018YFA0605703]the Strategic Priority Research Program of the Chinese Academy of Sciences[grant number XDB42010404]the National Natural Science Foundation of China[grant numbers 41976026,41776030,41931183,and 41931182]。
文摘Some relatively mature mesoscale eddy products have been released for scientific purposes in recent decades.However,the metrics used to identify eddies,the tracking methods,and the definition of the physical parameters are all different across the different datasets,so intercomparisons and validation of these datasets are badly needed.Here,the authors intercompare the basic features of ocean mesoscale eddies in the Kuroshio extension region from four eddy datasets—namely,Chelton,GEM-M,Faghmous,and Dong.In the case study,eddy numbers and locations as well as the eddy tracks identified by the four datasets are compared for a specific date.The authors find that all the datasets have different eddy numbers,but more than 50%of identified eddies coincide.GEM-M,with the so-called"segmentation"algorithm,can identify considerably more eddies than others,while Chelton identifies fewer eddies due to tracking errors,which also lead to a long lifespan.From the analysis of the probability distribution function of eddy features,GEM-M eddies tend to have a larger amplitude and radius and Chelton tends to have long-life eddies.It is further found that the geographic distributions and temporal variation of normalized eddy features are highly similar among the four datasets—particularly among Chelton,Fahgmous,and Dong.In addition,the mean trajectories of the four datasets are generally overlapped initially,and then spread after 245 days.The findings help toward better understanding the uncertainties of eddy features in the Kuroshio extension region.
文摘A simplified parameter identification algorithm for the inverse refractive indexes of the mesoscale eddy and the internal wave in the ocean is proposed by researching into the incident field and the scattered field that comprise the total field of a wave in the ocean, considering that the total field and the incident field satisfy the Helmholtz equations and the scattered field conforms to the Sommerfield radiation condition. Two examples for the calculation of refractive index and inverse refractive index respectively of the mesoscale eddy and the internal wave demonstrate the applicability of the algorithm.
