## 4 Discussion  
In this study, we introduced a wavelet-coherence-based network methodology to examine the modulation of internal tides within a mesoscale anticyclonic eddy. Our glider dataset has a spatiotemporal limitation; its spatial coverage is very limited to the upper surface layer (up to 800 m depth) compared to the full depth of 6000 m, and its temporal span is less than 10 days (225 h). Due to these restrictions, the previous analysis by [PERSON] and [PERSON] [45] required additional datasets, such as ADCP from the research vessel ISABU and satellite-based measurements. However, our new approach has an advantage in obtaining the same results solely from the glider's observations.  
By exploiting a wavelet approach optimized for the time-frequency locality, we found the spatial dependency of modulations of internal tides inside the mesoscale anticyclonic eddy, strongly indicating that the eddy is intensified in the surface layer (less than 400 m) and exhibits a varying strength of interaction depending on the distance from the eddy's center point; as reported in [PERSON] and [PERSON] [45], interactions are more actively occurring in the inner center (within 30 km of the eddy's center point) due to its high relative vorticity.  
The distinct behaviors of SIT and DIT networks within the mesoscale eddy, in terms of network metrics, such as mean degree and mean clustering coefficients, are consistent with observational and numerical facts [7; 45] that the horizontal scale of the eddy is comparable to that of the lowest mode of DIT. This distinction is also confirmed by the total weights of MST and modularity-based structural entropy. Consequently, the interactions between internal tides and mesoscale eddies are scale- and position-dependent in the interior of the  
Figure 14: Temporal evolution of structural entropy for SIT networks and DIT networks. (**A**) Temporal evolutions of structural entropy of SIT and DIT networks for the whole depth, with those of randomized SIT and DIT networks. (**B**) Temporal evolutions of structural entropy of SIT and DIT networks for repsective sub-layer.  
eddy. Since a mesoscale eddy changes the nearby current velocity and density (temperature and salinity) [22], it is important to know the interaction level of internal tides and mesoscale eddies in terms of spatial scale and position. To this end, further empirical studies should be conducted.  
The methodology introduced in this study successfully detected the spatial characteristics of a mesoscale anticyclonic eddy in real oceanic environments through network metrics, employing a spatiotemporally limited dataset such as glider measurements. However, this methodology is too limited and has some challenges in its applicability. Also, we should validate the methodology through various empirical studies for its extensive applicability. In the next study, we will verify the validity by applying this method and its variants to other oscillatory systems.  
Conceptualization, G.L. and J.-J.P.; methodology, G.L.; validation, G.L. and J.-J.P.; formal analysis, G.L. and J.-J.P.; investigation, G.L. and J.-J.P.; data curation, J.-J.P.; writing--original draft preparation, G.L.; writing--review and editing, J.-J.-P.; visualization, G.L. and J.-J.P.; supervision, J.-J.P.; project administration, J.-J.P.; funding acquisition, J.-J.P. All authors have read and agreed to the published version of the manuscript.  
This research was supported by the Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (RS-2020-KS201379, RS-2023-00256005).  
The data presented in this study are available upon request from the corresponding author.  
This study has been conducted using E.U. Copernicus Marine Service Information; [[https://doi.org/10.48670/moi-00145](https://doi.org/10.48670/moi-00145)]([https://doi.org/10.48670/moi-00145](https://doi.org/10.48670/moi-00145)), accessed on 1 December 2023.  
The authors declare no conflicts of interest.