## 2 Study Area and Data Processing
### Data and Processing
Only profiles with quality markers of 'good' or 'probably good' are retained, and additional data screening following [PERSON] et al. [15] is applied to these profiles with rules listed in Table 1.  
Then, based on the altimetry-based eddy identification products, the corresponding Argo profile must be mapped. The decision criterion is whether the position of the profiles \begin{table}
\begin{tabular}{c c} \hline \hline
**Items** & **Condition** \\ \hline Minimum observed depth & \textless{}10 m \\ Maximum observed depth & \textgreater{}1000 m \\ Number of valid points & \textgreater{}40 \\ Depth interval between 0\textasci{}100 m & \(\leq\) 25 m \\ Depth interval between 100\textasci{}300 m & \(\leq\)50 m \\ Depth interval between 300\textasci{}500 m & \(\leq\)75 m \\ Depth interval between 300\textasci{}1000 m & \(\leq\)100 m \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Additional data screening rules for Argo profiles. Figure 2: Argo array statistics in the study area on 14 November 2022 (source from [[https://argo.ucsd.edu](https://argo.ucsd.edu)]([https://argo.ucsd.edu](https://argo.ucsd.edu)), accessed on 14 November 2022). lies within the effective boundaries of the simultaneously identified eddies. The process is illustrated in Figure 3. It can be seen that the profiles are extracted in time and space over both the matching Argo data and the mesoscale eddies. The profile data is then vertically interpolated at 5 m intervals using cubic spline function to ensure a smooth and accurate representation of the data. Furthermore, the temperature anomalies of Argo profiles in eddies are obtained by subtracting the climatological profiles from the Argo temperature measurements. The World Ocean Atlas 2018 (WOA18) [32] is a set of objectively analysed climatological fields of in situ temperature, salinity, dissolved oxygen, and nutrients at standard depths for annual, seasonal, and monthly compositing periods for the World Ocean with 102 depth levels from the surface to 5500 m. The 2018 release updates previous versions of the World Ocean Atlas to include approximately 3 million new oceanographic casts added to the World Ocean Database (WOD) since the previous release, as well as renewed and updated quality control. For research purposes, the monthly statistical mean temperature on the \(1/4^{\circ}\) grid for the decadal periods 2005-2017 is used in this study. The corresponding data are available at [[https://www.ncei.noaa.gov/access/world-ocean-atlas-2018/](https://www.ncei.noaa.gov/access/world-ocean-atlas-2018/)]([https://www.ncei.noaa.gov/access/world-ocean-atlas-2018/](https://www.ncei.noaa.gov/access/world-ocean-atlas-2018/)), accessed on 24 February 2024. Similarly, the monthly climate fields from WOA18 corresponding to the position and month of each Argo profiling float are also interpolated using cubic spline function to have 199 depth levels with 5 m depth steps between 10 and 1000 m. Vertical interpolation was used to simplify the model regression method so that all data had the same vertical axis and to avoid occasional gaps. To make best use of the data, and to avoid interference from surface environmental factors, the shallowest depth level was chosen to be 10 m. Four Argo temperature profiles, falling within the CEs and AEs on a single day, are randomly selected and presented in Figure 4a. These profiles exhibit varying near-sea surface temperatures, with minor temperature fluctuations in the mixed layer and decreasing temperatures following different gradients with increasing depth. Furthermore, the climatic temperature profiles corresponding to the same locations and months of these Argo profiles are shown in Figure 4b. The profiles are smoother than those shown in Figure 4a, and once more, different characteristics can be observed. To demonstrate the temperature anomalies induced by mesoscale eddies, it is necessary to perform a comparison operation of the two. Figure 3: Mapping process of Argo profiles and mesoscale eddy dataset.