Code and data for "A Cautionary Tale of Selective Modulation by Tracer Advection Schemes in the Southern Ocean"

We quantify how two distinct tracer advection schemes, TSPAS and PRM, selectively modulate the temporal variability of mesoscale surface geostrophic kinetic energy (SGKE) using an eddy-rich (0.1°) global ocean model. Based on represented spatial patterns of SGKE, we identify 100 high-energy and 100 low-energy subregions (3°×3°), compute area-averaged SGKE time series, and apply CEEMDAN and HHT spectral analysis to reveal scheme-dependent frequency signatures. Then we develop a model-consistent diagnostic framework to decompose SGKE into its barotropic, baroclinic, and coupling components. Applying Principal Component Analysis (PCA) to these components in high-energy subregions, we extract the dominant modes governing mesoscale SGKE variability and quantify their contributions to the SGKE anomaly, thereby elucidating the physical pathways of selective modulation by the tracer advection schemes. Code and data are provided to reproduce the decomposition, subregion selection, spectral analysis, PCA, and all figures.