Table 1.
Summary of numerical models’ horizontal resolution. Note that EC-Earth3P-LR’s original model identification name is EC-Earth3P; here we label it as EC-Earth3P-LR for consistency with the other models. In the nomenclature, LR stands for Low Resolution, HR stands for High Resolution, VHR stands for Very High Resolution, XR stands for eXtra Resolution. Ih Had-GEM3-GC31 models, L, M and H stand respectively for Low, medium and High.
Fig 1.
SST-THF covariances for lag = -1, 0, 1 (upper, mid, and bottom rows, respectively) in observations (J_OFURO3 and OAFLUX), and model simulations at (top panel) low and (bottom panel) high resolution.
Positive lag means SST leads over THF.
Fig 2.
SST tendency - THF covariances for lag = -1, 0, 1 (rows).
Positive lag means SST leading over THF in observations and model simulations. Low horizontal resolution (top panel) and high horizontal resolution (bottom panel) results.
Fig 3.
Correlation plots for 2° boxes (5° for HadGEM3-GC31-LL) centered at 15.0°E, 41.5°S (yellow squares in panel (f)).
Blue lines represent SST-THF correlation, red lines represent SST tendency-THF correlation. Thicker solid lines are for observation (J-OFURO3), and thinner solid lines for high horizontal resolution configurations while thinner dashed lines are used for low horizontal resolution configurations. For simplicity of the figure, we only present observations from J-OFURO3 for comparison. In panel F, two boxes are shown to include the wider area used to sample HadGEM3-GC31-LL model.
Fig 4.
As in Fig 3, but for an open-ocean region centered at 16°W, 20°S (red squares in panel F).
Fig 5.
Symmetry index (SI) for the correlations shown in Fig 3.
The SI is computed from the lagged SST–THF and SST tendency–THF correlations to quantify the symmetry of the curves around zero lag. Models such as EC-Earth3P and HadGEM3-GC31-LL display strongly anti-symmetric behavior; thus, their SI values fall outside the expected range (above 1) and are not shown. For HadGEM3-GC31, the mid-resolution configuration is labeled as HM. (O refers to the horizontal resolution of the ocean component, and A to that of the atmosphere.).
Fig 6.
SST-THF correlation plots for different lags and filtering scales.
Low-resolution observational data in the left panels and high-resolution data in the right panels. The region selected is 15°E 41.5°S. Both J_OFURO and OAFLUX are included as well (top panel).
Fig 7.
SST tendency-THF correlation plots for different lags and filtering scales.
Low-resolution observational data in the left panels and high-resolution data in the right panels. The region selected is 15°E 41.5°S. Both J_OFURO and OAFLUX are included as well (top panel).
Fig 8.
Transition scale for numerical models and observations.
Ec-Earth3P-LR and HadGEM3-GC31-LL are missing since they do not show a regime transition. The region selected is 15°E 41°S. (O represents ocean model resolution, and A represents Atmospheric model resolution).