This study was supported by the MOCCA project Grant RTI2018-093941-B-C31 funded by MCIN/AEI/ 10.13039/501100011033 and by "ERDF A way of making Europe". It was also supported by grants PGC2018-099285-B-C21 and PGC2018-099285-B-C22 funded by MCIN/AEI/10.13039/501100011033 and by “ERDF A way of making Europe” NextGenerationEU/PRTR. Angel Amores was funded by the Conselleria d’Educació, Universitat i Recerca del Govern Balear through the Direcció General de Política Universitària i Recerca and by the Fondo Social Europeo for the period 2014–2020 (Grant No. PD/011/2019). Daniel Argüeso was funded by Spanish Ministry of Science and Innovation through the EPICC Project (PID2019-105253RJ-I00) and the Beatriz Galindo Programme (BG20/00078)., No

The Tumaco multivariate index (TMI) is a multidecadal monthly index constructed with unique time series of sea surface temperature, surface air temperature and rain measured at Tumaco bay, in the southern Pacific coast of Colombia, and available since 1961. In this work, this index is re-evaluated after the addition of in situ sea level data, and its properties for different standardization periods are compared against oceanic El Niño–Southern Oscillation (ENSO) and other derived indices. In particular, we propose a modified TMI, hereinafter referred as TMI4, whose potential to identify the expected sign and the amount of future variations of rain induced by ENSO events in Colombia is analysed for selected extreme episodes. Results indicate that after the inclusion of sea level data, TMI4 can anticipate the development of El Niño events before the ENSO 3 and some other sea surface temperature-based regional indices, although its predictability depends on the ENSO type (canonical or Modoki). The explanation is that sea level includes new information into TMI4 on the onset of El Niño events. In particular, the signal of intraseasonal sea level anomalies carried by downwelling Kelvin waves is detected at Tumaco tide-gauge. Moreover, the analysis of the differences, both in magnitude and spatial distribution, of rainfall anomalies induced by positive (El Niño) and negative (La Niña) ENSO events characterized by TMI4 are regionally presented. As a result, we find that TMI4 is especially suited for extensive northern and western areas of mainland Colombia. For completeness, in the appendix we briefly introduce the semi-automated implementation of TMI4, including a visual interface, which is currently being tested by personnel within the operational oceanography area at Centro de Investigaciones Oceanográficas e Hidrográficas del Pacífico (Dimar-CCCP).

The spatial distribution, and the monthly and seasonal variability of mesoscale eddy observations derived from the AVISO eddy atlas are assessed in the Caribbean Sea during 1993–2019. The average lifetime for the whole set of eddies is 62 ± 37 days, mean amplitude of 7 ± 4 cm for cyclonic and 7 ± 4 cm for anticyclonic and mean radius of 100 ± 31 km for cyclonic and 108 ± 32 km for anticyclonic. Cyclonic eddies are on average more nonlinear than anticyclonic ones. The spatio-temporal variability in the number of eddy observations is evaluated against the Mean Eddy Kinetic Energy (MEKE) derived from geostrophic currents as well as from seasonal winds. Spatial distribution of eddy observations is correlated with MEKE while the migration of the intertropical convergence zone explains the advection of eddies towards the southern part of the basin.

Mean wave energy flux (hereinafter WEF) is assessed in the Caribbean Sea from a 60-year (1958–2017) wave hindcast. We use a novel approach, based on neural networks, to identify coherent regions of WEF and their association with different climate patterns. This method allows for a better evaluation of the underlying dynamics behind seasonal and inter-annual WEF variability, including the effect induced by the latitudinal migration of the Intertropical Convergence Zone (ITCZ) and the influence of El Niño-Southern Oscillation (ENSO) events. Results show regional differences in WEF variability likely due to both intensification and migration of the ITCZ. WEF exhibits a strong semi-seasonal signal in areas of the continental shelf, with maxima reached in January and June, in agreement with the known sea surface temperature and sea-level pressure variability patterns. At larger scales, WEF shows a significant correlation with the Oceanic Niño Index (ONI, which is the primary index for tracking the ocean part of ENSO climate pattern), depicting positive values in the central and western sides of the basin and negative ones at the eastern side.