Impact of the ENSO phenomenon on wave variability in the Pacific Ocean for wind sea and swell waves

Using wave data from 1960 to 1990 from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis ERA-40 dataset and the ERA-5 reanalysis dataset (1990-2018), this paper presents a comprehensive study on the spatial and temporal variability of wind sea wave height (Hw), swell wave height (Hsw) and mixed significant wave height (Hs) in the Pacific during the warm (El Nin similar to o) and cold (La Nin similar to a) ENSO phases. The main findings show that During DJF, the Hsw is dominated by strong winds and large waves from extratropical cyclones in the North Pa-cific, especially from 1960 to 1990. However, from 1990-2018 these maximum values extend into the subtropical crest of the Pacific Ocean and the southeast trade winds increase during La Nin similar to a. The annual cycle of Hw, Hsw and Hs for specific points located from the west center toward the east center along the equatorial Pacific for the analyzed decades show a strong transition in the locations of the maximum and minimum values during the year. In this sense, the eastern point is more highly influenced by the swell systems that flow from the northwest and southwest of the southern hemisphere associated with the intensification of winds during the occurrence of La Nin similar to a. It is therefore not possible to determine a single period of maximum and minimum values. During the decades of 1990-2018, the difference in swell wave height during La Nin similar to a compared to El Nin similar to o increased throughout the year compared to 1960-1990. During the 1960-1990 period, the maximum values were detected in JJA for both El Nin similar to o and La Nin similar to a in an area that extends from Peri and ends toward the eastern center of the Colombian Pacific Basin.