What happens to the ocean surface gravity waves when ENSO and MJO phases combine during the extended boreal winter?

• Published in: Climate dynamics Vol. 54; no. 3-4; pp. 1407 - 1424
• Main Authors: Godoi, Victor A., de Andrade, Felipe M., Durrant, Tom H., Torres Júnior, Audalio R.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2020; Springer; Springer Nature B.V
• Subjects: Anomalies; Climate; Climate variability; Climatic analysis; Climatology; Coastal management; Coastal zone management; Correlation analysis; Earth and Environmental Science; Earth Sciences; El Nino; El Nino phenomena; El Nino-Southern Oscillation event; Environmental aspects; Geophysics/Geodesy; Gravitational waves; Gravity waves; La Nina; Madden-Julian oscillation; Observations; Ocean currents; Ocean surface; Oceanography; Oceans; Offshore; Significant wave height; Southern Oscillation; Surface gravity waves; Surface wind; Wave analysis; Wave height; Wave parameters; Wave period; Winter; Brazil; Pacific Ocean; Indian Ocean; United States > US; Atlantic Ocean; Climate patterns; Wave climate; El Niño–Southern Oscillation (ENSO); Global wave variability; ENSO–MJO combined activity; Madden–Julian Oscillation (MJO)
• ISSN: 0930-7575; 1432-0894
• DOI: 10.1007/s00382-019-05065-9

The safety of vulnerable coastal and offshore infrastructures requires an in-depth understanding of wave variability and climate drivers. We investigate the association of significant wave height ( H s ) and peak wave period ( T p ) with the co-occurrence of El Niño–Southern Oscillation (ENSO) and the Madden–Julian Oscillation (MJO) at the global scale. We calculate composites of daily anomalies in modelled H s , T p , and surface wind for periods of ENSO–MJO phase combinations. Calculations spanned November–March seasons over the period 1979–2018. Wave anomalies are widespread across the world’s oceans, with remarkable strength during several ENSO–MJO phase combinations, demonstrating strong tropic–tropic and tropic-extratropic teleconnections. Positive H s anomalies are strongest in the Pacific Ocean during El Niño–MJO phase 8, in the Atlantic Ocean during ENSO-neutral-MJO phase 3, and in the Indian Ocean during ENSO-neutral-MJO phase 4. Positive T p anomalies are strongest in the Pacific Ocean during La Niña–MJO phase 8, in the Atlantic Ocean during El Niño–MJO phase 1, and in the Indian Ocean during El Niño–MJO phase 8. In the Southern Ocean, the strongest H s anomalies occur during El Niño–MJO phase 8, whereas in the Maritime Continent, they appear during ENSO-neutral-MJO phases 5–6. Despite previous studies finding low correlations of ENSO indices with wave parameters in the North Atlantic, our results suggest that ENSO-related conditions play a significant role in the area when combined with certain MJO-related conditions. This study also reveals that the wave anomalies associated with ENSO–MJO phase combinations can be twice as strong as those found in previous work, related only to the MJO. Therefore, considering multiple concurrent climate patterns in the analysis of wave anomalies is essential to developing more reliable coastal management plans.