Interannual variability of wave climate in the Caribbean Sea

Low-frequency interannual climatic oscillations have been reported to influence the precipitation regimes, river discharges, winds, and sea level in the Caribbean Sea. Here, we analyzed the presence and relevance of low-frequency oscillations in the waves' climate of the Caribbean Sea using data from WAVEWATCH III (NOAA) reanalysis and applying frequency domain wavelet transform technique. Results show a clear sectorization of the Caribbean Sea according to the presence and relevance of interannual oscillations in wave climate, where the southwestern region (Colombian basin) exhibits a larger number of statistically significant oscillations (at 95% confidence levels) with recurrence periods of 2-4, 4-8, and 8-12 years. Only some of these frequencies are observed in the rest of Caribbean basin. Two climatic events occurring in the periods 1997-1998 and 2010-2011 stand out in the study zone for their high energy in wavelet analysis. These events have been associated with the occurrence of the warm and cold phases of the El Nino Southern Oscillation (ENSO), respectively, and are well known due to their strong global effects on hydroclimatology. Thus, an additional analysis was performed in the time domain to investigate the effect of the two events on Caribbean Sea waves. The results revealed an influence of ENSO on significant wave height and peak period comparing with multi-year average conditions, producing highly variable spatial and temporal wave patterns, with more evident effects during the cold phase of ENSO (La Nina). These results confirm the sectorization of the Caribbean Sea regarding the energy and interannual variability of waves.