Atmosphere-Ocean Processes Governing Inflow to the Northern Caribbean Sea

Abstract

Near-surface currents entering the northern Caribbean from the Atlantic are described using ocean reanalysis at monthly to daily timescales, underpinned by satellite data assimilation. Statistical analyses involved spatial clustering into current vector modes with associated time scores for quantifying spectral power and regression onto atmospheric fields. Inflow across the Anegada, Mona, Windward (AMW) Passages peaks at ~100 m depth at ~0.2 m/s during summer and pulses at periods of 45, 100, and 365 days, and at 3, 6.5 years. The intra-seasonal periods may relate to Madden–Julian Oscillations and westward ocean Rossby waves, while inter-annual periods associate with regional climate anomalies. An empirical orthogonal function analysis demonstrates that AMW inflow varies across multiple timescales and is enhanced when the subtropical high-pressure ridge penetrates into the western Caribbean. A case study reveals key features during a surge of inflow to the northern Caribbean. Marine climate change involves heat advected poleward by currents along the western edge of the tropical Atlantic, fed through the Caribbean Sea. Consequently, the study of inflows garners wide interest.