Development of a regional ocean model for the Caribbean, including 3D dynamics, thermodynamics and full surface flux forcing

A regional ocean model based on the NEMO framework was developed for the Caribbean. The model includes tides, lateral boundary forcing from a global simulation, realistic thermodynamics and baroclinic dynamics, and atmospheric forcing from the ECMWF ERA5 reanalysis. A simulation of the year 2010 (with spin-up over 2009) was performed and the model was validated against sea-level observations from tide gauges and sea surface temperature observations from satellite. Typical temporal RMS error in sea-level is 6-8 cm and spatial RMS error in time-mean SST is 0.53 degC, with a mean offset of 0.08 degC but with localised regional extremes of up to +/- 3 deg C. Hurricanes Igor and Tomas show only a weak signature, with less than 20 cm storm surge, in both the tide gauge observations and model data for the three sites examined in the eastern Caribbean. Greater sea-level impacts experienced from these hurricanes are likely to have been due to high-frequency surface wind-waves and swell, which are not present in the tide gauge observations and are not simulated, nor parameterised, in this version of the model. These processes should be considered in addition. Further impacts may have not been directly related to sea level, e.g. landslides due to heavy rainfall and winds