Investigations Exploring the Use of an Unstructured-Grid, Finite-Volume Modelling Approach to Simulate Coastal Circulation in Remote Island Settings—Case Study Region, Vanuatu/New Caledonia

Understanding coastal circulation and how it may alter in the future is important island settings, especially South West Pacific, where communities rely heavily upon marine resources, sea level rise (SLR) higher than global average. In this study we explore use of an unstructured-mesh finite-volume modelling approach to assist filling knowledge gaps with respect remote locations—selecting Vanuatu New Caledonia archipelagos as our example site. Past limited observations studies are leveraged construct verify a regional/coastal ocean model based on Finite-Volume Community Ocean Model (FVCOM). Following verification tidal behaviour, investigate changes wind speed direction, SLR, water levels currents. Results showed residual was typically associated flow separation at headlands islands. Trade winds had negligible effect coast, however, wind-residual sensitive both direction. Wind-residual currents were strongest close coastlines. Wind patterns strongly influenced by Ekman flow, while blocking, topographic steering geostrophic also appear influence current patterns. Tidal amplitudes phases unchanged due SLR up 2 m, maximum speeds altered much 20 cm/s within some embayments. Non-linear relationships between seen reef platform sites. Under levels, less ±2 which relatively significant given below 10 cm/s. Our findings indicate that under processes governing sediment transport, pollutant dispersal larval transport likely alter, have implications for environments ecosystems. Given subsequent processes, trade climate change act further processes. It felt can be applied other regions help fill critical gaps.