Numerical modelling experiments using a flexible-mesh finite-volume approach for the Vanuatu Archipelago

One of the challenges small island developing countries like Vanuatu face as they attempt to understand the impact of climate change, including sea level rise, is a lack of understanding with respect to present-day circulation and sea level variability. While data from satellite observations, and global models offer some insight, the resolution of these data are too coarse to capture island and inter-island variability. In the aftermath of extreme events, one-off local modelling studies of tsunami or storm surge inundation have been undertaken, however there is no systematic ongoing effort to dynamically model these complex regions at scales relevant for coastal planning. In order to better plan for future conditions there is a need for higher resolution modelling efforts covering these under-studied regions. In an attempt to address this need, a flexible mesh finite volume model for the region of Vanuatu was constructed. In this presentation we describe the model setup and methods employed to overcome data gaps. Results from our modelling efforts demonstrate that despite data limitations, useful insights can be gained from leveraging existing data from disparate sources. Insights gained from model simulations can then be used to better target future field research efforts. Given that the impacts of climate change are predicted to disproportionately impact remote Pacific Island communities, intensive efforts such as this study are needed to more accurately replicate current and future oceanic conditions at scales relevant to national, regional and local authorities in this region.