Spatial variability of dune form on Moreton Island, Australia, and its correspondence with wind regime derived from observing stations and reanalyses

Wind regime (speed and direction) are typically highly variable in space and in time. Studies often use a selected meteorological station as representative of a specific dune field. However, wind regime may differ widely even between sites located just a few kilometers apart. In this study we explore wind variability and its relationship to dune morphology on Moreton Island, a dune barrier island located in south-east Queensland, Australia. Using wind data from meteorological stations around Moreton Island and from global and regional reanalyses, we analyzed the correspondence between wind power and wind direction, using the variables of resultant drift potential (RDP) and resultant drift direction (RDD). RDP values were higher in the ocean-facing stations than on the adjacent mainland, and the correspondence of wind regime between the different stations was dependent on both distance from station and on wind magnitude. Ocean facing stations were best correlated with the PRECIS regional reanalysis. Wind regime was found to vary between the ocean and bay sides of Moreton Island, especially in the winter months. Three different slip face orientations (towards the north-west, north and north-east) on Moreton Island were successfully explained based on wind regime and topographic details using data from a LiDAR-derived digital elevation model. We conclude that regional reanalysis models are able to fill in spatial and temporal gaps in wind regime data, necessary for understanding dune form and dune activity.