Hydrodynamics at the whole of Great Barrier Reef scale (MTSRF Project 2.5i.1)

A three-dimensional whole-of-GBR baroclinic hydrodynamic model was applied at a spatial resolution of between 1 and 4 km. The model simulations are compiled to examine the intensity, duration and frequency of different lower salinity events. Return periods are then calculated from the annual frequency of such events.The model includes the factors affecting currents, mixing, temperature and salinity within the GBR lagoon and exchanges with the adjacent Coral Sea: river discharge, time-series wind, tidal.Accurate boundary forcing for offshore ocean boundaries was provided by a global, data-assimilating, eddy-resolving model. To allow future development of other essential aspects of a large-scale water quality model for the GBR, particularly sediment dynamics and biogeochemical components. To test this model and strengthen the likelihood of future predictions, a hindcast was made of circulation within the GBR lagoon during the 2009 wet season, including prediction of the trajectories and spatial distribution of major freshwater inflows during this period.

本研究采用空间分辨率为1~4千米的大堡礁（Great Barrier Reef, GBR）全域三维斜压水动力模型，通过数值模拟分析不同低盐水事件的强度、持续时长与发生频率，并基于此类事件的年发生频次计算其重现期。该模型涵盖了影响大堡礁潟湖内流场、混合过程、温度与盐度，以及与邻近珊瑚海（Coral Sea）水交换的各类关键因子：河流径流量、时序风场与潮汐动力。离岸海洋边界的精准强迫场由一套全球数据同化涡旋解析模型提供。为支撑后续大堡礁大型水质模型其他核心模块的开发（尤其是泥沙动力学与生物地球化学组分模块），同时验证本模型并提升未来预测的可靠性，本研究针对2009年湿季期间大堡礁潟湖的环流过程开展了后报模拟，同步重现了该时段内主要淡水输入的运移路径与空间分布特征。