Gridded spring tide current velocity near the east entrance of the Qiongzhou Strait

The SCHISM model uses an unstructured horizontal triangular grid covering the northwestern part of the South China Sea (105–113°E, 16–22°N), with a total of 49,221 nodes and 91,827 elements. The bathymetry in the modeling domain is generated from SRTM15+ [47] with a spatial resolution at 15 arc second and regional digital China Nautical Charts published by the Navigation Guarantee Department of the Chinese Navy Headquarters. The mesh resolution ranged from 200 m in the Qiongzhou Strait to 15 km on the open ocean boundary. There are 40 layers in total with 20 Sigma layers at 40m or shallower water. Z levels of thickness of 5m to 200m were adopted for water depths of 40 to 2200m. The model was verified by the water level time series from the tide gauge stations.