Application Of ELCIRC Model In Changjiang Estuary

Due to the lack of open-source marine models sufficiently addressing estuary-shelf systems pose cross-scale modeling challenges, this paper will adopt a new model ELCIRC to check its applicability in Changjiang Estuary.ELCIRC(Eulerian — Lagrangian CIRCulation) is an unstructured-grid model designed for the effective simulation of 3D baroclinic circulation across river-to-ocean scales. It uses a finite-volume/finite-difference Eulerian-Lagrangian algorithm to solve the shallow water equations, written to realistically address a wide range of physical processes and of atmospheric, ocean and river forcings. The numerical algorithm is low-order, but volume conservative, stable and computationally efficient. It also naturally incorporates wetting and drying of tidal flats, and allows for the use of state-of-the-art turbulence closure schemes and solver methods.The theory and application is explained in this paper. Software XMGREDIT5 matching ELCIRC is used to generate unstructured grid, and is considered fit for ocean but rivers. Tidal current is simulated and validated well, and sensitivity of current structure to bathymetry is visible. Affection of wind is qualitatively analyzed here. At the same time the model is improved on as required, like the tidal open boundary which could choose not only long period harmonic constant but also short period harmonic constant and tidal level, and multi-point results and flow field data could be exported effectively with binary results.The characteristics are evaluated and on-going developments are given. ELCIRCcould be applied in Changjiang Estuary or larger region, but accession of sedimentmodule could be the leading work in the application.