Program     Physics of estuaries and coastal seas       Poster Adjustment of Changjiang River plume front during downwelling-favorable wind events P-P1-10-S Runqing Lv* , Xiamen University Peng Cheng, Xiamen University Presenter Email: 22320161151281@stu.xmu.edu.cn River plume is an important phenomenon in the estuary region, which is affected by various factors, and plays vital role in near-shore sediment transport and bio-distribution. The front of river plume is a barrier to astrict the nutritional materials to the ocean and downwelling-favorable wind is supposed to be a mechanism to break out the barrier effect. An analysis with 3D numerical idealized model indicated that river plume front underwent destratification stage and restratification stage with downwelling-favorable wind. Meanwhile, symmetric instability developed in the frontal region due to the continuous along-shelf buoyancy flux. Based on the previous idealized model, a verification with a realistic model is necessary. In this post, we took an example of Changjiang river plume, which is always suffered from downwelling-favorable wind during winter time monsoon, to confirm the idealized result, using the Regional Ocean Modeling System (ROMS). The model was set with a realistic topography and a boundary condition from HYCOM. Both the tidal and atmospheric forcing were considered. The result exhibited that similar adjustment of plume front developed in the Changjiang river plume during a downwelling-favorable wind event. Within a northwest wind case, the front firstly became well-mixed and then restratified. The parameter calculation for the plume front also showed the evolution of symmetric instability. Moreover, a series of sensitive experiments were applied with the realistic model, which confirmed that the along-shelf buoyancy flux and wind forcing were the major factors for the front adjustments.

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