Residence time in lagoons on the coast of Virginia, 2002 and 2009

To better understand the factors controlling residence time and exchange in coastal bays, a three-dimensional finite-volume coastal ocean model (FVCOM) was set up, validated with field observations, and used to calculate residence times in a system of 14 shallow coastal bays on the Atlantic coast of the USA (Virginia Coast Reserve). Simulations were run using measured tide and with & without wind forcing for November 2002-January 2003 and January-March 2009. Residence times are determined by tracking a large number of neutrally buoyant particles in the FVCOM simulations. Particles were released each high and low tide for the first 30 days of the simulations (30 high-tide and 30 low-tide releases). Each value of residence time is the average elapsed time from when a particle was released to when it exited through an inlet to the ocean. Each line of the table corresponds to a site where particles were released.

为深入探究控制近岸海湾滞留时间与水交换过程的影响机制，本研究构建了三维有限体积近岸海洋模型（FVCOM），并通过现场观测数据对模型进行验证；随后将该模型应用于美国大西洋沿岸的弗吉尼亚海岸保护区（Virginia Coast Reserve）内由14个浅海近岸海湾组成的系统，以计算各海湾的滞留时间。模拟实验基于实测潮汐数据开展，分别设置有风强迫与无风强迫两种工况，覆盖2002年11月至2003年1月、2009年1月至3月两个研究时段。本研究通过在FVCOM模拟中追踪大量中性浮粒来确定滞留时间：在模拟的前30天内，于每次涨潮与落潮时刻分别释放浮粒，累计完成30次涨潮释放与30次落潮释放。单条滞留时间数值为浮粒从释放至通过海湾入口汇入大洋的平均历时。表格中的每一行对应一次浮粒释放的布设站点。