Barotropic tides on the southeast New England shelf : a view from a hybrid data assimilative modeling approach
Barotropic tides on the southeast New England shelf : a view from a hybrid data assimilative modeling approach
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DOI：
10.1029/2005jc003254
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发表时间：
2006-08
影响因子：
--
通讯作者：
R. He;J. Wilkin
中科院分区：
文献类型：
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作者：
R. He;J. Wilkin
[1]利用高分辨率混合资料同化(DA)模式系统研究了新英格兰东南部陆架的正压潮汐和潮汐动力学。现场观测包括由沿海海平面和海底压力计分析的5个主要潮汐分量[M2、S2、N2、O1和K1]的潮汐调和。DA系统由正反两个模型组成。前者是三维、有限差分、非线性区域海洋模拟系统(ROMS)。后者是三维线性化的频域有限元模型Truxton。DA系统通过正压潮汐开放边界条件(OBC)的反演同化现场观测。通过比较观测到的潮汐调和和模拟的潮汐调和之间的不匹配来评价模型技巧。同化方案在改正潮汐OBC方面是有效和高效的，而潮汐OBC反过来又改善了ROMS潮汐解。反数据同化后，模型/数据失配减少了50%。生成了5个潮汐分量的共幅和共相位图以及潮流椭圆，揭示了东北潮汐放大的缅因湾和西南部潮汐能量低得多的中大西洋海湾之间过渡区域的复杂潮汐变异性。对M2潮剩余环流、能量和动量平衡的详细研究表明，南塔基特浅滩独特的海底测深和复杂的海岸几何形状在影响区域潮汐动力学方面发挥了关键作用。
[1] A high-resolution hybrid data assimilative (DA) modeling system is used to study barotropic tides and tidal dynamics on the southeast New England shelf. In situ observations include tidal harmonics of 5 major tidal constituents [M2, S2, N2, O1, and K1] analyzed from coastal sea level and bottom pressure gauges. The DA system consists of both forward and inverse models. The former is the three-dimensional, finite difference, nonlinear Regional Ocean Modeling System (ROMS). The latter is a three-dimensional linearized, frequency domain, finite element model TRUXTON. The DA system assimilates in situ observations via the inversion for the barotropic tidal open boundary conditions (OBCs). Model skill is evaluated by comparing the misfits between the observed and modeled tidal harmonics. The assimilation scheme is found effective and efficient in correcting the tidal OBCs, which in turn improve ROMS tidal solutions. Up to 50% decreases of model/data misfits are achieved after inverse data assimilation. Co-amplitude and co-phase maps and tidal current ellipses for each of 5 tidal constituents are generated, revealing complex tidal variability in this transition region between the tidally amplified Gulf of Maine in the northeast and the tidally much less energetic Middle Atlantic Bight in the southwest. Detailed examinations on the residual circulation, energetics, and momentum balances of the M2 tide reveal the key roles of the unique bottom bathymetry of Nantucket Shoals and the complex coastal geometry in affecting the regional tidal dynamics.