Analysis of flow variability in the Yucatan Channel
Analysis of flow variability in the Yucatan Channel
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尤卡坦海峡流量变化分析
DOI：
10.1029/2003jc001922
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发表时间：
2003
影响因子：
--
通讯作者：
A. Badan
中科院分区：
文献类型：
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作者：
A. Abascal;J. Sheinbaum;J. Candela;J. Ochoa;A. Badan
[1]利用1999年8月至2000年6月部署的8个系泊阵列的数据，分析了尤卡坦海峡速度场和温度场的结构和变化。面积平均动能和运输波动谱表明，这些量的极值不一致，流量的变化是由高能量的过程与弱运输的贡献。输送波动在20-40和5-10天周期带中达到峰值，但与局地风应力强迫没有明显的相关性。沿通道速度分量的经验正交函数（ERF）分析表明，约55%的总速度方差保留在前两个EOF中，这两个EOF描绘了三极（通道中心与两侧异相）和偶极结构。低通温度和速度分量的多元复分析表明，三极-偶极子结构的不规则振荡的流量，有关的反气旋和气旋通过通道的西北传播的组件。在这些模式中的弱传输信号是一致的涡被平流的平均流。与其他西部边界电流区域相比，涡流的通过提供了尤卡坦海峡的变化的主要解释。然而，控制运输变异性的过程仍然不清楚。
[1] The structure and variability of the velocity and temperature fields in Yucatan Channel are analyzed using data from an eight-mooring array deployed from August 1999 to June 2000. The area-averaged kinetic energy and transport fluctuations spectra show that the extrema of these quantities do not coincide, and that flow variability is dominated by highly energetic processes with weak transport contributions. Transport fluctuations peak in the 20–40 and 5–10 day period bands, but show no clear correlation with the local wind-stress forcing. Empirical orthogonal function (EOF) analysis of the along-channel velocity component shows that approximately 55% of the total velocity variance is retained in the first two EOFs, which depict tripolar (the center of the channel is out of phase with the sides) and dipolar structures. A multivariate complex EOF analysis of low-passed temperature and velocity components suggests the tripole-dipole structures are the components of irregular oscillations of the flow, related to the northwestward propagation of anticyclones and cyclones through the channel. The weak transport signal in these modes is consistent with the eddies being advected by the mean flow. In contrast to other western boundary current regions, the passage of eddies provides the predominant explanation for the variability in the Yucatan Channel. However, the processes controlling transport variability remain unclear.