Western boundary upwelling dynamics off Oman
Western boundary upwelling dynamics off Oman
复制标题
阿曼附近西部边界上升流动态
DOI：
10.1007/s10236-017-1044-5
复制
发表时间：
2017
期刊：
影响因子：
2.3
通讯作者：
X. Carton
中科院分区：
文献类型：
--
作者：
C. Vic;X. Capet;G. Roullet;X. Carton
尽管它在气候和生态系统方面具有重要意义，但人们对发生在阿曼附近的海岸上升流还没有很好的了解。用原始方程区域模式研究了它的动力学过程，并与著名的东部边界上升流(EBUS)进行了比较。该解与已有的观测结果相比较，较好地模拟了热结构、表面环流(平均和湍流)和海面温度(SST)的季节周期。在上升流有利的风应力旋度强迫的最大值和海洋响应(海面高度和SST的最小值)之间存在1.5个月的滞后，我们将其归因于陆上传播的Rossby波。还模拟了一个西南方向的潜流(与近地表流动方向相反)，其核心深度为1000m，比EBUS中发现的(150-200m)要深得多。EKE预算显示，与EBUS相反，上升流比斜压不稳定更容易产生正压不稳定，局部产生的不稳定对EKE的贡献要高出一个数量级。标准中尺度特征对EKE的平流和再分配也在EKE预算中起着重要作用。
Despite its climatic and ecosystemic significance, the coastal upwelling that takes place off Oman is not well understood. A primitive-equation, regional model forced by climatological wind stress is used to investigate its dynamics and to compare it with the better-known Eastern Boundary Upwellings (EBUs). The solution compares favorably with existing observations, simulating well the seasonal cycles of thermal structure, surface circulation (mean and turbulent), and sea-surface temperature (SST). There is a 1.5-month lag between the maximum of the upwelling-favorable wind-stress-curl forcing and the oceanic response (minima in sea-surface height and SST), which we attribute to onshore-propagating Rossby waves. A southwestward-flowing undercurrent (opposite to the direction of the near-surface flow) is also simulated with a core depth of 1000 m, much deeper than found in EBUs (150–200 m). An EKE budget reveals that, in contrast to EBUs, the upwelling jet is more prone to barotropic than baroclinic instability and the contribution of locally-generated instabilities to EKE is higher by an order of magnitude. Advection and redistribution of EKE by standing mesoscale features also play a significant role in EKE budget.