...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Physical Oceanography >The Response of the North Pacific Ocean to Decadal Variability in Atmospheric Forcing: Wind versus Buoyancy Forcing
【24h】

The Response of the North Pacific Ocean to Decadal Variability in Atmospheric Forcing: Wind versus Buoyancy Forcing

机译：北太平洋对大气强迫年代际变化的响应：风与浮力强迫

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Both wind and buoyancy forcing result in variability in the North Pacific Ocean thermocline. A vertical modal analysis of the density deviations in a 30-yr run of an ocean general circulation model of the North Pacific forced by atmospheric variability is used to identify the spatial and temporal patterns of the different baroclinic modes. The different dynamic vertical modes show distinct propagation characteristics, with the first baroclinic mode exhibiting consistent westward propagation at all latitudes. The higher baroclinic modes show westward phase propagation at low latitudes but propagate eastward at higher latitudes. The propagation characteristics of each mode can be understood by the inclusion of the zonal mean flow in the vertical structure equation. Evaluation of the Ekman pumping and diapycnal fluxes in the quasigeostrophic potential vorticity equation for each dynamic vertical mode distinguishes their effects on the thermocline variability. Wind variability dominantly forces the first baroclinic mode response while buoyancy forcing results in a higher baroclinic mode response. Two additional numerical model runs, one with climatological wind stress and one with climatological heat fluxes and SST, demonstrate the relative roles of Ekman pumping and diabatic pumping on the forcing of each vertical mode. Ekman pumping is important throughout the North Pacific for forcing first-mode variability. Diabatic pumping, or that associated with thermal forcing, is important in the Kuroshio Extension and much less so farther to the south and can act to suppress the first-baroclinic-mode Ekman pumping response. The second baroclinic mode has a band of positive energy emanating westward from the eastward end of the Kuroshio Extension and ending at the western boundary at 20°N, reflecting the strong effect of the mean flow on wave propagation of the higher baroclinic modes. Mode coupling also occurs, especially in the westward return flow of the subtropical gyre. The results are shown to be consistent with the one-dimensional wave equation and show the importance of inclusion of the first several baroclinic modes in studies of the decadal variability in the ocean.
机译：风和浮力的强迫都会导致北太平洋温跃层的变化。在大气变率的作用下，对北太平洋海洋总环流模型运行30年的密度偏差进行了垂直模态分析，以识别不同斜压模式的时空格局。不同的动态垂直模式显示出不同的传播特性，第一个斜斜模式在所有纬度上都表现出一致的向西传播。较高的斜压模式在低纬度显示出向西传播，而在高纬度显示出向东传播。可以通过在垂直结构方程中包含区域平均流量来理解每种模式的传播特性。对每种动态垂直模式的准地转势涡度方程中的埃克曼泵浦和渗流通量进行评估，可以区分它们对温跃层变异性的影响。风的可变性主要强迫第一斜压模响应，而浮力强迫导致较高的斜压模响应。另外两个数值模型运行，一个具有气候风应力，另一个具有气候热通量和SST，证明了埃克曼抽水和非绝热抽水在每种垂直模式强迫下的相对作用。在整个北太平洋，埃克曼抽水对于强迫第一模式变化是很重要的。绝热抽吸或与热强迫相关的绝热抽吸在黑潮扩展中很重要，向南越远则越少，并且可以起到抑制第一斜压模式埃克曼抽吸响应的作用。第二斜压模式具有从黑潮延伸区的东端向西发出并在20°N的西边界处终止的正能量带，反映了平均流量对较高斜压模式的波传播的强烈影响。也会发生模式耦合，特别是在副热带回旋的向西回流中。结果表明，该结果与一维波动方程是一致的，并且表明了在海洋年代际变化研究中包括前几种斜压模式的重要性。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号