Inertia-Gravity Waves Generated within a Dipole Vortex
Inertia-Gravity Waves Generated within a Dipole Vortex
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偶极涡旋内产生的惯性重力波
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
Fuqing Zhang
中科院分区：
文献类型：
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作者：
C. Snyder;D. Muraki;R. Plougonven;Fuqing Zhang
涡旋偶极子提供了局域大气喷流的一种简单表示。考虑了具有近似均匀位涡的旋转分层流体中表面势温的天气尺度偶极子的数值模拟。经过一段初始的调整期后，偶极子以近乎稳定的速率和近乎固定的结构沿着一条略微弯曲的轨迹传播了50多天。在急流最大值的下游，气流还包含较小的、向上传播的惯性重力波，这些波嵌入在偶极子内部，相对于偶极子静止不动。这些波沿着偶极子的前缘形成细长的弓形。与水平变形和垂直剪切的传播一致，当波接近偶极子流动的主要滞止点时，波的水平尺度缩小，垂直斜率变化。因为尽管在数值模型中有明显的耗散，但波浪会持续数十天，否则会使…
Abstract Vortex dipoles provide a simple representation of localized atmospheric jets. Numerical simulations of a synoptic-scale dipole in surface potential temperature are considered in a rotating, stratified fluid with approximately uniform potential vorticity. Following an initial period of adjustment, the dipole propagates along a slightly curved trajectory at a nearly steady rate and with a nearly fixed structure for more than 50 days. Downstream from the jet maximum, the flow also contains smaller-scale, upward-propagating inertia–gravity waves that are embedded within and stationary relative to the dipole. The waves form elongated bows along the leading edge of the dipole. Consistent with propagation in horizontal deformation and vertical shear, the waves’ horizontal scale shrinks and the vertical slope varies as they approach the leading stagnation point in the dipole’s flow. Because the waves persist for tens of days despite explicit dissipation in the numerical model that would otherwise damp th...