SURFACE QUASI-GEOSTROPHIC DYNAMICS
SURFACE QUASI-GEOSTROPHIC DYNAMICS
复制标题
DOI：
10.1017/s0022112095000012
复制
发表时间：
1995-01-10
影响因子：
3.7
通讯作者：
SWANSON, KL
中科院分区：
文献类型：
--
作者：
HELD, IM;PIERREHUMBERT, RT;SWANSON, KL
具有均匀位涡的准地转流的动力学可归结为水平边界上浮力或位温的演化。在形式上与二维流动相似，表面温度扮演涡量的角色，但流动和平流标量之间的不同关系产生了几个独特的特征。描述了一系列例子，突出了其中的一些特征：椭圆形涡旋的演变;流过山脉时产生的启动涡旋;温度细丝的不稳定性;“边缘波”临界层;以及翻转边缘波中的混合。本文还描述了均匀湍流中示踪剂方差对小尺度的直接级联和反向能量级联的特性。除了它的地球物理相关性，无处不在的二次不稳定性和有限时间崩溃的可能性，使这个系统的一个潜在的重要的，数值上易于处理，湍流理论的试验台。
The dynamics of quasi-geostrophic flow with uniform potential vorticity reduces to the evolution of buoyancy, or potential temperature, on horizontal boundaries. There is a formal resemblance to two-dimensional flow, with surface temperature playing the role of vorticity, but a different relationship between the flow and the advected scalar creates several distinctive features. A series of examples are described which highlight some of these features: the evolution of an elliptical vortex; the start-up vortex shed by flow over a mountain; the instability of temperature filaments; the 'edge wave' critical layer; and mixing in an overturning edge wave. Characteristics of the direct cascade of the tracer variance to small scales in homogeneous turbulence, as well as the inverse energy cascade, are also described. In addition to its geophysical relevance, the ubiquitous generation of secondary instabilities and the possibility of finite-time collapse make this system a potentially important, numerically tractable, testbed for turbulence theories.