Non-Linear Aspects of a Barotropically Unstable Polar Vortex in a Forced-Dissipative System: Flow R
Non-Linear Aspects of a Barotropically Unstable Polar Vortex in a Forced-Dissipative System: Flow R
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强制耗散系统中正压不稳定极涡的非线性方面：流量 R
DOI：
10.2151/jmsj1965.73.2_201
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发表时间：
1995
影响因子：
3.1
通讯作者：
S. Yoden
中科院分区：
文献类型：
--
作者：
K. Ishioka;S. Yoden
本文用高分辨率正压球域模式数值研究了强迫耗散系统中正压不稳定绕极涡旋的非线性动力学。水平运输和混合过程的被动示踪剂也研究了几种类型的不断变化的流场与高分辨率的传输模式。在一定的参数范围内，得到了波动解和不规则解以及稳定波解。在波动中，行星波向东传播，周期性地改变水平结构。逐步过渡从稳定波的解决方案，不规则的，通过摆动被发现的sech型射流，这是不稳定的主要是在极向侧翼的射流，而没有不规则的解决方案，获得一个双曲正切型射流，这是不稳定的赤道侧翼的射流在平流层的实际参数范围内。一个理想的被动示踪剂场的时间演变表明，环极涡旋的边缘是如此强大，通过边缘混合几乎不会发生无论是稳定的解决方案。在sech型射流的不规则解中，流体通过涡边缘的侵入和喷射出现异常的间歇性
Non-linear dynamics of a barotropically unstable circumpolar vortex in a forced-dissipative system is investigated numerically with a high-resolution barotropic model on a spherical domain. Horizontal transport and mixing processes of a passive tracer are also investigated for several types of evolving flow fields with a high-resolution transport model. Vacillating and irregular solutions are obtained within some parameter ranges as well as steady-wave solutions. In the vacillation, planetary waves propagate eastward, changing the horizontal structure pe riodically. Stepwise transitions from steady-wave solutions to irregular ones via vacillations are found for a sech-type jet which is unstable mainly on the poleward flank of the jet, while no irregular solutions are obtained for a tanh-type jet which is unstable on the equatorward flank of the jet within realistic parameter ranges of the stratosphere. Time evolutions of an ideal passive tracer field show that the edge of the circumpolar vortex is so robust that mixing through the edge hardly occurs whether the solution is steady or not. Exceptionally intermittent intrusion and ejection of fluid through the vortex edge occur in the irregular solutions for the sech-type jet