LABORATORY MODEL OF A PLANETARY EASTWARD JET
LABORATORY MODEL OF A PLANETARY EASTWARD JET
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DOI：
10.1038/337058a0
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发表时间：
1989-01-05
期刊：
影响因子：
64.8
通讯作者：
SWINNEY, HL
中科院分区：
文献类型：
--
作者：
SOMMERIA, J;MEYERS, SD;SWINNEY, HL
向东的行星流集中成强烈的波浪射流是大气环流（例如，急流）和洋流（例如，哈特拉斯角以东的墨西哥湾流）的主要特征。然而，这些强烈的非线性喷流还没有被很好地理解。在这里，我们描述了一些实验，在这些实验中，我们利用机械力在旋转的环空中产生了类似的射流：科里奥利力作用于从源环向下沉环径向向内泵送的流体，产生了强烈的向东射流。在很宽的参数范围内，射流具有坚固的波浪形状，如图1所示。这些罗斯比波的波速和波长可以用简单的标度参数来表示。向流体中注入染料的实验表明，该喷流对示踪剂的输送起着屏障的作用（见图1e），就像南极极地夜间喷流对臭氧从低纬度向极地地区的输送起着屏障的作用一样1。我们的观察对汇和源的排列细节不敏感。
The concentration of eastward planetary currents into strong wavy jets is a major feature of the atmospheric general circulation (for example, the jet stream) and of oceanic currents (for example, the Gulf Stream east of Cape Hatteras). These strongly nonlinear jets are, however, not well understood. Here we describe experiments in which we have produced similar jets in a rotating annulus with mechanical forcing: the Coriolis force acting on fluid pumped radially inward from a ring of sources to a ring of sinks results in a strong eastward jet. For a wide range of parameters the jet has a robust wavy shape, as shown in Fig. 1. The wave velocity and wavelength of these Rossby waves are accounted for by simple scaling arguments. Experiments with dye injected into the fluid show that the jet acts as a barrier to tracer transport (see Fig. 1e), much as the southern polar night jet may act as a barrier to the transport of ozone from lower latitudes into the polar region1. Our observations are insensitive to the details of the arrangement of the sinks and sources.