Jian Xing, Zhang Wei, Deng Qiang, Huang Yongxiang
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
Fujian Engineering Research Center for Ocean Remote Sensing Big Data, Xiamen, China" for Yongxiang Huang.
Phys Rev E. 2019 Jun;99(6-1):062122. doi: 10.1103/PhysRevE.99.062122.
In this work, we show that the Tibetan Plateau deformation demonstrates turbulence-like statistics, e.g., spatial invariance across continuous scales. A dual-power-law behavior is evident to show the existence of two possible conservation laws for the enstrophy-like cascade in the range 500≲r≲2000km and kinetic-energy-like cascade in the range 50≲r≲500km. The measured second-order structure-function scaling exponents ζ(2) are similar to their counterparts in the Fourier scaling exponents observed in the atmosphere, where in the latter case the earth's rotation is relevant. The turbulent statistics observed here for nearly zero-Reynolds-number flow can be interpreted by the geostrophic turbulence theory. Moreover, the intermittency correction is recognized with an intensity close to that of the hydrodynamic turbulence of high-Reynolds-number turbulent flows, implying a universal scaling feature of very different turbulent flows. Our results not only shed new light on the debate regarding the mechanism of the Tibetan Plateau deformation but also lead to new challenges for the geodynamic modeling using Newton or non-Newtonian models because the observed turbulence-like features have to be taken into account.
在这项工作中，我们表明青藏高原的变形呈现出类似湍流的统计特征，例如跨连续尺度的空间不变性。双幂律行为明显，表明在500≲r≲2000km范围内存在两种可能的拟涡度级联守恒律，以及在50≲r≲500km范围内存在动能级联守恒律。测量得到的二阶结构函数标度指数ζ(2)与在大气中观测到的傅里叶标度指数中的对应指数相似，在后一种情况下地球自转是相关的。这里观测到的近零雷诺数流动的湍流统计可以用地转湍流理论来解释。此外，间歇性校正被识别出来，其强度接近于高雷诺数湍流流动的流体动力学湍流的强度，这意味着非常不同的湍流流动具有普遍的标度特征。我们的结果不仅为关于青藏高原变形机制的争论提供了新的线索，也给使用牛顿或非牛顿模型的地球动力学建模带来了新的挑战，因为必须考虑观测到的类似湍流的特征。
