Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92093.
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91106.
Proc Natl Acad Sci U S A. 2022 Apr 26;119(17):e2120486119. doi: 10.1073/pnas.2120486119. Epub 2022 Apr 19.
Vortex crystals are quasiregular arrays of like-signed vortices in solid-body rotation embedded within a uniform background of weaker vorticity. Vortex crystals are observed at the poles of Jupiter and in laboratory experiments with magnetized electron plasmas in axisymmetric geometries. We show that vortex crystals form from the free evolution of randomly excited two-dimensional turbulence on an idealized polar cap. Once formed, the crystals are long lived and survive until the end of the simulations (300 crystal-rotation periods). We identify a fundamental length scale, Lγ=(U/γ)1/3, characterizing the size of the crystal in terms of the mean-square velocity U of the fluid and the polar parameter γ=fp/a2p, with fp the Coriolis parameter at the pole and ap the polar radius of the planet.
涡旋晶体是在均匀的弱涡度背景中嵌入的具有相同符号的涡旋的准正则阵列，存在于固体旋转体中。在木星的极区和轴对称几何形状的磁化电子等离子体的实验室实验中观察到涡旋晶体。我们表明，涡旋晶体是由理想极区上随机激发的二维湍流的自由演化形成的。一旦形成，晶体的寿命很长，可以持续到模拟结束（300 个晶体旋转周期）。我们确定了一个基本长度尺度 Lγ=(U/γ)1/3，该尺度根据流体的均方速度 U 和极参数γ=fp/a2p 来表示晶体的大小，其中 fp 是极点处的科里奥利参数，ap 是行星的极半径。
