Kelvin–Helmholtz‐Related Turbulent Heating at Saturn's Magnetopause Boundary
Kelvin–Helmholtz‐Related Turbulent Heating at Saturn's Magnetopause Boundary
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DOI：
10.1029/2020ja028479
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发表时间：
2021-02
期刊：
影响因子：
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通讯作者：
P. Delamere;C. Ng;P. Damiano;B. Neupane;J. Johnson;B. Burkholder;Xuanye Ma;K. Nykyri
中科院分区：
文献类型：
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作者：
P. Delamere;C. Ng;P. Damiano;B. Neupane;J. Johnson;B. Burkholder;Xuanye Ma;K. Nykyri
巨行星磁层的重大挑战问题之一是非绝热等离子体加热问题。简单的湍流加热模型考虑从一个尺度到另一个尺度的能量级联率，其中能量密度基于反向传播的阿尔文波的垂直磁波动。从湍流理论的加热率密度的分析表达式已经产生了有希望的结果，在木星和土星观测到的离子加热。在这里，我们比较离子加热的混合模拟的开尔文-亥姆霍兹不稳定性和分析估计，以验证湍流理论，并进一步了解离子加热的性质。在我们的三维开尔文-亥姆霍兹模拟中，在非线性生长阶段产生了10−15 W/m3的加热速率密度，并与分析估计相比较。以土星为目标的结果将在快速旋转的磁层中径向等离子体传输的更广泛背景下进行讨论。
One of the grand challenge problems of the giant planet magnetospheres is the issue of nonadiabatic plasma heating. Simple turbulent heating models consider the energy cascade rate from one scale to another where the energy density is based on perpendicular magnetic fluctuations of counterpropagating Alfvén waves. Analytical expressions from turbulence theory for the heating rate density have yielded promising results for the observed ion heating at Jupiter and Saturn. Here, we compare ion heating using hybrid simulations of the Kelvin–Helmholtz instability and analytical estimates in an effort to validate turbulence theory and further understand the nature of the ion heating. Heating rate densities ∼10−15 W/m3 are produced in our three‐dimensional Kelvin–Helmholtz simulations during the nonlinear growth phase and compare favorably with analytical estimates. Results targeting Saturn will be discussed in the broader context of radial plasma transport in the rapidly rotating magnetospheres.