EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Identification of Kelvin-Helmholtz vortices at the Earth’s magnetosphere

Adriana Settino1,2, Denise Perrone3, Yuri V. Khotyaintsev2, Daniel B. Graham2, Oreste Pezzi4,5,6, Francesco Malara1, and Francesco Valentini1
Adriana Settino et al.
  • 1Dipartimento di Fisica, Università della Calabria, 87036 Rende (CS), Italy
  • 2Swedish Institute of Space Physics, Box 537 SE--751 21 Uppsala, Sweden
  • 3ASI – Italian Space Agency, via del Politecnico snc, 00133 Rome, Italy
  • 4Gran Sasso Science Institute, I-67100 L’Aquila, Italy
  • 5INFN/Laboratori Nazionali del Gran Sasso, I-67100 Assergi (AQ), Italy
  • 6Istituto per la Scienza e Tecnologia dei Plasmi, CNR, Via Amendola 122/D, I-70126 Bari, Italy

Kelvin-Helmholtz instability is a widespread phenomenon in space plasmas, such as at the planetary magnetospheres. During its nonlinear phase, the generation of Kelvin-Helmholtz vortices takes place. The identification of such coherent structures is not straightforward in observational data contrary to numerical simulations where both temporal evolution and spatial behavior can be observed. Recently, a comparison between a hybrid Vlasov-Maxwell simulation and Magnetospheric Multi-Scale satellites observation of a Kelvin-Helmholtz event has shown the presence of kinetic features that can uniquely characterize the boundaries of Kelvin-Helmholtz vortices.  Indeed, a strong total current density has been observed in correspondence of the edges of each vortex associated with a weakly distorted distribution function from the equilibrium distribution; while the opposite occurs inside the vortex region. Moreover, a new tool has been proposed to distinguish the different phases of the Kelvin-Helmholtz instability and to identify the trajectory of the spacecraft across the vortex itself. Such a tool takes into consideration the mixing degree between the magnetospheric-like and magnetosheath-like particles population in the Earth environment. The clear identification of a vortex in in situ data is an important achievement since it can provide a better understanding of the role that Kelvin-Helmholtz instability plays in weakly collisional space plasmas in the contest of energy dissipation.

This work has received funding from the European Unions Horizon 2020 research and innovation programme under grant agreement no. 776262 (AIDA,).

How to cite: Settino, A., Perrone, D., Khotyaintsev, Y. V., Graham, D. B., Pezzi, O., Malara, F., and Valentini, F.: Identification of Kelvin-Helmholtz vortices at the Earth’s magnetosphere, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9912,, 2021.


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