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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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MMS OBSERVATIONS OF INTENSE ELECTRON-SCALE CURRENT SHEETS IN THE EARTH’S MAGNETOTAILтезисы доклада
- Авторы: Leonenko Makar, Grigorenko Elena, Zelenyi Lev, Malova Helmi, Malykhin Andrei, Popov Victor, Buchner Jorg
- Сборник: 44th COSPAR Scientific Assembly - COSPAR 2022, Athens, Greece, 16 - 24 July 2022, Book of abstracts
- Серия: Space Plasmas in the Solar System, including Planetary Magnetospheres (D), D3.5: Magnetotail Dynamics and Substorms during Storm and Non-storm Times
- Тезисы
- Год издания: 2022
- Место издания: COSPAR COSPAR Scientific Assembly Афины Афины Греция
- Первая страница: D3.5-0008-22
- Последняя страница: D3.5-0008-22
- Номер статьи: № 30649
- Аннотация: Flapping of the current sheet (CS) associated with the propagation of high-velocity bulk flowsallowed to observe the super thin current sheet (STCS) in the magnetotail plasma sheet (PS).During the interval of interest, 111 crossings of the CS neutral plane were detected. In 95 crossings,the STCSs with a current density J 20 nA/m2 were observed. A half-thickness (LSTCS)of the STCSs was about a few electron gyroradii or less. In a number of the STCSs the parameterof adiabaticity (e) was <1.0 for suprathermal electron population (>1 keV). Our analysishas shown that the electric current in such STCSs is carried by unmagnetized electrons (kappa_e <1), and the stress balance is supported by the off-diagonal terms of their pressure tensor. Inthis sense, the underlying physics of the formation of STCSs at electron scales by unmagnetized electrons is similar to the mechanism of ion-scale thin CS formation by the quasi-adiabatic ions. The low-energy population of magnetized electrons is also crucially important since it keeps the STCS stable and allows their observation as a quasi-stationary structure. We compare the observed half-thickness of the STCS with that predicted by a new kinetic theory considering the coupling between ion-scale TCS and electron-scale STCS. We found a reasonable agreement between both values: LSTCS (0.3–1)Lambda. Further improvement in the theory taking into account the dynamics of unmagnetized electrons may provide better agreement with observations. Statistical investigations showed that most probably MMS crossed a lot of different STSC, every one of which is associated with some magnetic islands that are moving due to high-velocity bulk flows. We suggested a method for the determination of STCS radial size from magnetic field and configuration data. Calculations have shown that the radial size of STCS can be about a few Earth radius (~ RE). This work is supported by Russian Science Foundation( 20-42-04418).
- Добавил в систему: Малова Хельми Витальевна