New Insights into the Nature of Turbulence in the Earth's Magnetosheath Using Magnetospheric MultiScale Mission DataAustrian Acad Sci, Space Res Inst, Graz, Austria..
Univ Paris Sud, Sorbonne Univ, Ecole Polytech, Lab Phys Plasmas,UMR7648,CNRS, Paris, France..
Univ Paris Sud, Sorbonne Univ, Ecole Polytech, Lab Phys Plasmas,UMR7648,CNRS, Paris, France..
Univ Paris Sud, Sorbonne Univ, Ecole Polytech, Lab Phys Plasmas,UMR7648,CNRS, Paris, France..
Wuhan Univ, Sch Elect & Informat, Beijing, Peoples R China..
NASA, Goddard Space Flight Ctr, Greenbelt, MD USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Univ Colorado, Lab Atmospher & Space Phys, Boulder, CO 80309 USA..
Swedish Inst Space Phys, Uppsala, Sweden..
Swedish Inst Space Phys, Uppsala, Sweden..
Aerosp Corp, Space Sci Dept, El Segundo, CA 90245 USA..
Swedish Inst Space Phys, Uppsala, Sweden..
Swedish Inst Space Phys, Uppsala, Sweden..
Univ Delaware, Newark, DE USA..
Southwest Res Inst, San Antonio, TX USA..
Univ New Hampshire, Durham, NH 03824 USA..
Univ Calif Los Angeles, Los Angeles, CA USA..
Austrian Acad Sci, Space Res Inst, Graz, Austria..
Austrian Acad Sci, Space Res Inst, Graz, Austria..
Univ Paul Sabatier, CNRS UMR5277, IRAP, Toulouse, France..
Southwest Res Inst, San Antonio, TX USA..
Johns Hopkins Univ, Appl Phys Lab, Laurel, MD USA..
Show others and affiliations
2018 (English)In: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 859, no 2, article id 127Article in journal (Refereed) Published
Description
Abstract [en]
The Earth's magnetosheath, which is characterized by highly turbulent fluctuations, is usually divided into two regions of different properties as a function of the angle between the interplanetary magnetic field and the shock normal. In this study, we make use of high-time resolution instruments on board the Magnetospheric MultiScale spacecraft to determine and compare the properties of subsolar magnetosheath turbulence in both regions, i. e., downstream of the quasi-parallel and quasi-perpendicular bow shocks. In particular, we take advantage of the unprecedented temporal resolution of the Fast Plasma Investigation instrument to show the density fluctuations down to sub-ion scales for the first time. We show that the nature of turbulence is highly compressible down to electron scales, particularly in the quasi-parallel magnetosheath. In this region, the magnetic turbulence also shows an inertial (Kolmogorov-like) range, indicating that the fluctuations are not formed locally, in contrast with the quasi-perpendicular magnetosheath. We also show that the electromagnetic turbulence is dominated by electric fluctuations at sub-ion scales (f > 1Hz) and that magnetic and electric spectra steepen at the largest-electron scale. The latter indicates a change in the nature of turbulence at electron scales. Finally, we show that the electric fluctuations around the electron gyrofrequency are mostly parallel in the quasi-perpendicular magnetosheath, where intense whistlers are observed. This result suggests that energy dissipation, plasma heating, and acceleration might be driven by intense electrostatic parallel structures/waves, which can be linked to whistler waves.
Place, publisher, year, edition, pages
IOP PUBLISHING LTD , 2018. Vol. 859, no 2, article id 127
Keywords [en]
acceleration of particles, Earth, planets and satellites: magnetic fields, plasmas, turbulence waves
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-230828DOI: 10.3847/1538-4357/aabae8ISI: 000433938500026Scopus ID: 2-s2.0-85048305743OAI: oai:DiVA.org:kth-230828DiVA, id: diva2:1220645
Note
QC 20180619
2018-06-192018-06-192024-03-15Bibliographically approved