In Situ Observation of Intermittent Dissipation at Kinetic Scales in the Earth's Magnetosheath Visa övriga samt affilieringar
2018 (Engelska) Ingår i: Astrophysical Journal Letters, ISSN 2041-8205, E-ISSN 2041-8213, Vol. 856, nr 1, artikel-id L19Artikel i tidskrift (Refereegranskat) Published
Abstract [en]
We present a study of signatures of energy dissipation at kinetic scales in plasma turbulence based on observations by the Magnetospheric Multiscale mission (MMS) in the Earth's magnetosheath. Using several intervals, and taking advantage of the high-resolution instrumentation on board MMS, we compute and discuss several statistical measures of coherent structures and heating associated with electrons, at previously unattainable scales in space and time. We use the multi-spacecraft Partial Variance of Increments (PVI) technique to study the intermittent structure of the magnetic field. Furthermore, we examine a measure of dissipation and its behavior with respect to the PVI as well as the current density. Additionally, we analyze the evolution of the anisotropic electron temperature and non-Maxwellian features of the particle distribution function. From these diagnostics emerges strong statistical evidence that electrons are preferentially heated in subproton-scale regions of strong electric current density, and this heating is preferentially in the parallel direction relative to the local magnetic field. Accordingly, the conversion of magnetic energy into electron kinetic energy occurs more strongly in regions of stronger current density, a finding consistent with several kinetic plasma simulation studies and hinted at by prior studies using lower resolution Cluster observations.
Ort, förlag, år, upplaga, sidor Institute of Physics Publishing , 2018. Vol. 856, nr 1, artikel-id L19
Nyckelord [en]
acceleration of particles, magnetic reconnection, plasmas, turbulence, waves
Nationell ämneskategori
Fysik
Identifikatorer URN: urn:nbn:se:kth:diva-227386 DOI: 10.3847/2041-8213/aaadf8 ISI: 000428392300010 Scopus ID: 2-s2.0-85044712986 OAI: oai:DiVA.org:kth-227386 DiVA, id: diva2:1211153
Anmärkning Export Date: 9 May 2018; Article; Funding details: AGS-1460130; Funding details: MMS, Massachusetts Medical Society; Funding details: UD, University of Delaware; Funding details: NNX14AC39G, NASA, National Aeronautics and Space Administration; Funding details: NNX17AB79G; Funding details: 11672123, NSFC, National Natural Science Foundation of China; Funding details: 91752201, NSFC, National Natural Science Foundation of China; Funding details: NSFC, National Natural Science Foundation of China; Funding text: This research partially supported by the MMS mission through NASA grant NNX14AC39G at the University of Delaware, by NASA LWS grant NNX17AB79G, and in part by NSF-SHINE AGS-1460130. A.C. is supported by the NASA grants. W.H.M. is a member of the MMS Theory and Modeling team. M.W. acknowledges the support from the National Natural Science Foundation of China (NSFC grant Nos. 11672123 and 91752201). We are grateful to the MMS instrument teams, especially SDC, FPI, and FIELDS, for cooperation and collaboration in preparing the data. The data used in this analysis are Level 2 FIELDS and FPI data products, in cooperation with the instrument teams and in accordance their guidelines. All MMS data are available athttps://lasp.colorado.edu/mms/sdc/. QC 20180530
2018-05-302018-05-302022-06-26 Bibliografiskt granskad