Journal article
Scaling of Ion Bulk Heating in Magnetic Reconnection Outflows for the High-Alfven-speed and Low-β Regime in Earth's Magnetotail
The Astrophysical journal, Vol.971(2), p.144
08/01/2024
DOI: 10.3847/1538-4357/ad6151
Abstract
We survey 20 reconnection outflow events observed by Magnetospheric MultiScale in the low-beta and high-Alfven-speed regime of the Earth's magnetotail to investigate the scaling of ion bulk heating produced by reconnection. The range of inflow Alfven speeds (800-4000 km s(-1)) and inflow ion beta (0.002-1) covered by this study is in a plasma regime that could be applicable to the solar corona and flare environments. We find that the observed ion heating increases with increasing inflow (upstream) Alfven speed, V-A, based on the reconnecting magnetic field and the upstream plasma density. However, ion heating does not increase linearly as a function of available magnetic energy per particle, m(i)V(A)(2). Instead, the heating increases progressively less as m(i)V(A)(2) rises. This is in contrast to a previous study using the same data set, which found that electron heating in this high-Alfven-speed and low-beta regime scales linearly with m(i)V(A)(2), with a scaling factor nearly identical to that found for the low-V-A and high-beta magnetopause. Consequently, the ion-to-electron heating ratio in reconnection exhausts decreases with increasing upstream V-A, suggesting that the energy partition between ions and electrons in reconnection exhausts could be a function of the available magnetic energy per particle. Finally, we find that the observed difference in ion and electron heating scaling may be consistent with the predicted effects of a trapping potential in the exhaust, which enhances electron heating, but reduces ion heating.
Details
- Title: Subtitle
- Scaling of Ion Bulk Heating in Magnetic Reconnection Outflows for the High-Alfven-speed and Low-β Regime in Earth's Magnetotail
- Creators
- M. Oieroset - Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USAT. D. Phan - Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USAJ. F. Drake - Univ Maryland, College Pk, MD 20742 USAM. Starkey - Southwest Research InstituteS. A. Fuselier - Southwest Research InstituteI. J. Cohen - Johns Hopkins Appl Phys Lab, Laurel, MD USAC. C. Haggerty - University of Hawaii SystemM. A. Shay - University of DelawareM. Oka - Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USAD. J. Gershman - NASA Goddard Space Flight Ctr, Greenbelt, MD 20771 USAK. Maheshwari - Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USAJ. L. Burch - Southwest Research InstituteR. B. Torbert - Southwest Research InstituteR. J. Strangeway - Univ Calif Los Angeles, Los Angeles, CA 90095 USA
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.971(2), p.144
- DOI
- 10.3847/1538-4357/ad6151
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- IOP Publishing Ltd
- Number of pages
- 8
- Grant note
- 80NSSC18K1380; 80NSSC20K1781; 80NSSC22K0352; 80NSSC20K0198 / NASA; National Aeronautics & Space Administration (NASA) PHY-2409449 / NSF grant at UC Berkeley PHY2109083 / NSF at the University of Maryland; University of Maryland Baltimore AGS-2024198 / NSF at the University of Delaware; National Science Foundation (NSF) NNG04EB99C / NASA MMS contract (at SWRI)
- Language
- English
- Date published
- 08/01/2024
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9985224318502771
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