ABSTRACT The exchange of energy and momentum between the Earth’s upper atmosphere and ionosphere, and its space environment (magnetosphere) is regulated by electric currents (called

Birkeland currents) flowing along magnetic field lines that connect these two regions of space1. The associated electric currents flow towards and away from each pole primarily in two

concentric conical sheets2. It has been expected that powerful sheets of magnetic-field-aligned electric currents would be found in association with the bright Jovian auroras3. The Juno

spacecraft is well positioned to explore Jupiter’s polar magnetosphere and sample Birkeland or field-aligned currents and particle distributions. Since July 2016, Juno has maintained a

during Juno’s transits of Jupiter’s polar regions, and thereby demonstrate Birkeland currents associated with Jupiter’s auroral emissions. We characterize the magnitude and spatial extent of

the currents and we find that they are weaker than anticipated and filamentary in nature. A significant asymmetry is observed between the field perturbations and the current associated with

the northern and the southern auroras. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS Access through

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customer support SIMILAR CONTENT BEING VIEWED BY OTHERS TWO DISTINCT CURRENT SYSTEMS IN THE IONOSPHERE OF MARS Article Open access 09 November 2024 IN SITU EVIDENCE OF THE MAGNETOSPHERIC

CUSP OF JUPITER FROM JUNO SPACECRAFT MEASUREMENTS Article Open access 18 July 2024 ENERGETIC NEUTRAL ATOM IMAGING REVEALS NEARLY 11-YEAR CYCLE OF THE RING CURRENT OF SATURN Article Open

access 05 December 2024 DATA AVAILABILITY The Juno magnetometer data used in this study will be made available through the NASA Planetary Data System (https://pds.nasa.gov) in accordance

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498–504 (Cambridge Planetary Science Old, 1983). Download references ACKNOWLEDGEMENTS S.K. thanks F. Bagenal for the motivation and valuable scientific discussions in relation to this paper.

All authors acknowledge support from the Juno project. E.J.B. was supported by STFC grant ST/N000749/1 and a Royal Society Wolfson Research Merit Award. AUTHOR INFORMATION AUTHORS AND

AFFILIATIONS * NASA Goddard Space Flight Center, Greenbelt, MD, USA Stavros Kotsiaros, John E. P. Connerney, Daniel J. Gershman & Yasmina M. Martos * University of Maryland College Park,

College Park, MD, USA Stavros Kotsiaros & Yasmina M. Martos * Space Research Corporation, Annapolis, MD, USA John E. P. Connerney * Johns Hopkins University Applied Physics Laboratory,

Laurel, MD, USA George Clark & Barry H. Mauk * Southwest Research Institute, San Antonio, TX, USA Frederic Allegrini, G. Randall Gladstone, Thomas K. Greathouse & Scott J. Bolton *

Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA Frederic Allegrini & G. Randall Gladstone * Department of Physics and Astronomy, University

of Iowa, Iowa City, IA, USA William S. Kurth * Universität zu Köln, Institut für Geophysik und Meteorologie, Cologne, Germany Joachim Saur * Department of Physics and Astronomy, University

of Leicester, Leicester, UK Emma J. Bunce * Jet Propulsion Laboratory, Pasadena, CA, USA Steven M. Levin Authors * Stavros Kotsiaros View author publications You can also search for this

author inPubMed Google Scholar * John E. P. Connerney View author publications You can also search for this author inPubMed Google Scholar * George Clark View author publications You can

also search for this author inPubMed Google Scholar * Frederic Allegrini View author publications You can also search for this author inPubMed Google Scholar * G. Randall Gladstone View

author publications You can also search for this author inPubMed Google Scholar * William S. Kurth View author publications You can also search for this author inPubMed Google Scholar *

Barry H. Mauk View author publications You can also search for this author inPubMed Google Scholar * Joachim Saur View author publications You can also search for this author inPubMed Google

Scholar * Emma J. Bunce View author publications You can also search for this author inPubMed Google Scholar * Daniel J. Gershman View author publications You can also search for this

author inPubMed Google Scholar * Yasmina M. Martos View author publications You can also search for this author inPubMed Google Scholar * Thomas K. Greathouse View author publications You

can also search for this author inPubMed Google Scholar * Scott J. Bolton View author publications You can also search for this author inPubMed Google Scholar * Steven M. Levin View author

publications You can also search for this author inPubMed Google Scholar CONTRIBUTIONS S.K. wrote the manuscript and performed the magnetic field data analysis. J.E.P.C. contributed to the

discussions of the data analysis and assisted with the writing of the manuscript. G.C. and F.A. performed the data analysis of the JEDI and JADE instruments and contributed to Fig. 3 of the

manuscript. G.R.G. performed the data analysis of the UVS instrument and contributed to Fig. 1 of the manuscript. W.S.K. performed the data analysis of the Waves instrument and contributed

to Supplementary Fig. 2 of the manuscript. D.J.G. contributed to the magnetic field data calibration and the discussions of the data analysis. B.H.M., T.K.G and Y.M.M. contributed to the

discussions of the data analysis. J.S. and E.J.B. contributed to the discussions of the physics of the Birkeland currents and the data analysis. S.J.B. is the principal investigator of the

mission and S.M.L. is the project scientist of the mission. CORRESPONDING AUTHOR Correspondence to Stavros Kotsiaros. ETHICS DECLARATIONS COMPETING INTERESTS The authors declare no competing

interests. ADDITIONAL INFORMATION PUBLISHER’S NOTE: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. SUPPLEMENTARY

INFORMATION SUPPLEMENTARY INFORMATION Supplementary Figs. 1–3 and Supplementary reference 1. RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Kotsiaros,

S., Connerney, J.E.P., Clark, G. _et al._ Birkeland currents in Jupiter’s magnetosphere observed by the polar-orbiting Juno spacecraft. _Nat Astron_ 3, 904–909 (2019).

https://doi.org/10.1038/s41550-019-0819-7 Download citation * Received: 06 January 2019 * Accepted: 15 May 2019 * Published: 08 July 2019 * Issue Date: October 2019 * DOI:

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