ANGEO Annales Geophysicae ANGEO Ann. Geophys. 1432-0576 Copernicus Publications Göttingen, Germany 10.5194/angeo-30-1727-2012 Remote estimation of reconnection parameters in the Earth's magnetotail: model and observations Alexandrova A. 1 6 Nakamura R. 1 Semenov V. S. 2 Kubyshkin I. V. 2 Apatenkov S. 2 Panov E. V. https://orcid.org/0000-0003-3609-235X 1 Korovinskiy D. https://orcid.org/0000-0002-7694-3422 1 Biernat H. 1 Baumjohann W. https://orcid.org/0000-0001-6271-0110 1 Glassmeier K.-H. 3 4 McFadden J. P. 5 Space Research Institute, Austrian Academy of Sciences, Graz, Austria St. Petersburg State University, St. Petersburg, Russia TU Braunschweig, Braunschweig, Germany Max-Planck Institute of Solar System Research, Katlenburg-Lindau,Germany Space Science Laboratory, University of California, Berkeley, CA, USA Invited contribution by A. Alexandrova, recipient of the EGU Outstanding Student Poster (OSP) Award 2011. 20 12 2012 30 12 1727 1741 Copyright: © 2012 A. Alexandrova et al. 2012 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://angeo.copernicus.org/articles/30/1727/2012/angeo-30-1727-2012.html The full text article is available as a PDF file from https://angeo.copernicus.org/articles/30/1727/2012/angeo-30-1727-2012.pdf

We develop a method to estimate the reconnected magnetic flux and the location of the reconnection site using properties of magnetic field and plasma velocity disturbances in the regions surrounding the reconnection plasma flow. Our analysis is based on a 3-D non-steady reconnection model with a finite-sized X-line length. In this framework, we obtain a system of equations capturing the relationships between the disturbances of the magnetic field and plasma flow from one side and the reconnection characteristics from another side. These equations allow us to determine the reconnection characteristics from one-point remote observations of the reconnection fast flow, propagated in the magnetotail current sheet. We apply the model to magnetic field and plasma observations at (−43, −11.2, −6.9) <I>R</I><sub>E</sub> GSM obtained by the THEMIS/ARTEMIS spacecraft, located in the tail lobe during a substorm event. We found that the reconnection region was located at ~ (−27, 3.5, 0) <I>R</I><sub>E</sub> GSM. The X-line appeared to be close to the local time of the substorm current wedge identified from ground-based observations. We estimated the total magnetic flux, which was reconnected in the event as ~5 MWb. That corresponds to a small fraction of the total amount of magnetic flux transferred during a substorm.

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