Challenges in Understanding 3D Magnetic Reconnection in Observations and Simulations Session organizers: Peter Wyper (NASA Goddard Space Flight Center/Oak Ridge Associated Universities) Silvina Guidoni (NASA Goddard Space Flight Center/The Catholic University of America) Daughton et al., 2014 Wyper & Pontin, 2014 Kinetic scales MHD scales

Although we have a relatively complete understanding of reconnection in 2D, there are still many unanswered questions when considering 3D systems. Questions: Modeling: 1.What effects/physics is not captured by 2D modeling? 2.How do we define reconnection rate in 3D? Is this even a useful quantity? Observations: 1.What reconnection related phenomena (such as solar flares and jets, substorms, and FTEs) cannot be satisfactorily explained by 2D theories? 2.Can these observations help to further constrain theory and modeling efforts of 3D reconnection? Path Forward ● How can we combine current and future remote and in­situ observations, laboratory experiments, and simulations to better understand the basics of 3D reconnection? ● How can we make progress in extending previously gained 2D understanding into the fully 3D context?

When: Wednesday, July 8, 10:05AM 2D3D Priest, “Magnetohydrodynamics of the Sun”, 2014

Scene-setting speakers First half (10:05AM – 11:05AM) Michael Hesse (NASA Goddard Space Flight Center) Title: “Magnetic Reconnection in General, Three- Dimensional, Geometries” Discuss reconnection primarily from a theoretical point of view.

Scene-setting speakers Second half (11:30AM – 1:00PM) David McKenzie (Montana State University-Bozeman) Title: “How Can We Recognize Tearing Mode Signatures When They Occur?” Discuss reconnection primarily from an observational point of view.

We encourage the audience to asks questions and interrupt our speakers … Before the session, we can collect on one of our computers 1-2 slides from people that want to show their work, so they can be easily brought up. We cannot unfortunately guarantee that those that bring a slide to show will get to show or discus it. It will depend on the direction that both scene setting talks take during the session. But we hope to get as many people involved as we can!

Title First AuthorAffiliation Understanding the Effects of 3D Reconnection in a Breakout CME Spiro K Antiochos NASA/GSFC EUV burst, particle heating and whistler wave emission in fast magnetic reconnection induced by kink-driven Rayleigh-Taylor instability Paul Bellan Caltech Understanding Magnetic Reconnection Drivers: Magnetic Field Shear in Kinetic Models Carrie E Black NASA/GSFC Acceleration of particles in solar flare’s electromagnetic fields Dmitry Borovikov University of Michigan Electron Acceleration in 2D and 3D Magnetic Reconnection Joel Timothy Dahlin University of Maryland, College Park Analytic Method to Estimate Particle Acceleration in Flux Ropes Silvina E. Guidoni NASA GSFC/CUA Collision and reconnection of arched flux tubes Magnus Haw Caltech Magnetic Reconnection in General, Three-Dimensional, Geometries Michael Hesse NASA GSFC Simulations of Coronal-Hole Boundary Dynamics Near Helmet Streamers Aleida Katherine Higginson University of Michigan Plasmoid Instability Mediated Turbulent Reconnection, Simulations and Observations Yi-Min Huang Princeton University A Data Set of Flare-Ribbon Magnetic Fluxes: A Critical Tool for Understanding Solar Flares & Eruptions Maria D Kazachenko Space Sciences Laboratory, UC Berkeley Helicity Condensation During Reconnection of Twisted Flux Tubes: Implications for Coronal Heating Kalman Joshua Knizhnik NASA GSFC / JHU How gas-dynamic flare models powered by Petschek reconnection differ from those with ad hoc energy sources Dana Longcope Montana State University How Can We Recognize Tearing Mode Signatures When They Occur? David E McKenzie Montana State University The appearance, motion, and disappearance of 3D magnetic null points Nicholas A Murphy Smithsonian Astrophysical Observatory Concerning the effect of density and magnetic field asymmetries, and guide fields on reconnection poleward of the cusp Fathima Muzamil University of New Hampshire 3D Simulation of Periodic Release of Plasmoids from Helmet Streamers Dogacan Su Ozturk University of Michigan Supra-Arcade Downflows: Models versus Observations Sabrina Leah Savage NASA MSFC The Relation between CME Topologies and Observed Flare Features Antonia Stefanova Savcheva Harvard-Smithsonian Center for Astrophysics 3D Simulations of Flux Rope Formation and Tearing in Active Region Jets Peter Fraser Wyper NASA Goddard Space Flight Center Electron Heating in Reconnection Outflow with Riemann Simulations Qile Zhang University of Maryland,College Park Complex Flare Dynamics Initiated by a Filament-Filament Interaction Chunming Zhu New Mexico State University 22 Abstracts