V. M. Mishin and V. V. Mishin, Institute of Solar-Terrestrial Physics RAS, Irkutsk Substorms on the Earth and Flares on the Sun: the examples of analogies and differences. Presenting author: Mishin V.V. Abstract. In the conception of a substorm and its expansion phase, there are two well-known scenarios: Inside - Out (IO) and Outside- In (OI). In the both ones there are 5 major processes: 1) magnetic reconnection in dayside magnetopause (MRD), 2) magnetic reconnection of closed tail (MR1), 3) reconnection of open lobe (MR2), 4) formation of the cross-tail current disruption (CD) with 5) substorm current wedge formation (SCW). We suppose that IO-substorms and OI-substorms or their synthesis are all observed. It is supported by the facts that the solar flares and CMEs both are produced by basic processes which are similar to above-mentioned magnetospheric ones (MRD, MR1, MR2, and CD/ SCW), and flares differ from CMEs like IO differs from OI. My task is to illustrate some selected points of the substorm-flare analogy, and to show on interesting example that the solar flare scenario can be used to update the substorm scenario and to describe new system of FACs flowing into the ionosphere from the plasmoid of the distant geomagnetic tail during the substorm expansion phase.

Fig.1a. Meridional section of open geomagnetosphere for southward IMF (on the left), its tail (center) and the magnetic arcade of the flare region (FR). Stretched field lines of nonpotential magnetic field are shown. Red dotted line: B x=0. N 1 and N 2 – neutral points. Fig. 1. b. On the right: magnetic arcade of the flare region (thick solid lines), and two ring currents around two chromospheric foots of this arcade (dashed lines with arrows) (transition region and plasmoid not shown). The magnetic field of the current,  B =  B x, is directed so that it increases the height of the top loop like in Earth’s magnetotail. On the left: the system of currents J ~ V  B of the generator (the boundary is shown by a dashed line), and the closing currents in the chromosphere Magnetic field configuration

Magnetic arcade on the Sun, lower part Fig. 2a. The lower part of the magnetic arcade of the flare region (FR), and the contour (ellipse), which contains the bases of magnetic loops, are shown. Also the vertical current sheet near the neutral plane of the FR is shown (red lines). This current sheet divides FR onto two halves with magnetic fields of opposite directions. In the vertical sheet there is electric current of the load ( jE)>0. Fig. 2b. The solar flare current wedge model (green lines). Scheme shows how the ribbon in the chromospheric base of the flare region moves from the neutral line, (along the Z-axis) when disruption in the vertical current sheet moves upward (along the X-axis) from lower position I to higher positions II and III. The vertical current sheet is shown by red solid lines, its disruption- red dotted lines.

Fig.3. Maps of FACs density in the ionosphere (geomagnetic latitude  > 50 o ). Thick violet lines are the boundaries of three Iijima-Potemra Regions: R1, R2 and R0. Blue and black isolines of the FAC pattern indicate downward /upward FAC, respectively. Two meridians around the midnight meridian limit SCW area. The special interesting new detail is the westward traveling edge (WTE) of the downward FAC. It (WTE) can be seen near border of nighttime areas R1 and R0 on ~21-hour meridian of MLT. WTE is shown by three arrowed black lines. This WTE is observed during the substorm expansion phase (EP). We accept that WTE is foot of FAC mapping along field lines from the plasmoid of distant tail. The nature of this FAC can be understood using the substorm-flare analogy and the flare scenario of Shibata, 1997 (Fig. 5)

Some key parameters of a substorm Fig.4a. Here are shown the IMF components (Wind data), AE - index and five parameters calculated with using the magnetogram inversion technique, MIT [Mishin, 1990, 2011]: the variable part of open tail lobes magnetic flux (  1 ), Poynting flux from solar wind (  ), total power of the substorm (Q), intensity (total current) in SCW (J CD ), and energy: stored in tail (W*), and consumed in the magnetosphere/ionosphere (W). One can see that two substorm onsets are observed sequentially. The first is EP1, prompt growth of the J CD, of SCW intensity. This fact means also that the cross tail current disruption (CD) is amplified simultaneously. The second is EP2 - prompt drop of  1 that means onset of the tail lobes magnetic flux reconnection. Let us compare it with the solar flare parameters

Fig. 4b. Changes of parameters of statistical flare. Statistical flare was obtained by data averaging of eleven flares. Moment T = 0 - the beginning of the main (unloaded) active phase, marked by two asterisks **. The onset of the first active phase is marked by a single asterisk *. From top to bottom: S 2 - area of H  -ribbons,  nonpotential ascending magnetic flux; Q - full flare power;  ‘- Poynting flux into the flare region. Fig. 4c. H  - filtrogram of the flare on May 14, Here are shown two basic ribbons of the flare and the orthogonal pair of SEFR ribbons (structures on the ends of flare ribbons). On the left - variations of the basic ribbons parameters. Behavior of  is similar to one shown in Fig.4a in the case of magnetosphere. X-Ray intensity and full flare power decay more slowly.

Fig. 5. 3D model of the solar flare of LDE type [Shibata, 1997], supplemented. Here are shown the field lines and plasmoid. A and A are two well-known basic flare ribbons in the solar chromosphere. These ribbons are analogs of two auroral ovals. B and B is the orthogonal pair of the ribbons that is known as the structures of the ends of flare ribbons, SEFR (e.g., Sidorov, 2011 and references therein]. This pair B, B in Shibata’s model is connected with the plasmoid by the FAC ( magnetic field is also shown). We accept that one of these two ribbons is Earth analog of WTE in one hemisphere, and other ribbon is analog of WTE in other Earth’s hemisphere. This is new important example to show how solar data can be used to decode the observations in geomagnetosphere by using solar observations. There are also examples to show how to use magnetospheric data to understand some unexplained solar data.

1. Central processes - a magnetic reconnection (MR) - Fig. 1а (scheme) 1. Central processes - the same - Fig. 1с (scheme) 2. Two auroral ovals – Fig, 1a, b 2. Two ribbons in H  - Fig. 1с 3. Substorm is initiated by MR at dayside magnetopause - Fig. 1a, b 3. Flare is initiated by MR in convection zone 4. During 1-st phase (growth phase) tail lobes - 2 sheaves of open field lines - Fig. 1 а, b, Fig. 8 а (2D model, Birn and Hesse, 2009) are formed 4. During preliminary phase of flare the cloud of plasma with flux  of "open" field lines and vertex of an arcade inside a flux emerges - Figs 1 с, a, Fig. 7 (Shibata, 1996), Fig. 8b (Birn and Hesse, 2009) 5. During growth phase - increase of tail lobes magnetic flux  and Poynting flux into the geomagnetosphere - Fig. 2 (data MIT) 5. During preliminary phase of flare –- increase of FR tail lobes magnetic flux  and Poynting flux into the FR magnetosphere - Fig. 3 (data H , MIT) 6. During growth phase in a tail energy W ensuring observable energy of substorm W* is loaded - Fig. 2 (MIT ) 6. During preliminary phase in FR tail energy W ensuring observable energy of flare W* is loaded – Fig.3 (H , MIT) 7. The magnetic field of a perturbed magnetosphere is formed- Fig. 8a 7. The magnetic field of a perturbed FR magnetosphere is formed- Fig. 8b. 8. Formating of main, dawn-dusk current of the plasma sheet with maxima of density in the near tail - Fig. 8a (2D model) 8. Formating of vertical layer of Y- current in plasma sheet of arcade Fig. 8b (2D) and Fig. 13 (3D scheme). 9. The turning (hinge) area of magnetic field is formed – Fig. 8a. 9. The turning (hinge) area of magnetic field is formed - Fig. 8b.