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Solar corona:open questions mission will help us to solve them Max-Planck-Institut für Sonnensystemforschung Max-Planck-Institut für Sonnensystemforschung J. Büchner The solar corona - open questions ESAC, June 10, 2011 ) w as o l S,be o Axord

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MPS moves 2014 to Göttingen 2014: New 003 Götti with director/ since 2 MPS building in (since 1973 MPAe J. Büchner The solar corona - open questions ESAC, June 10, 2011 January in Göttingen MPS 2014: J. Büchner The solar corona - open questions ESAC, June 10, 2011 Starting in 2014: MPS Göttingen J. Büchner The solar corona - open questions ESAC, June 10, 2011

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> coronal mass west limb. 38:30 h of NASA- SDO (AIA) s/c observations (from -> M-2 (medium- sized) flare -> S1-class (minor) radiation storm - ~ 7:00 UT from ARs (sunspot complex) 1226 ejection (CME) June 7 launched on June 5 20:30 UT – June 7 11:00 UT)

Solar storm ,Tuesday 7.7.2011: J. Büchner The solar corona - open questions ESAC, June 10, 2011

t and ons a Å ti observed

wavelengths , 193 serva Å Å b flux

o fbf ti t 211 Top graph - the X- ray flux observed at Main movie: an SDO zoom-in composite o 171 (21.1, 19.3, 17.1 nm) Between June 7 6:10 UT and June 7 7:13 UT (Blast: 6:20 – 6:41) rays the geostationary orbit by GOES-15 - X h

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SDO thre composite J. Büchner The solar corona - open questions ESAC, June 10, 2011 behind

Stereo

Stereo coronographs ahead

Stereo J. Büchner The solar corona - open questions ESAC, June 10, 2011 known

processes not is it

But: yet, what the physical behind are! •

Schematics J. Büchner The solar corona - open questions ESAC, June 10, 2011

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radiative via and coronal helioseismology releases local complex by conduction energy often heat , , field resolution -

indirectly ) B fields

Challenging conditions B pixel ( , scale

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observed Main energy input from below the atmosphere – could Considerably inhomogeneous plasma, structured by be The (B) builts current sheets, whose sizespatial is below the Large gravity often explosively but also quasi-stationarily • • • • J. Büchner The solar corona - open questions ESAC, June 10, 2011 Reconnection-> xxx ???

J. Büchner The solar corona - open questions ESAC, June 10, 2011 directed

oppositely

flux is oppositely directed • Eruptions, when newly emerging -> • , Tripathi

2005]

Observations before eruptions [Bothmer & Tripathi • J. Büchner The solar corona - open questions ESAC, June 10, 2011 Example: eruption of AR 8210

GIF-Bild AR 8210 195 Å (EUV) observation SOHO/EIT

12. 09. 2000

After long accumulation of magnetic shear:

Flare eruption at 11:48 UT

J. Büchner The solar corona - open questions ESAC, June 10, 2011 Magnetic flux emergence

Magnetic Field Movie.gif

SoHO/MDI B-field 10.- 13.09 .2000 , Flare burst on 12.9.00 at 11:48 UT

Site of the emergence of new magnetic flux

J. Büchner The solar corona - open questions ESAC, June 10, 2011 Two-dimensionalcartoons J. Büchner The solar corona - open questions ESAC, June 10, 2011 index the ( „0“ indicates chromosph. neutrals coupled to the plasma)

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What controls the B-field? ~10 ~ m In RMHD induction eq. Typical for the solar corona Reynolds numbers R cannot simply by dissipated (in contrast to the chromospheric Jpar currents!) J. Büchner The solar corona - open questions ESAC, June 10, 2011 ~1 : m eets h become es to biliti a t has e current s ns h i t biliti m R ng t cro- i i nn om hi i t yt ue b

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lit l n I for [Büchner & Elkina 2006/2007] –fo – for lower beta plasmaBut: as 2D: LH turbulence –> threshold: ve by plasma turbulence as obtained by Vlasov code simulations In the (lower) chromosphere: by binary particle collision rate [Spitzer-Härm–Braginski Theory 1958-63] The resistivity, parametrizedThe resistivity, via an effective „collision frequency“, is dominated J. Büchner The solar corona - open questions ESAC, June 10, 2011 eff a t e ( y it v iti it ous res l anoma d en d epen ddd d y it oc lit l

Resistivity models ve r e i carr t urren Ct C =10^9 times the Spitzer resistivity ) Current density dependend resistivity Resistivity models used: J. Büchner The solar corona - open questions ESAC, June 10, 2011

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F [Priest & Pontin 2009]: an; F Spine / Fan / Shear Is decided by flows! flow reconnection -> Classification e g by maxima - B ne, i p the {S i F F } to Eigenvalues of the Jacobian B around the null: {+2; -1.7; -0.3} the null: B around This coronal 3D results null fromquadrupolar a photospheric B-field via its fan and spineconnected field lines it is

Coronal magnetic Null J. Büchner The solar corona - open questions ESAC, June 10, 2011 If the theplasma at the footpoints of the fan field lines is moved clockwise -> strong central shear -> Formation of a current channel below the Null [Santos,Büchner,Otto,11] (from t he ti tl e page of Astronomy& Astrophys., Januaryy) 2011)

J. Büchner The solar corona - open questions ESAC, June 10, 2011 c i the both r t r at ec ine field lti l p e j a case where the Result fo plasma footpoints of the s lines are moved clockwise: Et j maximum below the Null fields are

Corresponding Epar distribution J. Büchner The solar corona - open questions Beijing, CAS, 26.5.2011 f

yet

not Plasma

, : Plasma extrapolated input scales fields - B On average: height- add Energy stratified equilibrium motion in the photosphere - - from observated LOS - - Important: Rescaling o current densities to the plasma resolvable by MHD erature p tem ] ht g hei [

y y[ g ] p

Initial stratified equilibrium Plasma densit and pressure in the solar gravitation J. Büchner The solar corona - open questions ESAC, June 10, 2011 , y . energy t causes photospheric complex owes ones - and, finall reconnection. The solar magnetic is the plasma motion away from the lt l This currents including non-force-free ones - and, finall state. It evolves due to

+ initial + magnetic field => J. Büchner The solar corona - open questions Beijing, CAS, 26.5.2011 rated g -here: field-line inte r a p E g 3D reconnection 3D is characterized by stron

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3D reconnection through QSLs B 3D reconnection due to - og l opo Finite tlil t plasma motion through a QSL (quasi-separatrix-layer = J. Büchner The solar corona - open questions ESAC, June 10, 2011 `` 6 . otential 41 6 p - . olated p pp between

latitude Mm

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Magnetic field at 1:36 UTC for an area of about 180 Mm x 180 Mm between longitude and and 211,8`` 536.7`` and 790.1`` latitude June 26, 1996 located on inside a coronal hole around at 55 fields. (Polar coronal hole) Magnetic field at 1:36 UTC for an area of about 180 Mm Shown are also projections of the extra

Coronal observations hole J. Büchner The solar corona - open questions ESAC, June 10, 2011 of o sts i low s – open n co s sts netic flux d g l e ed The magnetic fi funnels ma along the boundaries of the coronal hole and rising loops inside and outside the outside the hole

3D magnetic field structure J. Büchner The solar corona - open questions ESAC, June 10, 2011

plasma

and km/s accelerate

upward blue: upward red: downward The isosurfaces Vz=10 km/s • • demonstrate: 3D reconnection electric fields accelerate plasma downward both

Epar acceleration -> Plasma J. Büchner The solar corona - open questions ESAC, June 10, 2011

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E dA dt ( () ral ove dE d N g • release is the energy ouburst event within • (The total energy [Aschwanden probability of an • • inte and Parnell 2008]

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2011 October

definition phase of 1. Solar Orbiter, 2. Euclid, 3. Plato; ESA decision2. Euclid, o 2 M-class launches (470 MEURO) 2017 & 18 in Launch: January 2017, but ongoing:

Solar Orbiter - The Mission J. Büchner The solar corona - open questions ESAC, June 10, 2011 s t u measuremen or. it t t n-s i mission!

ar equa l ever t class mission! - e so M

th oses Solar Orbiter s: l l o t

ttt th l t Type

c goa orm c flti f ifi produce images of the Sun at high resolution produce images of the Sun at high per The Sun in visible light, extreme ultra violet, X-rays Elliptical orbit around the Sun, perihelion 0.28 AU increasing up to more than 30°inclination with respec pec – – – – – Main question: How does the Solar System Main question: work? Target: Sifil S nominal Type M Lifetime: 9-10 years, i.e. more than the 6 years for a Orbit: • • • • • J. Büchner The solar corona - open questions ESAC, June 10, 2011 )

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Germany:

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Liege , extreme

Remote sensing instruments sensing Remote - at the moment! is not funded by NASA the

Rochus . Magnetograph-Polarimeter P Rochus PHI: EUI( STIX:X-ray Potsdam, Germany) AIP Spectrometer(A. Benz,Switzerland+UniKiel/ CoronalMETIS: and spectrograph imager Antonucci, Italy (E. MPS Germany) + SPICE: the extreme ultraviolet imaging spectrograph (Don Antonio) J. Büchner The solar corona - open questions ESAC, June 10, 2011 (FSI)

(HRI)

imager

imagers

sun imager (FSI) - full

EUI –EUI Imager the EUV α resolution band

dual high

Lyman- 174 and 304 Å EUV EUV (174 Å) EUV (174 • • • Two high resolution imagers (HRI) One dual band full The EUI instrument suite: The EUI instrument • • J. Büchner The solar corona - open questions ESAC, June 10, 2011 pectroscopy S Spectrometer maging and I and

METIS elescope for T Coronograph

a - lement E ulti M - the J. Büchner The solar corona - open questions ESAC, June 10, 2011 PHI elioseismic olarimetric and mager The P H I J. Büchner The solar corona - open questions ESAC, June 10, 2011 In situ instrument packages instrument situ In J. Büchner The solar corona - open questions ESAC, June 10, 2011 nstruments i tu i n-s I : s instrument sensing - Instruments‘ accomodation locations and fields of view Remote J. Büchner The solar corona - open questions ESAC, June 10, 2011 Summary - Mission overview J. Büchner The solar corona - open questions ESAC, June 10, 2011