Solar Physics & upper-Atmosphere Research Group Robert Erdélyi robertus 1 st Helas WS, Nice 25 –...

1st Helas WS, Nice 25 – 27 September 2006

University of Sheffield

Solar Physics & upper-Atmosphere Research Group

Robert Erdélyihttp://www.shef.ac.uk/~robertus





www.iaus247.org

LOC contact: Cesar Mendoza-Briceno (Venezuela)

SOC contact: Robertus Erdélyi (UK)




Leakage of photospheric motions Leakage of photospheric motions into the magnetic solar into the magnetic solar

atmosphere…atmosphere…R. Erdélyi

B. De Pontieu, C. Malins, B. Pintér, Y. Taroyan…

[email protected], Department of Applied Mathematics,

The University of Sheffield (UK)

http://www.shef.ac.uk/~robertus





IntroductionIntroduction

Reminder of a basic fact:

• Photosphere – chromosphere – TR (– corona are) magnetically coupled.

Manifestation of coupling has (at least) two exciting aspects:

• Influence of magnetic atmosphere, e.g. magnetic carpet on oscillations.

• Role of p modes in the dynamics of the solar atmosphere! (Less explored.)





Solar interior

• Global oscillations

• p, f, (g) modes

• One waveguide, many modes

Solar atmosphere

• More local oscillations

• Sunspot oscillations, prominence oscillations, coronal loop oscillations, plume oscillations

• One mode, many waveguides

Oscillations ubiquitous in Sun

Objects: atmospheric Objects: atmospheric oscillationsoscillations





Coupling scales and elementsCoupling scales and elements

¤ Magnetic fields

¤ Flow fields

Manifestations of presence in solar atmosphere:

Organised flows (meridional; differential rotation, etc.)

Random flows (granulation, convection, etc.)

Coherent global fields (e.g. canopy)

Random fields (magnetic carpet)





Simple-minded solar modelSimple-minded solar model corona

chro

mos

ph

eric

tr

ansi

tion

al

laye

r (L

)

photospherexzy g solar interior

B(z)

canopy (h)





Eigenmodes (L Eigenmodes (L 0, B 0, B 0) 0)





¤ Three-layer model

¤ Polytropic interior

¤ Magnetic transitional layer resonances damping

¤ Isothermal magnetic upper atmosphere

¤ Presence of Alfvén/slow continuum

¤Tirry et al. 1998, Pintér et al. 1999






¤ Three-layer model

¤ Polytropic interior

¤ Magnetic transitional layer resonances damping

¤ Isothermal magnetic upper atmosphere

¤ Presence of Alfvén/slow continuum

¤ Erdélyi and Pintér 2005

¤ Pintér et al. 2006

l = 100L = 2 Mm

Δν

(μ

Hz)

Bc (G)

p3

p8

p4

f

Bc (G)

p1 p2

l = 100L = 2 Mm

Im ν

(nH

z)Eigenmodes (L Eigenmodes (L 0, B 0, B 0) 0)





¤ Pintér, Erdélyi & Goossens 2006


Local magneto-seismology





Not steady waves but wave trains of finite duration. Oscillations usually last for 32±7 mins or 3 to 7 cycles (just like p modes): rarely continue for more than 40 min.

Wav

elet

ana

lysi

s us

ing

Mor

let w

avel

et (

k=6)

Lower atmospheric Lower atmospheric moss oscillationmoss oscillation

Oscillations usually suddenly start and stop.





pp-mode driven -mode driven spiculesspicules (and coronal (and coronal oscillations)oscillations)

Ver

tical

flu

x tu

be

Incl

ined

flu

x tu

be (

50°)

Chromospheric dynamics in inclined flux tubes are dominated by five minute periods because of significantly increased leakage of photospheric p modes into the atmosphere





P-mode driven spicules: 2-DP-mode driven spicules: 2-D





• Numerous examples of waves and oscillations by SOHO and TRACE in the solar atmosphere structures

• MHD theory seems to be a satisfactory description

• Atmospheric seismology provides us information about: magnetic field, transport coefficients, fine structures, etc.

• Coupling of photospheric motions (p modes, granules, etc.) to lower atmosphere (and above)

• Stratification has significant effect

• Lower atmosphere has back-reaction on global oscillations

SummarySummary





The end





Editors: Robertus Erdélyi ([email protected])

and John Leibacher ([email protected])

MHD Waves and Oscillations in Solar Magnetic Structures

Solar Physics “Topical Issue”

Deadline:12 January 2007

-Theory of MHD modes of magnetic structures- Magnetic helioseismology and waves in sunspots- MHD waves in the lower atmosphere- Prominence oscillations- Waves in the corona, MHD coronal seismology





LOC contact: Cesar Mendoza-Briceno (Venezuela)

SOC contact: Robertus Erdélyi (UK)

www.iaus247.org

Solar Physics & upper-Atmosphere Research Group Robert Erdélyi robertus 1 st Helas WS, Nice 25 –...

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