1. Sakai, J. I., Nishi, K., and Sokolov, I. V. ApJ, 2002, 576, 1018
Heating of coronal loop footpoints by slingshot magnetic reconnection during two loop interactions driven by a moving solitary magnetic kink
Sakai, J. I., Nishi, K., and Sokolov, I. V.
ApJ, 2002, 576, 1018

2. Background-theories Possible coronal heating mechanism:
MHD waves propagate and dissipate (e.g., Steiner et al. 1994, Ofman, et al. 1998, Sakurai, 1985 )
Current sheets heating at the topologic interface (e.g., Parker 1972, Glencross 1975, Rosner et al. 1978, Sturrock and Uchida 1981, Demoulin and Priest 1997)---- but it is hard to detect the existence of current in the corona at present

3. Background-observations
TRACE EUV observations (Lenz et al. 1999; Aschwanden et al. 2000, 2001)  near-isothermal loop T structure, multithreads, heated near the footpoints for some EUV loops
TRACE EUV observations (Schrijver 1999, Qiu et al. 1999)
 existence of up- and downflows in active region loops

4. Sakai’s previous main results
Collision of magnetic flux tubes  shock formation and upflows (2000a)
Collision between the shock waves and the loops  surface Alfven waves (2000b)
Nonlinear MHD wave propagation  upward torsional and compressional waves (2000c, 2001a)
Surface Alfven waves and upward plasma  magnetic reconnection  Chromospheric loop heating model (2001b)

5. The present work
To investigate reconnection between a vertical loop and a low-lying loop driven by the ‘moving solitary magnetic kink’ (MoSMak)  Coronal loop heating ?

6. Formation of a MoSMaK
Head-on collision process of two dense plasma blobs in a twisted magnetic flux tube (the plasma blobs can be driven by the flux tube collisions near the photosphere)
Iso-surface of |B|=0.32
A=2a/VA, a=20

7. Velocity structure of the MoSMaK
Bx-By
Vx-Vy
(1)
(2)
(3)
Iso-surface of |v|=0.2

8. Time evolution of the head-on collision process of two MoSMaKs
Iso-surface of |B|=0.19
Horizontal loop
Strong expanding toroidal flux

9. Time evolution of the iso-surface of |B|=0.19
Vertical loop
Sling-shot reconnection appears

10. Time evolution of the iso-surface of |B|=0.31 with different view

11. Time evolution of By-Bz (x=100)
Time evolution of Bx-Bz (y=100)
Time evolution of By-Bz (x=100)

12. Time evolution of the iso-surface of |V|=0.15
Time evolution of Vy-Vz (x=100)
Time evolution of the iso-surface of |V|=0.15

13. Velocity distribution on Z=200 at t=28

14. Vertical loop heating

15. conclusion
A new local heating model of loop footpoints in the chromosphere is proposed
Non-uniform heating by slingshot reconnection, driven by the MoSMaKs
The loop interaction results in the formation of both helical up- and downflows