Magnetic Untwisting in Solar Jets that Go into the Outer Corona in Polar Coronal Holes

Abstract

We present results from 14 exceptionally highreaching large solar jets observed in the polar coronal holes. EUV movies from SDO/AIA show that each jet is similar to many other similarsize and smaller jets that erupt in coronal holes, but each is exceptional in that it goes higher than most other jets, so high that it is observed in the outer corona beyond 2.2 R(sub Sun) in images from the SOHO/LASCO/C2 coronagraph. For these highreaching jets, we find: (1) the front of the jet transits the corona below 2.2 R(sub Sun) at a speed typically several times the sound speed; (2) each jet displays an exceptionally large amount of spin as it erupts; (3) in the outer corona, most jets display oscillatory swaying having an amplitude of a few degrees and a period of order 1 hour. We conclude that these jets are magnetically driven, propose that the driver is a magneticuntwisting wave that is grossly a largeamplitude (i.e., nonlinear) torsional Alfven wave that is put into the reconnected open magnetic field in the jet by interchange reconnection as the jet erupts, and estimate from the measured spinning and swaying that the magneticuntwisting wave loses most of its energy in the inner corona below 2.2 R(sub Sun). From these results for these big jets, we reason that the torsional magnetic waves observed in TypeII spicules should dissipate in the corona in the same way and could thereby power much of the coronal heating in coronal holes