I'm reading some literature on mass loss in the RGB/AGB branches and so far I'm getting a lot of information regarding mass loss via dusty-winds/pulsations but almost no explanation of mass loss by 'chromosphere activity'. I asked my mentor about it and he couldn't come up with anything so I'm turning to whomever might be able to throw a few references or explanations my way.
I guess what is meant is mass loss powered by non-radiative heating occurring above the photosphere. i.e The outer atmosphere is heated by magnetic Alfven waves and causes a wind to stream away from the star. The same magnetic field is responsible for heating a chromosphere - a hotter layer above the photosphere.
Here is a paper by Schroder and Cuntz (2005), though not really at an introductory level.