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Two of the central problems in our understanding of the solar chromosphereare how the upper chromosphere is heated and what drives spicules. Estimates ofthe required chromospheric heating, based on radiative and conductive lossessuggest a rate of ${\sim} 0.1 \mathrm{\:erg\:cm^{-3}\:s^{-1}}$ in the lowerchromosphere dropping to ${\sim} 10^{-3} \mathrm{\:erg\:cm^{-3}\:s^{-1}}$ inthe upper chromosphere (\citet{Avrett1981}). The chromosphere is also permeatedby spicules, higher density plasma from the lower atmosphere propelled upwardsat speeds of ${\sim} 10-20 \mathrm{\:km\:s^{-1}}$, for so called Type-Ispicules (\citet{Pereira2012,Zhang2012}), reaching heights of ${\sim} 3000-5000\mathrm{\:km}$ above the photosphere. A clearer understanding of chromosphericdynamics, its heating and the formation of spicules, is thus of centralimportance to solar atmospheric science. For over thirty years it has beenproposed that photospheric driving of MHD waves may be responsible for bothheating and spicule formation. This paper presents results from ahigh-resolution MHD treatment of photospheric driven Alfv\'en and kink wavespropagating upwards into an expanding flux tube embedded in a modelchromospheric atmosphere. We show that the ponderomotive coupling from Alfv\'enand kink waves into slow modes generates shocks which both heat the upperchromosphere and drive spicules. These simulations show that wave driving ofthe solar chromosphere can give a local heating rate which matches observationsand drive spicules consistent with Type-I observations all within a singlecoherent model.

Simulations of Alfven wave driving of the solar chromosphere - efficient heating and spicule launching