The role of spicules in heating the solar atmosphere

From observations of downflowing material at transition region temperature, together with reasonable assumptions about the fate of spicules after they disappear from view in the visual spectrum, it is shown that the rise and fall of spicular material can supply the thermal energy required by radiative losses from the transition region and upper chromosphere in the network. If sufficient heat is added to spicules, in conjunction with their acceleration, the spicule phenomenon may also play a major role in the production and maintenance of much of the solar corona. Thus, the processes whereby spicules are generated and heated may be of central importance to the energy balance of the outer solar atmosphere. This conclusion points to the need for developing an understanding of the acceleration and heating of spicules and to the need for observations of spicules after they have disappeared in the visual spectrum.