  In this Chapter we examine the role of the ngVLA to further our understanding
of the different manifestations of convective or turbulence-driven stellar
activity on red giant and supergiant stars. The combination of high spatial
resolution and high sensitivity will enable the ngVLA to significantly improve
our understanding of the processes that dissipate energy in the extended
atmospheres of cool evolved stars, and drive ubiquitous stellar outflows. The
high spatial resolution will enable us to image the surfaces of nearby red
supergiants, and to measure the atmospheric extent of red giants.
Multi-frequency observations will permit thermal continuum tomography on the
largest angular diameter stars, providing key empirical data to test
theoretical models. The complementary frequencies and similar spatial
resolutions of the ngVLA and ALMA will be a powerful synergy.
