Left panel: the grid of model atmospheres used to generate Hα emission. The atmosphere grid is based on model photospheres with five different ﹩{{T}_{{\rm eff}}}﹩ (3400, 2900, 2400, 1900, and 1400 K from top to bottom, roughly corresponding to M0, M4, M8, L3, and L7 dwarfs, respectively) with thirteen different chromospheric temperature structures attached at log(﹩{{m}_{{\rm col}}}﹩) = 0.5. Each chromosphere break is shown in a different color; the hottest chromospheres are shown in red and the coolest chromospheres are in purple. Right panel: the log of Hα surface flux as a function of photosphere ﹩{{T}_{{\rm eff}}}﹩, with results from each chromosphere break represented by the same color as in the left panel. Hα lines that were in absorption are not shown.