Change in surface water ﹩{\rm{\Delta }}{M}_{{{\rm{H}}\,}_{2}\,{\rm{O}}}﹩ in TO of TOI-2257 b (super-Earth case) as a function of initial ﹩{M}_{{{\rm{H}}\,}_{2}\,{\rm{O}}}﹩ and ϵ_XUV. All the variables are logarithmic, including the ﹩{\rm{\Delta }}{M}_{{{\rm{H}}\,}_{2}\,{\rm{O}}}﹩ contour lines. The vertical segments correspond to scenarios in which photoevaporation of surface water has not exceeded the initial water inventory and surface water remains present. The horizontal segments indicate desiccation of surface water.