Reference / Input deck / solver / equations / sponge layer
sponge layer
Height-based wave-absorbing layer below the domain lid. Requires base_state
sigma maxrequired
float·required·> 0.0 1/s
Peak damping rate at the domain top
Used inatmosphere
start heightrequired
float·required·>= 0.0 m
Height where the damping ramp begins
Used inatmosphere
relax theta
bool·default True
Relax potential temperature toward the base state inside the sponge, as well as velocity. TRUE reproduces the existing behaviour: EnergyEqn.cu applies the sponge to theta whenever a sponge and a base state are present, which the deck's 'target velocity' wording does not convey. Set FALSE for a velocity-only sponge -- the upper boundary then stops being a heat sink, which is what isolates its effect on a stably-stratified case without also letting gravity waves reflect off the lid.
target velocity
list of float·not set by default·in m/s
Velocity the sponge damps toward; unset damps toward rest
Used inatmosphere