Each engine has a vacuum thrust and an ASL thrust. Presumably, there is a linear relationship between thrust and outside pressure. Or, as pressure increases from 0 atm to 1 atm, thrust decreases from the vac thrust amount to the ASL thrust amount.
This seems intuitive to me, but it is only an assumption that my question is based on. Is this correct?
Now my question: what happens above 1 atm? Both Jool and Eve, as well as planets available from mods have atmospheres with a higher pressure than Kerbin. Does thrust continue to scale down to 0? Or is there actually some type of asymptotic/logarithmic relationship between thrust and pressure? Perhaps the ASL thrust is as low as an engine can get?