The TAI second is defined relative to a particular gravitational potential. Adapting to another known one is just a unit change. (if you don't know then nothing

The TAI second is defined relative to a particular gravitational potential. Adapting to another known one is just a unit change. (if you don't know then nothing can help you). The difference between potential already need to get handled on earth. Esp. since the NIST labs in boulder are at about 5400 feet.