The work required per unit charge to move acharge from a reference point to a point at infinity (electric potential isdefined to be zero). The electric potential of a spacecraft is oftenreferred to as
the "spacecraft potential". The spacecraft potential is theelectric potential of the spacecraft relative to the potential of the nearbyplasma. The spacecraft potential is non-zero because the spacecraft chargesto the level that the emitted photoelectron flux going to infinity isbalanced by the plasma electron flux to the spacecraft.
The density of a unit of water after it is raised by an adiabatic process to the surface, i.e., determined from in-situ salinity and potential temperature (AGI, 1980). Density that would be reached by
a compressible fluid if it were adiabatically compressed or expanded to a standard pressure.
The temperature that a parcel would have if brought adiabatically and reversibly from its initial state to a standard reference pressure, typically 100 kPa.