We extend the recently developed non-gaussian thermodynamic formalism [R.A.
Treumann, Physica Scripta, 59, 19 (1999)] of a (presumably strongly turbul
ent) non-Markovian medium to its most general form that allows for the form
ulation of a consistent thermodynamic theory. Ail thermodynamic functions,
including the definition of the temperature, am shown to be meaningful. The
thermodynamic potential from which all relevant physical information in eq
uilibrium can be extracted, is defined consistently. The most important fin
dings are the following two: (1) The temperature is defined exactly in the
same way as in classical statistical mechanics as the derivative of the ene
rgy with respect to the entropy at constant volume. (2) Observables am defi
ned in the same way as in Boltzmannian statistics as the linear averages of
the new equilibrium distribution function. This lets us conclude that the
new state is a real thermodynamic equilibrium in systems capable of strong
turbulence with the new distribution function replacing the Boltzmann distr
ibution in such systems. We discuss the ideal gas, find the equation of sta
te, and derive the specific heat and adiabatic exponent for such a gas. We
also derive the new Gibbsian distribution of states. Finally we discuss the
physical reasons for the development of such states and the observable pro
perties of the new distribution function.