Isenthalpic Flow, Joule–Kelvin Coefficients and Mantle Convection

WALDBAUM 1 has suggested that, when mantle material convects according to the model of Turcotte and Oxburgh 2 , the temperature of an isolated rising mass will increase, “even in the idealized case where friction, viscosity and turbulence are ignored”. He argues from the premise that the steady adiabatic flow of a fluid is isenthalpic along streamlines: the Joule–Kelvin coefficient of the fluid can therefore be used to predict the temperature change during decompression.