Introduction
The importance of temperature T to physical problems of Earth's core is well understood. The adiabatic gradient dT/dz is also important because it induces the transfer of conductive power (the larger the adiabatic gradient, the more conductive power is transferred). When conduction is the dominant form of heat transfer, as it is in the transfer of heat from the core to the mantle, the relation between power Q (Watts) transferred and the adiabatic gradient is
where A (m2) is the area; k (
) is the thermal conductivity, a physical property of core material; and z (m) is depth. The ratio of Q to A is called energy flux, Q (
or 
).
In an adiabatic state, such as that found in Earth's outer core, the adiabatic gradient of the temperature profile is at constant entropy S, and dT/dz in Eq. 1 is replaced by 
. Equation 1 becomes
To evaluate Eq. 2 for the power transferred from the core to the mantle (at radius 1221 km, the core side of the core‐mantle boundary (CMB), or at pressure 
),...
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Anderson, O.L. (2007). CORE, ADIABATIC GRADIENT. In: Gubbins, D., Herrero-Bervera, E. (eds) Encyclopedia of Geomagnetism and Paleomagnetism. Springer, Dordrecht. https://doi.org/10.1007/978-1-4020-4423-6_43
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