Coefficient of thermal expansion
= Coefficient of thermal expansion
{title2=$\alpha_T=-\rho^{-1}(\partial\rho/\partial T)_p$}
The fractional <mass density> decrease per <temperature> increase at fixed <pressure>. In the <Boussinesq approximation>, a <temperature> excess $\theta$ gives <reduced gravity> $g'=g\alpha_T\theta$. It converts a <heat> budget into a buoyancy budget in <natural ventilation>.