Buoyancy gradient
= Buoyancy gradient
{title2=$\nabla b$}
The spatial <gradient> of <buoyancy> determines the buoyancy anomaly produced by a small parcel <displacement>: $b'=-\boldsymbol\xi\cdot\nabla\bar b$. Its vertical component is the squared <buoyancy frequency> in a stably stratified <Boussinesq approximation>. A horizontal component enters <thermal wind> and the propagation of a <Boundary Rossby wave>.