DJL equations
The Dubreil-Jacotin-Long (DJL) equation is derived from the steady Euler equations. The result is a single equation for the isopycnal displacement Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \eta} . Here are a few cases:
Boussinesq with constant background current
where . is the far upstream density profile, is a constant reference density ,and is the acceleration due to gravity.
Boussinesq with non-constant background current
Non-Boussinesq constant background current
where