\def\uabs{\tilde{u}_{abs}}
\def\err{\epsilon}
\def\dsig{\dz \sigma}
\def\psk{{\ps}^\kappa}
\def\ucov{\tilde{u}}
\def\vcov{\tilde{v}}
\def\ucont{\tilde{\ucov}}
\def\vcont{\tilde{\vcov}}
\def\cu{c_u}
\def\cv{c_v}
\def\h{\theta}
\def\pext{\tilde{p}_s}
\def\fext{f}
\def\K{\frac{1}{2}
\left( \av{\ucov \ucont}{X} + \av{\vcov \vcont}{Y} \right)}
\def\Z{\frac{\dx \vcov - \dy \ucov + \fext}{\av{\pext}{X,Y}}}
\def\Zm{\frac{- \dy \ucov + \fext}{\av{\pext}{Y}}}

\newcommand{\glob}[1]{ \left< #1 \right> }
