Lagrangian integral time (source code)

= Lagrangian integral time
{c}
{title2=$t_L=\int_0^\infty R_L(\tau)d\tau/R_L(0)$}

The Lagrangian integral time is the area under a normalized velocity <autocorrelation> along a <Lagrangian trajectory>. If this correlation is integrable, Taylor turbulent dispersion has asymptotic mean-square displacement $2R_L(0)t_Lt$. The integral time need not equal every short-time decorrelation scale, particularly when the autocorrelation oscillates.