  A new approach to the old-standing problem of the anomaly of the scaling
exponents of nonlinear models of turbulence has been proposed and tested
through numerical simulations. This is achieved by constructing, for any given
nonlinear model, a linear model of passive advection of an auxiliary field
whose anomalous scaling exponents are the same as the scaling exponents of the
nonlinear problem. In this paper, we investigate this conjecture for the 2D
Navier-Stokes equations driven by an additive noise. In order to check this
conjecture, we analyze the coupled system Navier-Stokes/linear advection system
in the unknowns $(u,w)$. We introduce a parameter $\lambda$ which gives a
system $(u^\lambda,w^\lambda)$; this system is studied for any $\lambda$
proving its well posedness and the uniqueness of its invariant measure
$\mu^\lambda$.
  The key point is that for any $\lambda \neq 0$ the fields $u^\lambda$ and
$w^\lambda$ have the same scaling exponents, by assuming universality of the
scaling exponents to the force. In order to prove the same for the original
fields $u$ and $w$, we investigate the limit as $\lambda \to 0$, proving that
$\mu^\lambda$ weakly converges to $\mu^0$, where $\mu^0$ is the only invariant
measure for the joint system for $(u,w)$ when $\lambda=0$.
