Da. Jones et Es. Titi, UPPER-BOUNDS ON THE NUMBER OF DETERMINING MODES, NODES, AND VOLUME ELEMENTS FOR THE NAVIER-STOKES EQUATIONS, Indiana University mathematics journal, 42(3), 1993, pp. 875-887
In this paper we present improved upper bounds on the number of determ
ining Fourier modes, determining nodes and volume elements for the Nav
ier-Stokes equations. The bounds presented here seem to agree with som
e of the heuristic physical estimates conjectured by Manley and Treve.