We present an approximate inertial manifold based postprocess to enhance th
e accuracy of the spectral element method for evolutionary equations of dis
sipative type. The analysis shows that the postprocess improves the order o
f convergence. The postprocess consists on the resolution of a discrete ell
iptic problem only once when the time evolution has been completed. The ove
rcost is then negligible and the resulting postprocessed method is really a
n improvement over the standard spectral element discretization to which is
applied. (C) 2000 IMACS. Published by Elsevier Science B.V. All rights res
erved.