EN
In this article some properties of Markovian mean ergodic operators are studied. As an application of the tools developed, and using the admissibility feature, a "reduction of order" technique for multiparameter admissible superadditive processes is obtained. This technique is later utilized to obtain a.e. convergence of averages $n^{-2} ∑_{i,j=0}^{n-1} f_{(i,j)}$ as well as their weighted version.