Jet and Vortex Actuator (JaVA) is a zero-net-mass flux evice for active flow control of boundary layers and transition. VA produces various jets which can be used to delay flow paration or to "steer" the boundary layer velocity profile. In Lis study, numerical simulations of JaVA-boundary layer lteractions are analyzed using Proper Orthogonal ecomposition (POD). JaVA-induced flow regimes are Dverned by the plate width (b), the amplitude (a) and the Derating frequency (f). In this study the frequency is changed etween 2/3 Hz and 8/3 Hz keeping the plate width and the mplitude constant. A commercial finite-volume-based nsteady, laminar, incompressible Navier-Stokes solver has een used to study the flow fields generated by JaVA. Then, OD is applied to time dependent snapshots of velocity fields at ach operating frequency. The POD modes revealed the ehavior of the flat plate boundary layer under the effect of Dtive flow control. Traveling modes can be captured in the uccessive modes for high frequencies.