Stereo　particle　imaging　velocimetry　measurements　and　reduced-order　modeling　are　combined　to　provide　a　full　picture　of　the　interaction　of　plasma　jets　with　a　turbulent　boundary　layer　(TBL).　Three　working　modes　of　the　plasma　actuator　are　investigated,　corresponding　to　a　unidirectional　jet　(mode　A),　a　steady　crashing　jet　(mode　B),　and　a　spanwise　oscillating　jet　(mode　C).　The　results　show　that　in　mode　C,　a　periodical　alteration　of　two　opposite　wall　jets　can　only　be　achieved　at　a　low　modulation　frequency　of　20　Hz.　As　the　frequency　increases　to　100　Hz,　the　two　unsteady　wall　jets　collide　in　the　middle,　producing　a　meandering　vertical　jet　column.　In　the　cross-flow　TBL,　mode　A　induces　a　single　streamwise　vortex,　which　grows　in　size　within　the　plasma　actuation　zone　and　decays　rapidly　in　strength　after　propagating　beyond.　As　a　comparison,　modes　B　and　C　produce　a　counter-rotating　vortex　pair　during　the　interaction.　The　skin-friction　drag　variations　within　the　plasma　actuation　zone　are　dominated　by　the　cross-stream　momentum　transportation　of　streamwise　vortices.　In　the　vortex　upwash　zone　where　a　strong　shear　is　present,　high　levels　of　turbulent　kinetic　energy　are　produced.　Physically,　the　spanwise　shaking　and　vertical　jumping　of　plasma　jet　heads　contribute　noticeably　to　turbulent　fluctuation.　Experimental　evidence　supports　the　simplification　of　a　streamwise　momentum　equation　into　a　nonlinear　transportation-diffusion　equation,　resulting　in　a　reduced-order　streamwise　vortex　transportation　model.　Detailed　comparison　with　the　experimental　data　shows　that　this　model　is　able　to　give　a　reasonable　prediction　of　the　cross-stream　flow　patterns　and　streamwise　velocity　variations　within　minutes.　©　2022　Author(s).