Climatology of Easterly Wave Disturbances of Northeast Brazil

A 21-year climatology of Easterly Wave Disturbances (EWDs) over Northeastem Brazil (NEB) region was constructed in order to obtain a better understanding of dynamic and synoptic processes life cycle of these systems, including genesis, growth I decay, trajectory and dissipation. The identification of EWDs was obtained subjectively through satellite images in infrared channel and fields of streamlines and relative vorticity at the levels 1000, 850, 700, 500 and 200 hPa from ERA-Interim reanalysis. During this period, 518 EWDs were identified, where 97% (3%) ofthese waves reach (do not reach) the NEB region, 64% (36%) were convective (non-convective) and 14% (86%) reached the Amazon region. The main systems that gave rise to DOLs were: Intertropical Convergence Zone (ITCZ), Upper- Tropospheric Cyclonic Vortices (UTCV), Cold Fronts (FF) and convective clusters from the west coast of Africa (AF). In addition, the interactions between systems AFIFF, AFIITCZ, AFIUTCV and ITCZIFF were associated with their formation. On average, we observed approximately 25 waves per year, with maximum (minimum) frequency between the months ofMarch to August (September to February) and, with pronounced interannual variability