Actas de congresos
Climatology of Easterly Wave Disturbances of Northeast Brazil
Fecha
2013Registro en:
Simpósio Internacional de Climatologia, 5, 2013, Florianópolis.
Autor
Gomes, Helber Barros
Ambrizzi, Tercio
Herdies, Dirceu Luís
Hodges, K. I.
Institución
Resumen
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.