%0 Journal Article
%4 sid.inpe.br/plutao/2019/06.10.14.33.31
%2 sid.inpe.br/plutao/2019/06.10.14.33.32
%@doi 10.1007/s00382-019-04667-7
%@issn 0930-7575
%F lattes: 3752951275341381 6 GomesAPHSHSG:2019:ClEaWa
%T Climatology of easterly wave disturbances over the tropical South Atlantic
%D 2019
%9 journal article
%A Gomes, Helber B.,
%A Ambrizzi, Tércio,
%A Pontes da Silva, Bruce F.,
%A Hodges, Kevin,
%A Silva Dias, Pedro L.,
%A Herdies, Dirceu Luis,
%A Silva, Maria Cristina L.,
%A Gomes, Heliofábio B.,
%@affiliation Universidade Federal do Alagoas (UFAL)
%@affiliation Universidade de São Paulo (USP)
%@affiliation Instituto de Pesquisa Capixaba
%@affiliation University of Reading
%@affiliation Universidade de São Paulo (USP)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Universidade Federal do Alagoas (UFAL)
%@affiliation Universidade Federal do Alagoas (UFAL)
%@electronicmailaddress helber.gomes@icat.ufal.br
%@electronicmailaddress
%@electronicmailaddress
%@electronicmailaddress
%@electronicmailaddress
%@electronicmailaddress dirceu.herdies@inpe.br
%B Climate Dynamics
%V 51
%P 1-19
%K Easterly waves disturbances · Tropical South Atlantic · Northeast Brazil and climatology.
%X A 21-year climatology of Easterly Waves Disturbances (EWDs) over the tropical South Atlantic (TSA) has been examined using data from the European Centers for Medium-Range Weather Forecasting interim reanalysis (ERAI) and satellite data. This includes the frequency distribution of EWDs and their interannual variability. The large-scale environment associated with EWDs has been investigated for the coastal region of Northeast Brazil (NEB) for the rainy (AprilAugust) season using a composite analysis. EWDs were first identified in ERAI, resulting in 518 observed cases. These were found to show notable interannual variability with around 1640 episodes each year and with an average lifetime of 46 days. Of the identified EWDs, 97% reached the coast of NEB, of which 64% were convective in nature and 14% moved across the NEB region and reached the Amazon. The annual occurrence of EWDs seems to be lower (higher) during El Niño (La Niña). The monthly occurrence of EWDs shows higher activity in the rainy season. EWDs originate in association with four types of system: cold fronts, convective clusters from the west coast of Africa, Intertropical Convergence Zone and Tropical Upper Tropospheric Cyclonic Vortices. The composite analysis indicates strong relative vorticity and divergence anomalies at low levels, as well as in the vertical profiles of relative humidity and vertical velocity (omega). The precipitation composites show that the EWDs propagate between the TSA and NEB and contribute at least 60% of the total rainfall over the east coast of NEB throughout the rainy season.
%@language en
%3 Gomes2019_Article_ClimatologyOfEasterlyWaveDistu.pdf