Connecting heavy precipitation events to outgoing long wave radiation variability scales: Case analysis in Brazil

Spatial fields of outgoing long wave radiation (OLR) spectrum variance of the 1979-2016 austral summer months in southern Brazil are analyzed on different timescales: synoptic, sub-monthly, and intra-seasonal. Variability fields differ both in intensity and location and highlight dominant convection...

ver descrição completa

Detalhes bibliográficos
Autores: Müller, Gabriela V., Fernandes, Valesca R.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2022
País:México
Recursos:UNIVERSIDAD NACIONAL AUTÓNOMA DE MÉXICO
Repositório:Atmósfera
Idioma:inglês
OAI Identifier:oai:ojs.pkp.sfu.ca:article/53028
Acesso em linha:https://www.revistascca.unam.mx/atm/index.php/atm/article/view/53028
Access Level:Acceso aberto
Palavra-chave:extreme event
scale interaction
outgoing longwave radiation
austral summer
Descrição
Resumo:Spatial fields of outgoing long wave radiation (OLR) spectrum variance of the 1979-2016 austral summer months in southern Brazil are analyzed on different timescales: synoptic, sub-monthly, and intra-seasonal. Variability fields differ both in intensity and location and highlight dominant convection cycles in the study area. The results show that the amplitude of sub-monthly variability is greater than that of the other scales in the southeastern region of Brazil, while the synoptic scale prevails in the southern region. The above-mentioned scales show greater amplitudes over the western Pacific Ocean where the Madden-Julian Oscillation plays an important role, along the South Pacific Convergence Zone, and over the storm track areas over the South Pacific Ocean. The influence of spectral OLR scale interaction is also analyzed, associated to the occurrence of two intense rainfall events over the southeastern Brazil in the austral summers of 2011 and 2014 when the South Atlantic Convergence Zone (SACZ) was active in both events. The results obtained suggest that spectral OLR scale interaction takes place in such way that it strengthens the SACZ, since the spatial pattern footprints of the two to eight-day timescale (synoptic), 10 to 30-day timescale (sub-monthly) and 30 to 60-day timescale (intra-seasonal) overlap in the study region.