Impacts of the Madden-Julian Oscillation on the intensity and spatial extent of heavy precipitation events in northern Northeast Brazil

Author(s)

Vasconcelos Junior, Francisco das Chagas ^[1] ; Jones, Charles ^{[2, 3]} ; Gandu, Adilson W. ^[4] ; Martins, Eduardo Savio P. R. ^[1]

Affiliation

^[1] Ceara Inst Meteorol & Water Resources FUNCEME, Fortaleza, Ceara - Brazil

^[2] Univ Calif Santa Barbara, Dept Geog, Santa Barbara, CA 93106 - USA

^[3] Univ Calif Santa Barbara, Earth Res Inst, Santa Barbara, CA 93106 - USA

^[4] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Ciencias Atmosfer, Sao Paulo - Brazil

• Document type: Journal article
• Source: INTERNATIONAL JOURNAL OF CLIMATOLOGY; v. 41, n. 6 FEB 2021.
• Web of Science Citations: 0

Abstract

This paper investigates the spatiotemporal variability of Contiguous Extreme Precipitation Events (CEPE) related to Madden-Julian Oscillation (MJO) activity during the pre-wet season and wet season in northern Northeast Brazil for 30 years (1979-2010). Inherent differences in rainy season regimes are associated with northern Northeast Brazil precipitation systems; these are isolated during pre-wet and wet season and analyse the intensity and the spatial area covered by the CEPE. A daily index of MJO activity and its life cycle were used to identify activity phases during heavy rainfall events. Composite analysis was performed for days with CEPE during the most frequent MJO phases in the pre-wet and wet seasons. The analysis shows the influence of the MJO on the occurrence of CEPE in northern Northeast Brazil. In the pre-wet season, the MJO phases 8-1-2 affect the occurrence of heavy rainfall events, modifying the atmospheric circulation and water vapour transport over northern South America. Indications of Rossby wave propagation over the South Pacific associated with MJO were found, suggesting tropic-extratropic teleconnection during occurrences of CEPE in the pre-wet season. In the wet season, CEPE events are more frequent during MJO phases 8-2-3. Conversely, no wave propagation over the South Pacific is observed in the wet season, changes in wind anomalies at high and low atmospheric levels only point to the influence of the MJO via tropical teleconnection. This study may help monitoring and forecasting of very heavy rainfall events in northern Northeast Brazil in pre-wet season and wet season. (AU)

• FAPESP's process: 13/09642-5 - Relations between high precipitation events in the northern Northeast Brazil and the role of the Madden-Julian oscillation
• Grantee: Francisco das Chagas Vasconcelos Júnior
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 11/09314-2 - Water vapor intraseasonal variability over northern Northeast Brazil and the southern hemisphere summer: present climate and future projections
• Grantee: Francisco das Chagas Vasconcelos Júnior
• Support Opportunities: Scholarships in Brazil - Doctorate