Dissertation defense
Student: Paulo de Rosa Lombardi
Program: Meteorologia
Title: “Impacto da Oscilação de Madden-Julian na velocidade do vento na região Nordeste do Brasil”
Advisor: Prof. Dr. Tércio Ambrizzi
Judging Committee:
- Prof. Dr. Tercio Ambrizzi - IAG/USP
- Prof. Dr. Everaldo Barreiros de Souza - UFPA - por videoconferência
- Prof. Dr. Cristiano Prestrelo de Oliveira - UFRN - por videoconferência
Abstract
The northeastern Brazil has a high windpower potential and the wind’s regularity can be affected by meteorological systems commonly influenced by Madden-Julian Oscilation (MJO). With the time series of RMM1 and RMM2 indexes for the MJO’s life cycle and a composities analysis for wind speed anomalies at 100 m, the MJO’s impact on the wind speed in Northeastern Brazil was evaluated in each phase and month of the year. Phases 1, 2 and 8 are the most unfavorable to wind. On the other hand, phases 4, 5 and 6 are the most favorable. Phases 3 and 7 represent a more transitional behavior, with phase 3 being closer to phases 1, 2 and 8, especially in the months of February to April, while phase 7 is closer to phases 4, 5 and 6, except between winter and spring. The same composities analysis was applied to sea level pressure and geopotential height, current function and velocity potential at 250 and 500 hPa. The weaker winds in phases 1, 2 and 8 can be understood by the upper troposphere divergence anomaly in South America and the Intertropical Convergence Zone (ITCZ) region, the favorable atmospheric circulation to lower latitudes displacement of transient systems, the weakening and/or distancing of South Atlantic Subtropical Anticyclone (SASA) and, less frequently, a possible intensification and/or eastward displacement of the Bolivian High. In the case of phases 4, 5 and 6, the stronger winds can be explained by the upper troposphere convergence anomaly over South America and the ITCZ region, the strengthening of SASA or the emergence of an anomalous high close to Brazilian coast, the unfavorable atmospheric circulation to lower latitudes displacement of transient systems and, less frequently, the entry of Upper Tropospheric Cyclonic Vortex (UTCV).
Keywords: Renewable energy, Windpower generation, Northeastern Brazil, Trade winds, Madden-Julian Oscillation, Composities