The relation between thermodynamic instability indexes, precipitable water content, static energy flux, and rainfall annual cycle over Maxaranguape (coastland site, Rio Grande do Norte, Northeast of Brazil) was investigated. The radiosonde dataset covered the period from January 2002 to December 2009 within the South Hemisphere ADditional OZonesondes (SHADOZ) project. The thermodynamics indexes variability do not explain the maximum rainfall in July, however they are in phase with the secondary maximum in April. The annual cycle of the moist and saturated static energy fluxes showed that rainfall cycle is modulated by both thermodynamics and low level moisture convergence mechanisms.
moisture convergence; SHADOZ; radiosonde