author = "Gomes, Helber Barros and Ambrizzi, T{\'e}rcio and Herdies, Dirceu 
                         Luis and Hodges, Kevin and Silva, Bruce Francisco Pontes da",
          affiliation = "{Universidade de S{\~a}o Paulo (USP)} and usp and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {University of 
                         Reading} and {Capixaba Institute of Research}",
                title = "Easterly wave disturbances over northeast Brazil: an observational 
              journal = "Advances in Meteorology",
                 year = "2015",
               volume = "2015",
               number = "ID 176238",
             abstract = "This paper aims to identify the circulation associated with 
                         Easterly Wave Disturbances (EWDs) that propagate toward the 
                         Eastern Northeast Brazil (ENEB) and their impact on the rainfall 
                         over ENEB during 2006 and 2007 rainy seasons (April-July). The 
                         EWDs identification and trajectory are analyzed using an automatic 
                         tracking technique (TracKH). The EWDs circulation patterns and 
                         their main features were obtained using the composite technique. 
                         To evaluate the TracKH efficiency, a validation was done by 
                         comparing the EWDs number tracked against observed cases obtained 
                         from an observational analysis. The mean characteristics of EWDs 
                         are 5.5-day period, propagation speed of similar to 9.5 m.s(-1), 
                         and a 4500 km wavelength. A synoptic analysis shows that between 
                         days -2 d and 0 d, the low level winds presented cyclonic relative 
                         vorticity and convergence anomalies both in 2006 and 2007. The 
                         EWDs signals are strongest at low levels. The EWDs propagation is 
                         associated with relative humidity and precipitation positive 
                         anomalies and OLR and omega negative anomalies. The EWDs tracks 
                         are seen over all ENEB and their lysis occurs between the ENEB and 
                         marginally inside the continent. The tracking captured 71% of EWDs 
                         in all periods, indicating that an objective analysis is a 
                         promising method for EWDs detection.",
                  doi = "10.1155/2015/176238",
                  url = "http://dx.doi.org/10.1155/2015/176238",
                 issn = "1687-9309",
             language = "en",
        urlaccessdate = "25 nov. 2020"