Duration and number of rainfall events in Brazil

In this paper, the statistics of number and duration of rainfall events exceeding given thresholds, are investigated for four sites in Brazil. One of the sites is located within the Brazilian Amazonia: Belém (-1, super-humid equatorial). The other sites are located in Rio de Janeiro (-23, tropical), Curitiba (-25, subtropical-highlands) and Porto Alegre (-30, subtropical). Understanding the dynamics of rainfall should improve the statistical modelling of attenuation. Results include the parametric estimation of the cumulative distribution functions of rainfall events duration based on a Weibull distribution. These results indicate a clusterization of the shape parameter around several distinct rainfall threshold regions. The total number and duration of events are analysed using a modeling strategy based on second order exponentials. Average duration of events is modeled by an single order exponential model. The ruggedness of the average duration curves highlighted a clustering effect.