Revista Brasileira de Meteorologia
Print version ISSN 0102-7786
SILVA, Cláudio Moisés Santos e; FREITAS, Saulo Ribeiro de and GIELOW, Ralf. Diurnal cycle of the precipitation estimated by a S-band radar, and the 3B42_V6 algorithm of the TRMM project during the rainy season of 1999 over southwestern of the Amazon. Rev. bras. meteorol. [online]. 2011, vol.26, n.1, pp.95-108. ISSN 0102-7786. http://dx.doi.org/10.1590/S0102-77862011000100009.
The rainfall estimated with a S-band radar, and by the 3B42_V6 TRMM satellite algorithm, is evaluated by comparing it with rain gauge measurements during the 1999 rainy season in the Amazon Basin, with focus on the diurnal cycle. Statistic analyses based on contingency tables, skill scores, and harmonic analysis were used. The radar estimation is in agreement with the rain gauges measurements. The diurnal cycle exhibits a main maximum during the afternoon and a secondary one at night, which is associated to Squall Lines propagation over the Amazon Basin. It is also shown that the 3B42_V6 algorithm captured important features of the rainfall diurnal cycle: (i) the maximum at 2100 UTC (1700 LST); (ii) the nocturnal rainfall is strongest during Westerly regimes. These results are important for numerical weather and climate prediction model evaluation, especially when concerning the convection activity over the region.
Keywords : TRMM-LBA; Harmonic Analysis; Intraseasonality..