versión On-line ISSN 1850-468X
SAROCHAR, Rubén H.; CIAPPESONI, Héctor H. y RUIZ, Nora E.. Convective and stratiform precipitation in the Humid Pampas: a separation approach and climatological aspects. Meteorologica [online]. 2005, vol.30, n.1-2, pp. 77-88. ISSN 1850-468X.
Precipitation data at ten stations located in the Argentine Humid Pampas region since January 1995 to December 2001 have been studied. For each daily rainfall observation, contributions to precipitation coming from convective cloudiness and non-showery or stratus clouds have been separated. Hourly present weather reports from SYNOP information related to convection were used to discriminate convective rainy days from stratiform ones. For annual precipitation in the humid pampas, on average, convective precipitation frequency is less than stratiform frequency (45% an 55%, respectively); the opposite happens with the precipitation amount: 75% has convective origin and the remaining 25%, non-showery one. Monthly convective precipitation and its corresponding occurrence frequency are higher than the respective stratiform ones during the warm season (November to April) with the main maximum between January and April, and the secondary one at October or November depending on the station. The precipitation annual march shows a strong decrease in the cold months. This little rainfall is mainly form stratiform source. The annual wave is in a great extent defined by the annual convective wave. According to precipitation variability, monthly standard deviations increase in autumn and spring, and they are higher for convection. Stratus-type rainfall variability is less.
Palabras clave : Convective precipitation; Stratiform precipitation; Humid pampas.