Authors: Pedro Amaral Reis*, Centro Polar e Climático - UFRGS, Venisse Schossler, Centro Polar e Climático - UFRGS, Francisco Eliseu Aquino, Centro Polar e Climático - UFRGS, Ronaldo Torma Bernardo, Centro Polar e Climático - UFRGS, Jefferson Cardia Simões, Centro Polar e Climático - UFRGS
Topics: Climatology and Meteorology, South America
Keywords: Cyclogenesis, Amazon, South American Low-Level Jet, Antarctica
Session Type: Poster
Presentation File: No File Uploaded
The intensity and the source of precipitated water of a cyclogenesis in Rio Grande do Sul, Brazil, is explored through isotopic composition and synoptic analysis. The extratropical cyclone generated disasters due to the associated windstorm and hail. For isotopic analysis, cavity ring-down spectroscopy are performed with rainwater from Porto Alegre, Rio Grande do Sul. Atmospheric environment analysis are illustrated using CFSv2/NCEP reanalysis with temperature, geopotential height, meridional and zonal wind, specific humidity and mean sea level pressure variables, between September 11th and 13th, 2016. Additionally, the representativeness of the event in the monthly precipitation are quantified from the automatic weather station of Porto Alegre (A801). The event resulted in 32.3 mm of precipitation, which represented 35.6% of the monthly accumulated and with an isotopic signature of δ18O = 1.08‰. The Low-Level Jet was classified as LLJ-3 and as Chaco Jet Event. The intensification of the cyclogenesis generated an explosive cyclone with 1.27 NDRc and vertical development identified at high levels (250 hPa). The humidity which sustained the event has an Amazonian source, carried by the Low-Level Jet. The coupling between the Low-Level Jet and Jet Streams associated with the passage of a cold front intensified the cyclogenesis and favored the quick development of an explosive cyclone.
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