• search hit 1 of 2
Back to Result List

Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes

  • Based on high-spatiotemporal-resolution data, the authors perform a climatological study of strong rainfall events propagating from southeastern South America to the eastern slopes of the central Andes during the monsoon season. These events account for up to 70% of total seasonal rainfall in these areas. They are of societal relevance because of associated natural hazards in the form of floods and landslides, and they form an intriguing climatic phenomenon, because they propagate against the direction of the low-level moisture flow from the tropics. The responsible synoptic mechanism is analyzed using suitable composites of the relevant atmospheric variables with high temporal resolution. The results suggest that the low-level inflow from the tropics, while important for maintaining sufficient moisture in the area of rainfall, does not initiate the formation of rainfall clusters. Instead, alternating low and high pressure anomalies in midlatitudes, which are associated with an eastward-moving Rossby wave train, in combination withBased on high-spatiotemporal-resolution data, the authors perform a climatological study of strong rainfall events propagating from southeastern South America to the eastern slopes of the central Andes during the monsoon season. These events account for up to 70% of total seasonal rainfall in these areas. They are of societal relevance because of associated natural hazards in the form of floods and landslides, and they form an intriguing climatic phenomenon, because they propagate against the direction of the low-level moisture flow from the tropics. The responsible synoptic mechanism is analyzed using suitable composites of the relevant atmospheric variables with high temporal resolution. The results suggest that the low-level inflow from the tropics, while important for maintaining sufficient moisture in the area of rainfall, does not initiate the formation of rainfall clusters. Instead, alternating low and high pressure anomalies in midlatitudes, which are associated with an eastward-moving Rossby wave train, in combination with the northwestern Argentinean low, create favorable pressure and wind conditions for frontogenesis and subsequent precipitation events propagating from southeastern South America toward the Bolivian Andes.show moreshow less

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Metadaten
Author:Niklas Boers, Henrique M. J. Barbosa, Bodo BookhagenORCiDGND, Jose A. Marengo, Norbert Marwan, Jürgen KurthsORCiDGND
DOI:https://doi.org/10.1175/JCLI-D-15-0137.1
ISSN:0894-8755 (print)
ISSN:1520-0442 (online)
Parent Title (English):Journal of climate
Publisher:American Meteorological Soc.
Place of publication:Boston
Document Type:Article
Language:English
Year of first Publication:2015
Year of Completion:2015
Release Date:2017/03/27
Tag:Cold air surges; Convective storms; Extreme events; Mesoscale systems; Precipitation; Subtropical cyclones
Volume:28
Issue:19
Pagenumber:18
First Page:7641
Last Page:7658
Funder:DFG/FAPESP [IRTG 1740/TRP 2011/50151-0]; Government of the Russian Federation [14.Z50.31.0033]; FAPESP Project Go Amazon [2013/50538-7]
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Erd- und Umweltwissenschaften
Peer Review:Referiert