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

Niklas Boers, Henrique J Barbosa, Bodo Bookhagen, Jose A Marengo, Nobert Marwan, Jurgen Kurths

Research output: Contribution to journalArticle

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Abstract

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 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.
Original languageEnglish
Pages (from-to)7641-7658
Number of pages18
JournalJournal of climate
Volume28
Issue number19
Early online date29 Sep 2015
DOIs
Publication statusPublished - 1 Oct 2015

Fingerprint

rainfall
moisture
frontogenesis
natural hazard
Rossby wave
train
low pressure
landslide
inflow
monsoon
anomaly
South America
tropics

Keywords

  • cold air surges
  • extreme events
  • precipitation
  • subtropical cyclones
  • convective storms
  • mesoscale systems

Cite this

Boers, N., Barbosa, H. J., Bookhagen, B., Marengo, J. A., Marwan, N., & Kurths, J. (2015). Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes. Journal of climate, 28(19), 7641-7658. https://doi.org/10.1175/JCLI-D-15-0137.1

Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes. / Boers, Niklas; Barbosa, Henrique J; Bookhagen, Bodo; Marengo, Jose A; Marwan, Nobert; Kurths, Jurgen.

In: Journal of climate, Vol. 28, No. 19, 01.10.2015, p. 7641-7658.

Research output: Contribution to journalArticle

Boers, N, Barbosa, HJ, Bookhagen, B, Marengo, JA, Marwan, N & Kurths, J 2015, 'Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes', Journal of climate, vol. 28, no. 19, pp. 7641-7658. https://doi.org/10.1175/JCLI-D-15-0137.1
Boers N, Barbosa HJ, Bookhagen B, Marengo JA, Marwan N, Kurths J. Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes. Journal of climate. 2015 Oct 1;28(19):7641-7658. https://doi.org/10.1175/JCLI-D-15-0137.1
Boers, Niklas ; Barbosa, Henrique J ; Bookhagen, Bodo ; Marengo, Jose A ; Marwan, Nobert ; Kurths, Jurgen. / Propagation of Strong Rainfall Events from Southeastern South America to the Central Andes. In: Journal of climate. 2015 ; Vol. 28, No. 19. pp. 7641-7658.
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