Analysis of RegCM3 generated weather regimes over central Brazil: a case study in Distrito Federal

作者：Tanaka da Anunciacao Yumiko Marina; da Rocha Rosmeri Porfirio; Walde Detlef Hans Gert

来源：Environmental Earth Sciences, 2014, 72(12): 4849-4862.

DOI：10.1007/s12665-014-3340-4

• Summer precipitation
• Central Brazil
• Kohonen maps
• RegCM3
• Weather regimes

Low level atmospheric circulations downscaled by regional climate model are used to identify austral summer (December-January-February) weather regimes (WRs) over central Brazil. For the period 1989-2006, the Kohonen%26apos;s self-organizing maps method is applied to provide simulated weather patterns and their relationship with daily rainfall. Six WRs were defined: two related to the active phase of the South American monsoon system (SAMS), with the large occurrence of days with extreme rainfall; two related to the break phase and few occurrences of extreme rainfall; and two others resembling transient WRs, those with fewer extreme rainfall. The WRs formed a cycle obtained from their transition probabilities, which suggests alternating phases of the convergence zone and their association with extreme rainfall. Thus, the variability of summer precipitation, related to the behavior of the simulated WRs enables the verification of the regional dynamic model on intraseasonal time scale.

• 出版日期2014-12