SIGNAL OF THE ENSO PHENOMENON IN THE WESTERN PARANÁ REGION RAINFALL

• Autor(a) principal: Pedron, Isabel Tamara
• Data de Publicação: 2023
• Outros Autores: Limberger, Leila
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Ra'e Ga (Online)
• Texto Completo: https://revistas.ufpr.br/raega/article/view/92382
• topic: Climatologia; Climate; modes; Precipitation; ONI; Wavelets

One of the modulators of variability in the precipitation pattern in the Brazilian southern region is the El Niño/Southern Oscillation (ENSO) phenomenon, the focus of this study, which aimed to investigate the influence of ENSO in western Paraná, Southern Brazil. The complexity of manifestation on a local scale (precipitation) of a phenomenon on a global scale (ENSO) was evaluated. The study was developed using monthly rainfall series for Cascavel, Toledo, Palotina, Foz do Iguaçu, and Guaíra. The results indicated that there is no uniform behavior across the region for signal identification of the effects of ENSO events. Only Cascavel and Palotina showed a significant Spearman correlation between monthly accumulated precipitation and the ONI index (Oceanic Niño Index), not only in paired data (same month) but also lagged from one to four months. On the other hand, the wavelet analysis indicated the signal of the ENSO phenomenon in the rainfall data, highlighting the peak in periods from two to seven years in the power spectrum for Cascavel, Foz do Iguaçu, and Palotina. In the wavelet coherence analysis, all locations exhibited a correlation between the ONI index and the monthly rainfall, over the period of around four years. This work highlights the complexity of the manifestation of ENSO on a local scale, considering that the climate variability of the analyzed cities does not respond only to this variability modulator, and being necessary to consider other oceanic areas and other local factors that generate variability, highlighting the challenge posed for the weather forecast.