Investigating dynamical features in the long-term daily maximum temperature time series recorded at Adrián Jara, Paraguay

Abstract

In this study, we analyse the daily series of maximum temperature measured at Adrian Jara, Paraguay, to disclose features possibly linked with climatological indices that are thought to regulate, in general, the climatic variability of South America. This station is well suited to perform this investigation because it is located in a rural not urbanized area. Our findings reveal that the analyzed series is modulated by several cycles: the annual and half-annual cycle; the 8-year cycle that could be driven by 8-year cycle of the baroclinic waves at the Southern Hemisphere; the 2–3-year periodicity, which seems linked with the Pacific Decadal Oscillation; the 15–16 years periodicity that seems to be induced by the low-frequency fluctuations of SST in the North Atlantic. It is also found an apparent shift in the maximum temperature in the late 1989 that seems to be in agreement with similar findings by other studies that documented such potential jump in the climate system.