In this study, we analyse the daily series of maximum temperature measured at Adrián 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.
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Satellite-based precipitation estimates represent a potential alternative source of input data in a plethora of meteorological and hydrological applications, especially in regions characterized by a low density of rain gauge stations. Paraguay provides a good example of a case where the use of satellite-based precipitation could be advantageous. This study aims to evaluate the version 7 of the Tropical Rainfall Measurement Mission Multi-Satellite Precipitation Analysis (TMPA V7; 3B42 V7) and the version 1.0 of the purely satellite-based product of the Climate Prediction Center Morphing Technique (CMORPH RAW) through their comparison with daily in situ precipitation measurements from 1998 to 2012 over Paraguay. The statistical assessment is conducted with several commonly used indexes. Specifically, to evaluate the accuracy of daily precipitation amounts, mean error (ME), root mean square error (RMSE), BIAS, and coefficient of determination (R2) are used, and to analyze the capability to correctly detect different precipitation intensities, false alarm ratio (FAR), frequency bias index (FBI), and probability of detection (POD) are applied to various rainfall rates (0, 0.1, 0.5, 1, 2, 5, 10, 20, 40, 60, and 80 mm/day). Results indicate that TMPA V7 has a better performance than CMORPH RAW over Paraguay. TMPA V7 has higher accuracy in the estimation of daily rainfall volumes and greater precision in the detection of wet days (> 0 mm/day). However, both satellite products show a lower ability to appropriately detect high intensity precipitation events.
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