Assessing Argentina's heatwave dynamics (1950–2022): a comprehensive analysis of temporal and spatial variability using ERA5-LAND.

Understanding the spatial and temporal variability of heatwaves is crucial for climate change adaptation. This study examines heatwaves in Argentina from 1950 to 2022, analyzing temporal and spatial changes using four metrics: number of events (E), duration (D), mean intensity (MnI), and maximum intensity (MxI). It investigates seasonal variations (Warm and Cold Seasons—CS, WS) and the influence of different phases of the El Niño-Southern Oscillation (ENSO). Data from ERA5-LAND Reanalysis for 2 m daytime (Tx) and nighttime (Tn) temperatures are utilized. Our findings reveal regions with significantly higher heatwave intensities (Tx) in the North, east of Cuyo, west of Centro, and Southern Patagonia. Conversely, significant heatwave intensities (Tn) were observed, particularly in the north of the Litoral and Southern Patagonia. The Andes region (center and north) exhibited significant intensities for Tn. Both D and E exhibited similar significant trends for both Tn and Tx, except for the central zone. During the WS, the North-West and South Patagonia exhibit significant increasing trends for across most metrics. In contrast, during the CS, a higher number of significant increases in the studied metrics were observed in relation to Tx. El Niño amplifies heatwave intensities nationwide, except in Patagonia, where this occurs during the cold phase. In this phase, E and D of events increase in most Argentinian regions, resulting in a decoupling of intensity and duration, which increases in opposite periods. This study contributes to existing research by providing a detailed understanding of heatwave behavior with high spatial resolution. [ABSTRACT FROM AUTHOR]