Assessing Argentina's Heatwave Dynamics (1950-2022): A Comprehensive Analysis of Temporal and Spatial variability using ERA5-LAND

In the context of climate change, the escalation of temperature extremes and the persistence of heatwaves have become subjects of growing concern. This study examines Argentina's heatwave patterns from 1950 to 2022, using the ERA5-LAND dataset. The use of this dataset allows for a detailed exploration with high spatial resolution (0.1° x 0.1°) and temporal precision, facilitating regional analyses in countries with vast territories, such as Argentina. The investigation focuses on analyzing temporal and spatial variations through four key metrics: heatwave duration, frequency, mean, and maximum temperature. It also explores seasonal disparities, distinguishing between the Warm Season (WS) and Cold Season (CS), and delves into the influence of the ENSO cold and warm phases (La Niña,El Niño). We use 2-meter temperature data on an hourly basis to calculate daily maximum (Tx) and minimum (Tn) temperatures and detect heatwaves. Our findings reveal an overall escalation in heatwaves across the majority of Argentine regions. Southern Patagonia and the Northwest emerge as hotspots with the most significant upward trends in heatwave metrics, while the Litoral region (Northeast) experiences noteworthy increases, particularly in its northern areas. Conversely, the South of Buenos Aires province (Central region) exhibits decreasing trends in specific areas. Specifically, for Tn, the Warm Season (WS) highlights more significant positive trends in heatwave metrics in most regions, with South Patagonia and the Northwest consistently displaying increases in all metrics. However, for Tx, positive significant trends are observed in both Warm and Cold Seasons, with the North West registering increases in all metrics except Cold Season intensity. Furthermore, the study identifies variations in heatwave occurrences during El Niño and La Niña phases. La Niña events contribute to an increased heatwave frequency across all regions, as evidenced by Tn and Tx metrics. In Patagonia, La Niña amplifies all studied heatwave metrics for both temperature variables. Conversely, during El Niño months, heatwave intensities increase nationwide, excluding Patagonia. This comprehensive research contributes to existing knowledge by providing a detailed, high spatial resolution understanding of heatwave behavior, offering invaluable insights for adapting to extreme temperature events like heatwaves. 

Key words: extreme events, ERA5-LAND, reanalysis