Climate change in North Patagonian Andes: temperature and precipitation patterns

Abstract

This study analyzes climate change in the North Patagonian Andes (NPA), focusing on temperature and precipitation trends in the last three decades. Data were collected from 12 key meteorological stations to assess changes in mean annual temperatures and precipitation patterns. Precipitation characterization was analyzed in two 100 km West-East transects: La Angostura and Manso latitudinal transects. A consistent warming trend was identified in all stations, particularly at the Alerce station in the NPA, where temperatures increased by 0.82°C per decade since 1993. This warming trend was further emphasized by a steeper increase in the mean temperature trend starting in 2007, along with a rise in temperature anomalies and more frequent hot weather events. Additionally, there is a significant negative trend in both transects in the standardized precipitation index, with moderate and severe droughts becoming more common since 2016. Precipitation trends revealed a notable decline since 2007, especially in the Manso transect which was more affected by the westward retraction of precipitation isohyets in the last 5 years (2016-2021). These results indicate that the positive phase of the Southern Annular Mode (SAM), associated with a poleward movement of storm tracks, has contributed to warmer and drier conditions across much of NPA. The observed climate changes have significant implications for regional hydrology and ecosystem dynamics. These findings underscore the importance of monitoring and understanding the intricate relationships between atmospheric circulation patterns and local climate dynamics in the face of ongoing climate change.