Analysis of climate variability and teleconnection patterns in Sierra de Guadarrama (Iberian Peninsula) using 120-year observed and reconstructed time series

Mountains play a crucial role in the climate system at various temporal and spatial scales. Additionally, they serve as vital sources of resources, such as fresh water, and host a diverse range of biodiversity. This influence on development and natural ecosystems is particularly significant in semi-arid regions like the Sierra de Guadarrama. This mountain range is located in the Iberian Peninsula and has been the subject of official meteorological observations since the mid-20th century. Nevertheless, there is a gap in the knowledge of the rainfall and temperature variability and its drivers in this important region. TROPA-UCM group has been intensively observing and studying this range since 1998 and recently, a methodology has been developed to extend the observations from 1900 to present using data from the ERA20C and in-situ observations. This has enabled longer time series and a deeper analysis of large-scale teleconnection patterns and climate variability, unlike ever before. The analysis includes trends in temperature, snow precipitation, and snowpack duration. Variations in precipitation and temperature have been identified, providing valuable information for estimating potential changes in seasonal runoff and rainfall intensity. This information can be of great use to organizations responsible for the management of this area, for developing adaptation strategies for new scenarios and to improve seasonal to decadal predictions.