The understanding of global warming influences on the temperature behaviour on mountainous areas

The temperature behavior in mountainous regions at mid-latitudes is particularly susceptible to the effects of global warming. Within this context, it is crucial to comprehend and quantify the influence of changes in synoptic patterns at higher resolution scales. This study focuses on a Pyrenean valley (north-east of Iberian Peninsula) prone to the formation of cold air pools (CAPs). It is established that CAPs predominantly form under stable conditions. However, deep and enclosed valleys frequently encounter decoupling situations, leading to unexpected variations in climatological temperature profiles. Consequently, understanding how global warming will impact temperatures at various altitudes in the context of Elevation Dependent Warming becomes increasingly challenging.

In this study, two temperature transects have been utilized: one covering a closed valley prone to CAP formation and one in an open valley with drainage. Each transect is composed of six temperature and humidity sensors taking data every 30 minutes, covering a range of heights of approximately 1200 m between altitudes of 1000 m and 2200 m. The sensors were set up in 2011 and have been recording data since then, which allows for a first approximation of climate trends in mid-latitude mountain ranges.

In contrast with applying purely statistical relationships based on correlations, in this case, a causal approach has been adopted to quantify how the anticipated synoptic variability is transmitted to the differences between the vertical temperature profiles previously defined. After constructing some causal relationships among variables, this has been utilized to infer changes in CAP behavior under different climate change scenarios. This methodology offers a robust framework for assessing the potential impacts of global warming on mountainous regions, providing valuable insights for future climate adaptation and mitigation efforts.