Esplorare il clima sul tetto del mondo: Un'analisi combinata di osservazioni in-situ e modelli sulle pendici superiori del Monte Everest

The Tibetan Plateau (TP) plays a crucial role in global water resources with the adjacent mountain ranges, ensuring a relatively constant water supply for more than 1.4 billion people. It is also the region where all “eight-thousanders” (peaks above 8000 m.a.s.l) are located. This last point has made it one of the most coveted climbing regions in the world but still one of the most dangerous. Its topography is complex, and the terrain is steep. Proper training and suitable mountaineering equipment are the only ways to mitigate risks related to such extreme expeditions. However, a substantial knowledge gap exists regarding these high-mountain areas due to limited observations of fundamental climate variables (e.g. temperature, wind, etc…). Consequently, creating safe and performing alpine equipment (e.g. mountaineering boots) consistent with on-site conditions becomes remarkably challenging. In this region, automatic weather stations that measure these variables are generally located in valleys. This is because installing and maintaining them at high elevations is demanding due to the harsh environmental conditions. This results in a biased distribution of measuring stations towards lower elevations and insufficient observational data at the elevations where climbers are most exposed. The most recent effort to address this observational gap occurred during the National Geographic and Rolex Perpetual Planet Expeditions in Spring 2019 and 2022. During these expeditions, a network of six automatic weather stations was deployed on the southern slopes of Mount Everest. For the first time, this study aims to provide realistic and reliable data on the climatic conditions observed at the summit of Mount Everest functional to the design of better alpine equipment in collaboration with SCARPA. The investigation applies robust quality control on the raw measurements to ensure their quality and reliability. The study delivers a synthesis of factual conditions found at different elevations in May (when most expeditions are carried out) and June (supposedly an unfavourable period for climbing due to the arrival of the monsoon), where most observations are available. Furthermore, the study conducts validation of the ERA5 reanalysis of temperature data. This is done by comparing it with year-round observations and correcting biases in a 30-year temperature series. This extends the analysis of temperatures on a climate normal (a 30-year average of a weather variable).