PRESENT CLIMATE OF LAKE MONTCORTES (CENTRAL PYRENEES): PALEOCLIMATIC RELEVANCE AND INSIGHTS ON FUTURE WARMING

The varved sediments of the Pyrenean Lake Montcortes (Pallars Sobira, Lleida) embody a unique continuous high-resolution (annual) paleoarchive of the last 3000 years for the circum-Mediterranean region. A variety of paleoclimatic and paleoecological records have been retrieved from these uncommon sediments that have turned the lake into a regional reference. Present-day geographical, geological, ecological and limnological features of the lake and its surroundings are reasonably well known but the lack of a local weather station has prevented characterization of current climate, which is important to develop modern-analog studies for paleoclimatic reconstruction and to forecast the potential impacts of future global warming. Here, the local climate of the Montcortes area for the period 1955-2020 is characterized using a network of nearby stations situated along an elevational transect in the same river basin of the lake. The finding of statistically significant elevational gradients for average temperature and precipitation (-0.59 & DEG;C and 82 mm per 100 m elevation, respectively) has enabled to estimate these parameters and their seasonal regime for the lake site. The estimated average annual temperature is 9.7 & PLUSMN;0.8 & DEG;C and the estimated total annual precipitation is 1031 & PLUSMN;34 mm, in average. A representative climograph has been shaped with these data that can serve as a synthetic descriptive and comparative climatic tool. The same analysis has provided climatic data for modern-analog studies useful to improve the interpretation of sedimentary records in climatic and ecological terms. In addition, the seasonal slope shifting of the climatic elevational gradients has been useful to gain insights about possible future climatic trends under a warming scenario.

Automated summary

The varved sediments of Lake Montcortes provide a valuable paleoarchive for the circum-Mediterranean region. However, the lack of local climate data has hindered the understanding of current climate and its implications for paleoclimatic reconstruction and future global warming.