Climate of the Marrakech High Atlas, Morocco: Temperature lapse rates and precipitation gradient from piedmont to summits

Abstract

Understanding mountain climates poses many challenges, because difficult terrain leads to a sparsity of weather stations and therefore poor data availability, meaning the detailed information required to understand these complex systems is lacking. Here, we analyze eleven years of half-hourly climate observations from the Joint International Laboratory LMI-TREMA (Télédétection et Ressources en Eau en Méditerranée semi-Aride) network of weather stations in the Marrakech High Atlas, Morocco, providing detailed information about the climate in this area. Our analysis shows the mean annual near-surface temperature lapse rate is −4.63°C km−1, with an uncertainty range of −4.39 to −4.85°C km−1, lower than the standard environmental temperature lapse rate. Mean temperature lapse rates vary from −3.67°C to −5.21°C km−1 monthly, and throughout the day from −2.75°C to −7.1°C km−1, which has important implications for understanding snowpack variations at the highest elevations. Understanding precipitation is inherently complex, but our analysis shows that mean annual precipitation increases by 166 mm km−1 (150.6 to 183.7 mm km−1) with a significant snow component at the highest elevations. This analysis improves our understanding of the mountain climate system with new regional temperate lapse rates and precipitation gradients, having the potential to improve gridded climatologies and climate models, with relevance for the wider High Atlas region.