Abstract

The Central Andes (CA) of Argentina and Chile (30°S and 40°S), includes the largest glaciated areas in South America (SA) outside southern Patagonia. This water reserve is relevant because it is the main water source of the largest metropolitan area in Chile, Santiago and the fourth largest city in Argentina, Mendoza. According to climate predictions, this region would be greatly affected by climate change, which would cause an alteration in the relationships between liquid and solid precipitation, albedo variations, changes in the seasonal distribution of Andean river spills, and overtaking in the runoff peaks. Due to the possible socioeconomic impacts in the region, it is necessary to design and implement adaptation strategies for these anticipated changes. An accurate prediction requires a correct representation of atmospheric conditions, their development and evolution. Recent studies conducted by our research group show that the presence of atmospheric aerosols would be related to the negative trend variations of snow albedo during the last almost 20 years, which leads to an increasing the snowmelt. Besides, there is a high degree of uncertainty about the identification and characterization of the light absorbing particles (LAP) as Black carbon (BC) that contribute the most to the decrease of the albedo and, therefore, to the snow darkening effect, and open burning in SA is an important LAP source that can reach hundreds of km from its generation source. In addition, these particles, depending on their size, quantity and chemical composition, could modify the constitution of the clouds, reducing the precipitation of rain or snow and increasing the formation of hail. The physics and dynamics of this type of events can be understood through the use of mesoscale models. In this work, inventories of regional anthropogenic emissions of own elaboration and inventory of burning of high resolution are incorporated to the simulations carried out with the WRF-Chem model to study the relationships: LAP spatial distributions – snow albedo. The partial results show that air masses from Brazil and northern Argentina are reaching the snowy areas of the CA and at the same time there is a snow albedo decrease. The results suggest that the LAP from the open field biomass burning are being deposited on the snow and decreasing it albedo, which produces a negative impact on snow and hydrological resources generated in the CA.