Concentration of Black Carbon (BCe) in snow, glacier ice, and glacier water from high mountains in central Mexico and central Andes (Peru and Bolivia)

Abstract

We measure the total optical radiative effect of the sediments (light-absorbing particles) present in surface snow (30 cm), glacier ice, and water samples collected at several high mountains: Iztaccíhuatl and Citlaltépetl in central Mexico; Vallunaraju in Cordillera Blanca, Peru; Condoriri, Huayna Potosi, and Ilimani in Cordillera Real, Bolivia, using a light-absorbing method. This method consists of shining a controlled amount of light on a filter that contains the sediments (light-absorbing particles) from the samples. Different types of light-absorbing particles (LAPs) darken snow surfaces, enhancing snowmelt on glaciers and snowfields. LAPs are often a mixture of biotic and abiotic components at the snow surface, yet methods to separate their respective abundance and albedo-reducing effects are lacking. As more sediments are present on the filter, a more significant amount of light is absorbed. It is important to note that this method does not directly measure the content of black carbon (BC) but, in general, of light-absorbing particles (LAP) without distinguishing between them, and it quantifies the content as equivalent to black carbon (BCe). For all the locations, the snow samples present an average of 1400 ng/g BCe; for the water samples, 1100 ng/g BCe; and for the ice samples, 450 ng/g BCe. For all the samples, a minimum of 12 ng/g BCe and a maximum of 2678 ng/g BCe, corresponding to Vallunaraju (Peru) and Iztaccíhuatl (México), respectively, were measured. Finally, we used the NOAA HYSPLIT Model to trace the possible' backward trajectories at the three localities. The concentrations measured in this BCe work are comparable to those reported in other parts of the world.