Forest fires release large amounts of atmospheric pollutants, which can be carried by the wind to remote regions, such as glaciers, altering their surface properties. This study assesses the influence of a record number of forest fires on the concentrations of total particulate matter on the glacier surface (TPM), light-absorbing particles (LAP), and albedo, comparing these parameters with those recorded during recent snowfall events.
Sixteen snow and ice samples were collected along an altitudinal profile. In the laboratory, the total particle concentrations were determined, and the LAMH method was used for LAP quantification. Additionally, low-cost sensors were installed on the glacier surface to monitor the variation of albedo along an altitudinal gradient.
During the study period, 396 forest fires were recorded in the Cordillera Blanca region. The TPM on the glacier surface ranged between 140 and 1355 g/m², with a mean of 655 g/m², while LAP concentrations varied from 472 to 683 µg/m², reaching an average of 573.25 µg/m². Consequently, albedo values ranged between 0.21 and 0.48 (mean: 0.35). In contrast, during snowfall episodes, significantly lower TPM values were observed (range: 0.14–1.32 g/m²; mean: 0.45 g/m²) and LAP (range: 13.8–38.6 µg/m²; mean: 21.85 µg/m²), accompanied by a progressive increase in albedo in fresh snow (range: 0.61–0.73; mean: 0.68).
The results indicate that the deposition of TPM and LAP associated with forest fires exceeds, respectively, more than 30,000 and 40 times the concentrations observed during snowfall events, which could favor an accelerated glacier melting process due to the decrease in albedo and the consequent increase in radiation absorption.