Dinámica Glaciar en un Contexto de Cambio Climático
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Examinando Dinámica Glaciar en un Contexto de Cambio Climático por Materia "Climate change"
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Ítem 1975–2018: 43 Years of Glacial Retreat in the Incachiriasca Glacier (Nevado Salcantay, Vilcabamba Range, Peru)(Springer International Publishing, 2023) Álvaro Navarro; Jose Úbeda; Jesús Gómez; Ramón PelliteroGlaciers are sensitive indicators of climate change, especially small sized tropical glaciers, since they are the most susceptible to any minimal variation of climatic conditions. This study focuses on the analysis of the shrinkage of the Incachiriasca II glacier (72º32’W, 13º21’S; ~ 4950 m) from 1975 to 2018. The first reference of the glacier’s delimitation is the annual topographies by Peruvian researchers between 2007 and 2018. This time sequence has been extended to 1975 by analysing 28 LANDSAT images. Our results show a loss of 51.4% (−0.271 km2) of the glacier’s total area: from 0.528 km2 (1975) to 0.257 km2 (2018), equivalent to −0.0063 km2yr−1 (1.2% yr−1). According to the observed trend, the annual rate of decline has increased considerably, especially since 2010, from 1% in 2001–2010 to 3% in 2010–2018.Ítem Annual Variability in the Cordillera Blanca Snow Accumulation Area Between 1988 and 2023 Using a Cloud Processing Platform(MDPI AG, 2025-06-13) Júlia Lopes Lorenz; Kátia Kellem da Rosa; Rafael da Rocha Ribeiro; Rolando Cruz Encarnación; Adina Racoviteanu; Federico Aita; Fernando Luis Hillebrand; Jesus Gomez Lopez; Jefferson Cardia SimõesTropical glaciers are highly sensitive to climate change, with their mass balance influenced by temperature and precipitation, which affects the accumulation area. In this study, we developed an open-source tool to map the accumulation area of glaciers in the Cordillera Blanca, Peru (1988–2023), using Landsat images, spectral indices, and the Otsu method. We analyzed trends and correlations between snow accumulation area, meteorological patterns from ERA5 data, and oscillation modes. The results were validated using field data and manual mapping. Greater discrepancies were observed in glaciers with debris cover or small clean glaciers (<1 km2). The Amazonian and Pacific sectors showed a significant trend in decreasing accumulation areas, with reductions of 8.99% and 10.24%, respectively, from 1988–1999 to 2010–2023. El Niño events showed higher correlations with snow accumulation, snowfall, and temperature during the wet season, indicating a stronger influence on the Pacific sector. The accumulation area was strongly anti-correlated with temperature and correlated with snowfall in both sectors at a 95% confidence level (α = 0.05). The highest correlations with meteorological parameters were observed during the dry season, suggesting that even minor changes in temperature or precipitation could significantly impact the accumulation area.Ítem The Energy and Mass Balance of Peruvian Glaciers(Journal of Geophysical Research: Atmospheres, 2021) Fyffe, Catriona L.; Potter, Emily; Fugger, Stefan; Orr, Andrew; Fatichi, Simone; Loarte, Edwin; Medina, Katy; Hellström, Robert Å.; Bernat, Maud; Aubry-Wake, Caroline; Gurgiser, Wolfgang; Perry, L. Baker; Suarez, Wilson; Quincey, Duncan J.Abstract Peruvian glaciers are important contributors to dry season runoff for agriculture and hydropower, but they are at risk of disappearing due to climate change. We applied a physically based, energy balance melt model at five on-glacier sites within the Peruvian Cordilleras Blanca and Vilcanota. Net shortwave radiation dominates the energy balance, and despite this flux being higher in the dry season, melt rates are lower due to losses from net longwave radiation and the latent heat flux. The sensible heat flux is a relatively small contributor to melt energy. At three of the sites the wet season snowpack was discontinuous, forming and melting within a daily to weekly timescale, and resulting in highly variable melt rates closely related to precipitation dynamics. Cold air temperatures due to a strong La Niña year at Shallap Glacier (Cordillera Blanca) resulted in a continuous wet season snowpack, significantly reducing wet season ablation. Sublimation was most important at the highest site in the accumulation zone of the Quelccaya Ice Cap (Cordillera Vilcanota), accounting for 81% of ablation, compared to 2%?4% for the other sites. Air temperature and precipitation inputs were perturbed to investigate the climate sensitivity of the five glaciers. At the lower sites warmer air temperatures resulted in a switch from snowfall to rain, so that ablation was increased via the decrease in albedo and increase in net shortwave radiation. At the top of Quelccaya Ice Cap warming caused melting to replace sublimation so that ablation increased nonlinearly with air temperature.