Nilton Montoya

Bio: Nilton Montoya is an academic researcher from National University of Saint Anthony the Abbot in Cuzco. The author has contributed to research in topics: Glacier & Precipitation. The author has an hindex of 3, co-authored 5 publications receiving 70 citations.

The freezing level in the tropical Andes, Peru: An indicator for present and future glacier extents

Abstract: Along with air temperatures, the freezing level height (FLH) has risen over the last decades. The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the FLH, mainly due to a decrease in accumulation and increase of energy for ablation caused by reduced albedo. Knowledge of future changes in the FLH is thus crucial to estimating changes in glacier extents. Since in situ data are scarce at altitudes where glaciers exist (above ~4800 m above sea level (asl)), reliable FLH estimates must be derived from multiple data types. Here we assessed the FLHs and their spatiotemporal variability, as well as the related snow/rain transition in the two largest glacier-covered regions in Peru by combining data from two climate reanalysis products, Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar Bright Band data, Micro Rain Radar data, and meteorological ground station measurements. The mean annual FLH lies at 4900 and 5010 m asl, for the Cordillera Blanca and Vilcanota, respectively. During the wet season, the FLH in the Cordillera Vilcanota lies ~150 m higher compared to the Cordillera Blanca, which is in line with the higher glacier terminus elevations. Coupled Model Intercomparison Project version 5 (CMIP5) climate model projections reveal that by the end of the 21st century, the FLH will rise by 230 m (±190 m) for Representative Concentration Pathway (RCP) 2.6 and 850 m (±390 m) for RCP8.5. Even under the most optimistic scenario, glaciers may continue shrinking considerably, assuming a close relation between FLH and glacier extents. Under the most pessimistic scenario, glaciers may only remain at the highest summits above approximately 5800 m asl.

Characteristics of Precipitating Storms in Glacierized Tropical Andean Cordilleras of Peru and Bolivia

Abstract: Precipitation variability in tropical high mountains is a fundamental yet poorly understood factor influencing local climatic expression and a variety of environmental processes, including glacier ...

Radar-Observed Characteristics of Precipitation in the Tropical High Andes of Southern Peru and Bolivia

Abstract: This study investigates precipitation delivery using the first detailed radar measurements of the vertical structure of precipitation obtained in the tropical Andes of southern Peru and Bolivia. A vertically pointing 24.1 GHz Micro Rain Radar in Cusco, Peru (3,350 m asl, August 2014-February 2015) and La Paz, Bolivia (3,440 m asl, October 2015-February 2017) provided continuous 1-min profiles of reflectivity and Doppler velocity during the respective time periods. Additional datasets collected include thermodynamic profiles from rawinsonde releases, hourly observations of various meteorological variables, and backward air trajectories from the NOAA HYSPLIT model. The vertically-pointing radar time-height data reveal a bimodal diurnal cycle in precipitation with cellular convection predominant in the afternoon and stratiform precipitation predominant overnight. Backward air trajectories for two stratiform case studies indicate that low-level flow originated in the Amazon basin three days prior to the events. Median melting layer heights were above the altitude of nearby glacier termini (~5,000 m) approximately 17% of the time in Cusco and 30% of the time in La Paz, indicating that some precipitation is falling as rain rather than snow on nearby glacier surfaces. Melting layer heights were highest in La Paz during the 2015-16 El Nino (47% above 5,000 m).

Iniciación de un monitoreo del balance de masa en el glaciar Suyuparina, Cordillera Vilcanota, Perú

Abstract: Filiacion institucional de autor: Alejo Cochachin Rapre /Autoridad Nacional del Agua - Unidad de Glaciologia y Recursos Hidricos (ANA-UGRH), Huaraz, Peru

Climate change research in bilateral development programmes: experiences from India and Peru

Abstract: This article reflects on the merits and shortfalls of bilateral research programmes aimed at strengthening climate change research capabilities, using the experience from two programmes, the PACC and IHCAP in Peru and India, respectively. The study highlights key aspects of these types of bilateral programmes, namely: capacity; performance, salary and appreciation; funding; bureaucracy and hierarchy; publishing; and data sharing. Furthermore, it emerged that these programmes would benefit from a more extensive consolidation phase of the research activities and partnership rather than rapidly transferring into out- and up-scaling phases.

Glacial areas, lakes areas, and snowlines from 1975-2012: Status of the Cordillera Vilcanota, including the Quelccaya Ice Cap, northern central Andes, Peru

Abstract: Glaciers in the tropical Andes of southern Peru have received limited attention compared to glaciers in other regions (both near and far), yet remain of vital importance to agriculture, fresh water, and hydropower supplies of downstream communities. Little is known about recent glacial-area changes and how the glaciers in this region respond to climate changes, and, ultimately, how these changes will affect lake and water supplies. To remedy this, we have used 158 multi-spectral satellite images spanning almost 4 decades, from 1975 to 2012, to obtain glacial- and lake-area outlines for the understudied Cordillera Vilcanota region, including the Quelccaya Ice Cap. Additionally, we have estimated the snow-line altitude of the Quelccaya Ice Cap using spectral unmixing methods. We have made the following four key observations: first, since 1988 glacial areas throughout the Cordillera Vilcanota (1988 glacial area: 361 km 2 ) have been declining at a rate of 3.99 ± 1.15 km 2 yr −1 (22 year average, 1988–2010, with 95% confidence interval (CI), n = 8 images). Since 1980, the Quelccaya Ice Cap (1980 glacial area: 63.1 km 2 ) has been declining at a rate of 0.57 ± 0.10 km 2 yr −1 (30 year average, 1980–2010, with 95% CI, n = 14). Second, decline rates for individual glacierized regions have been accelerating during the past decade (2000–2010) as compared to the preceding decade (1988–1999) with an average increase from 37.5 to 42.3 × 10 −3 km 2 yr −1 km −2 (13%). Third, glaciers with lower median elevations are declining at higher rates than those with higher median elevations. Specifically, glaciers with median elevations around 5200 m a.s.l. are retreating to higher elevations at a rate of ~1 m yr −1 faster than glaciers with median elevations around 5400 m a.s.l. Fourth, as glacial regions have decreased, 77% of lakes connected to glacial watersheds have either remained stable or shown a roughly synchronous increase in lake area, while 42% of lakes not connected to glacial watersheds have declined in area (58% have remained stable). Our new and detailed data on glacial and lake areas over 37 years provide an important spatiotemporal assessment of climate variability in this area. These data can be integrated into further studies to analyze inter-annual glacial and lake-area changes and assess hydrologic dependence and consequences for downstream populations.

Toward an imminent extinction of Colombian glaciers

Abstract: This study documents the current state of glacier coverage in the Colombian Andes, the glacier shrinkage over the twentieth century and discusses indication of their disappearance in the coming decades. Satellite images have been used to update the glacier inventory of Colombia reflecting an overall glacier extent of about 42.4 ± 0.71 km2 in 2016 distributed in four glacierized mountain ranges. Combining these data with older inventories, we show that the current extent is 36% less than in the mid-1990s, 62% less than in the mid-twentieth century and almost 90% less than the Little Ice Age maximum extent. Focusing on Nevado Santa Isabel (Los Nevados National Park), aerial photographs from 1987 and 2005 combined with a terrestrial LiDAR survey show that the mass loss of the former ice cap, which is nowadays parceled into several small glaciers, was about −2.5 m w.e. yr−1 during the last three decades. Radar measurements performed on one of the remnant glaciers, La Conejeras glacier, show that the i...

The freezing level in the tropical Andes, Peru: An indicator for present and future glacier extents

Abstract: Along with air temperatures, the freezing level height (FLH) has risen over the last decades. The mass balance of tropical glaciers in Peru is highly sensitive to a rise in the FLH, mainly due to a decrease in accumulation and increase of energy for ablation caused by reduced albedo. Knowledge of future changes in the FLH is thus crucial to estimating changes in glacier extents. Since in situ data are scarce at altitudes where glaciers exist (above ~4800 m above sea level (asl)), reliable FLH estimates must be derived from multiple data types. Here we assessed the FLHs and their spatiotemporal variability, as well as the related snow/rain transition in the two largest glacier-covered regions in Peru by combining data from two climate reanalysis products, Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar Bright Band data, Micro Rain Radar data, and meteorological ground station measurements. The mean annual FLH lies at 4900 and 5010 m asl, for the Cordillera Blanca and Vilcanota, respectively. During the wet season, the FLH in the Cordillera Vilcanota lies ~150 m higher compared to the Cordillera Blanca, which is in line with the higher glacier terminus elevations. Coupled Model Intercomparison Project version 5 (CMIP5) climate model projections reveal that by the end of the 21st century, the FLH will rise by 230 m (±190 m) for Representative Concentration Pathway (RCP) 2.6 and 850 m (±390 m) for RCP8.5. Even under the most optimistic scenario, glaciers may continue shrinking considerably, assuming a close relation between FLH and glacier extents. Under the most pessimistic scenario, glaciers may only remain at the highest summits above approximately 5800 m asl.

New land in the Neotropics: a review of biotic community, ecosystem, and landscape transformations in the face of climate and glacier change

Abstract: The high tropical Andes are rapidly changing due to climate change, leading to strong biotic community, ecosystem, and landscape transformations. While a wealth of glacier, water resource, and ecosystem-related research exists, an integrated perspective on the drivers and processes of glacier, landscape, and biota dynamics is currently missing. Here, we address this gap by presenting an interdisciplinary review that analyzes past, current, and potential future evidence on climate and glacier driven changes in landscape, ecosystem and biota at different spatial scales. We first review documented glacier changes and landscape evolution over past decades to millennia and analyze projected future glacier shrinkage until 2100 for two case studies in the tropical Andes. The effects of climate and glacier change on high Andean biota are then examined from paleoecological research and comparative gradient analyses to chronosequence and diachronic studies of vegetation dynamics. Our analysis indicates major twenty-first century landscape transformations with important socioecological implications which can be grouped into (i) formation of new lakes and drying of existing lakes as glaciers recede, (ii) alteration of hydrological dynamics in glacier-fed streams and high Andean wetlands, resulting in community composition changes, (iii) upward shifts of species and formation of new communities in deglaciated forefronts,(iv) potential loss of wetland ecosystems, and (v) eventual loss of alpine biota. We advocate strengthening an interdisciplinary research agenda with a strong policy formulation link that enables enhanced cross-sectorial cooperation and knowledge sharing, capacity building of relevant stakeholders, and a more active participation of both government agencies and social organizations.