Browsing by Autor "Antoine Rabatel"

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A Nonlinear Statistical Model for Extracting a Climatic Signal From Glacier Mass Balance Measurements
(Wiley, 2018) Christian Vincent; Álvaro Soruco; M Azam; Rubén Basantes-Serrano; Miriam Jackson; Bjarne Kjøllmoen; Emmanuel Thibert; Patrick Wagnon; Delphine Six; Antoine Rabatel
Abstract Understanding changes in glacier mass balances is essential for investigating climate changes. However, glacier‐wide mass balances determined from geodetic observations do not provide a relevant climatic signal as they depend on the dynamic response of the glaciers. In situ point mass balance measurements provide a direct signal but show a strong spatial variability that is difficult to assess from heterogeneous in situ measurements over several decades. To address this issue, we propose a nonlinear statistical model that takes into account the spatial and temporal changes in point mass balances. To test this model, we selected four glaciers in different climatic regimes (France, Bolivia, India, and Norway) for which detailed point annual mass balance measurements were available over a large elevation range. The model extracted a robust and consistent signal for each glacier. We obtained explained variances of 87.5, 90.2, 91.3, and 75.5% on Argentière, Zongo, Chhota Shigri, and Nigardsbreen glaciers, respectively. The standard deviations of the model residuals are close to measurement uncertainties. The model can also be used to detect measurement errors. Combined with geodetic data, this method can provide a consistent glacier‐wide annual mass balance series from a heterogeneous network. This model, available to the whole community, can be used to assess the impact of climate change in different regions of the world from long‐term mass balance series.
A Review of the Current State and Recent Changes of the Andean Cryosphere
(Frontiers Media, 2020) Mariano Masiokas; Antoine Rabatel; Andrés Rivera; Lucas Ruiz; Pierre Pitte; J. L. Ceballos; Gonzalo Barcaza; Álvaro Soruco; Francisca Bown; Étienne Berthier
The Andes Cordillera contains the most diverse cryosphere on Earth, including extensive areas covered by seasonal snow, numerous tropical and extratropical glaciers, and many mountain permafrost landforms. Here, we review some recent advances in the study of the main components of the cryosphere in the Andes, and discuss the changes observed in the seasonal snow and permanent ice masses of this region over the past decades. The open access and increasing availability of remote sensing products has produced a substantial improvement in our understanding of the current state and recent changes of the Andean cryosphere, allowing an unprecedented detail in their identification and monitoring at local and regional scales. Analyses of snow cover maps has allowed the identification of seasonal patterns and long term trends in snow accumulation for most of the Andes, with some sectors in central Chile and central-western Argentina showing a clear decline in snowfall and snow persistence since 2010. This recent shortage of mountain snow has caused an extended, severe drought that is unprecedented in the hydrological and climatological records from this region. Together with data from global glacier inventories, detailed inventories at local/regional scales are now also freely available, providing important new information for glaciological, hydrological and climatological assessments in different sectors of the Andes. Numerous studies largely based on field measurements and/or remote sensing techniques have documented the recent glacier shrinkage throughout the Andes. This observed ice mass loss has put Andean glaciers among the highest contributors to sea level rise per unit area. Other recent studies have focused on rock glaciers, showing that in extensive semi-arid sectors of the Andes these mountain permafrost features contain large reserves of freshwater and may play a crucial role as future climate becomes warmer and drier in this region. Many relevant issues remain to be investigated, however, including an improved estimation of ice volumes at local scales, and detailed assessments of the hydrological significance of the different components of the cryosphere in Andean river basins.
Can the snowline be used as an indicator of the equilibrium line and mass balance for glaciers in the outer tropics?
(Cambridge University Press, 2012) Antoine Rabatel; Ana Bermejo; Edwin Loarte; Álvaro Soruco; Jesús Gómez; Gonzalo Leonardini; Christian Vincent; Jean Emmanuel Sicart
Abstract Because the glacier snowline is easy to identify on optical satellite images and because in certain conditions it can be used as an indicator of the equilibrium line, it may be a relevant parameter for the study of the relationships between climate and glaciers. Although several studies have shown that the snowline altitude (SLA) at the end of the hydrological year is a good indicator of the equilibrium-line altitude (ELA) for mid-latitude glaciers, such a relationship remains conjectural for tropical glaciers. Indeed, unlike in mid-latitudes, tropical climate conditions result in a distinct seasonality of accumulation/ablation processes. We examine this relationship using direct field ELA and mass-balance measurements made on Glaciar Zongo, Bolivia (~16° S), vand Glaciar Artesonraju, Peru (~9° S), and the SLA retrieved from satellite images acquired in the past two decades. We show that on glaciers in the outer tropics: (1) ablation is reduced during the dry season in austral winter (May-August), the SLA does not change much, and satellite images acquired between May and August could be used to compute the SLA; and (2) the highest SLA detected on a number of satellite images acquired during the dry season provides a good estimate of the annual ELA. However, as snowfall events can occur during the dry season, the SLA detected on satellite images tends to underestimate the ELA. Thus, we recommend validating the SLA computed from satellite images with field data collected on a benchmark glacier before measuring the SLA on other glaciers in the same mountain range for which no field data are available. This study is a major step towards extending the measurement of glacier parameters (ELA and mass balance) at the scale of a whole mountain range in the outer tropics to better document the relationships between climate and glaciers.
Climate Controls on the Interseasonal and Interannual Variability of the Surface Mass and Energy Balances of a Tropical Glacier (Zongo Glacier, Bolivia, 16°S): New Insights From the Multi‐Year Application of a Distributed Energy Balance Model
(Wiley, 2022) Philémon Autin; Jean‐Emmanuel Sicart; Antoine Rabatel; Álvaro Soruco; Regine Hock
Abstract The application of a distributed energy balance model over nine years at an hourly time step to a 20 × 20 m grid cell over Glacier Zongo (Bolivia, 16°S) enabled assessment of the climate factors that control the interseasonal and interannual variability of its surface mass balance. The model was validated by comparing the measured and simulated discharge at the outlet, albedo at the Automatic Weather Station, surface state and annual mass balance both glacier‐wide and as a function of altitude. Analysis of the mean monthly energy fluxes highlighted the importance of the meteorological conditions over October and November on the variability of the annual surface mass balance. Two sensitivity analyses are presented, one of the distribution of precipitation over time which maintains a physical coherence between the different meteorological variables and one of the impact of prolonged periods of intense cloud radiative forcing on the surface mass balance. The distribution of precipitation events over time and their associated amounts are the main drivers of the interannual variability of the surface mass balance via an albedo feedback effect. Additionally, prolonged periods of negative cloud radiative forcing, specifically over the month of November, notably reduce the melt rate.
Climate controls on the interseasonal and interannual variability of the surface mass balance of a tropical glacier (Zongo Glacier, Bolivia, 16&deg;S): new insights from the application of a distributed energy balance model over 9 years
(2021) Philémon Autin; Jean Emmanuel Sicart; Antoine Rabatel; Álvaro Soruco
Earth and Space Science Open Archive This preprint has been submitted to and is under consideration at Journal of Geophysical Research - Atmospheres. ESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary.Learn more about preprints preprintOpen AccessYou are viewing the latest version by default [v1]Climate controls on the interseasonal and interannual variability of the surface mass balance of a tropical glacier (Zongo Glacier, Bolivia, 16°S): new insights from the application of a distributed energy balance model over 9 yearsAuthorsPhilémonAutiniDJean EmmanuelSicartAntoineRabateliDAlvaroSorucoSee all authors Philémon AutiniDCorresponding Author• Submitting AuthorUniversité Grenoble AlpesiDhttps://orcid.org/0000-0002-5830-1629view email addressThe email was not providedcopy email addressJean Emmanuel SicartIRD /LTHE UMR 5564view email addressThe email was not providedcopy email addressAntoine RabateliDUniv. Grenoble AlpesiDhttps://orcid.org/0000-0002-5304-1055view email addressThe email was not providedcopy email addressAlvaro SorucoUniversidad Mayor de San Andrésview email addressThe email was not providedcopy email address
Comment on tc-2022-70
(2022) RubÃ©n Basantes-Serrano; Antoine Rabatel; Bernard Francou; Christian Vincent; Álvaro Soruco; Thomas Condom; Jean Carlo RuÃz
Abstract. We present a comprehensive study of the evolution of the glaciers on the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on geodetic observations of aerial photographs and high-resolution satellite images, we explore the effects of morpho-topographic and climate variables on glacier volumes. Contrasting behaviour was observed over the whole period, with two periods of strong mass loss, 1956–1964 (−0.72 m w.e. yr−1) and 1979–1997 (−0.82 m w.e. yr−1), and two periods with slight mass loss, 1965–1978 (0.10 m w.e. yr−1) and 1998–2016 (−0.26 m w.e. yr−1). There was a 42 % reduction in the total surface area of the ice cap. Individually, glacier responses were modulated by morpho-topographic variables (e.g. maximum and median altitude and surface area), particularly in the case of the small tongues located at low elevations (Glacier 1, 5 and 16) which have been undergoing accelerated disintegration since the 1990s and will likely disappear in the coming years. Moreover, thanks to the availability of aerial data, a surging event was detected on the Antisana Glacier 8 (G8) in the 2009–2011 period; such an event is extremely rare in this region and deserves a dedicated study. Despite the effect of the complex topography, glaciers have reacted in agreement with changes in climate forcing, with a stepwise transition towards warmer and alternating wet–dry conditions since the mid-1970s. Long-term decadal variability is consistent with the warm–cold conditions observed in the Pacific Ocean represented by the Southern Oscillation index.
Comment on tc-2022-70
(2022) Rubén Basantes-Serrano; Antoine Rabatel; Bernard Francou; Christian Vincent; Álvaro Soruco; Thomas Condom; Jean Carlo RuÃz
We present a comprehensive study of the evolution of the glaciers in the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on geodetic observations of aerial photographs and high-resolution satellite images, we explore the effects of morpho-topographic and climate variables on glacier volumes. Contrasting behavior was observed over the whole period, with two periods of strong mass loss: 1956–1964 and 1979–1997, and two periods with slight mass loss: 1965–1978 and 1997–2016. There was a 42 % reduction in the total surface area of the ice cap. Individually, glacier responses were modulated by morpho-topographic variables (e.g., maximum and median altitude, and surface area), particularly in the case of the small tongues located at low elevations (Glacier 1, 5, and 16) which have been undergoing accelerated disintegration since the 1990s, and will likely disappear in the coming years. Moreover, thanks to the availability of aerial data, a surging event was detected in the Antisana G8 in the 2009–2011 period; such an event is extremely rare in this region and deserves a dedicated study. Despite the effect of the complex topography, glaciers react in agreement with changes in climate forcing, with a stepwise transition towards warmer and alternating wet/dry conditions since the mid-1970s. Long-term decadal variability is consistent with the warm/cold conditions observed in the Pacific Ocean represented by the Southern Oscillation Index.
COMPARACIÓN DE MÉTODOS PARA ESTIMAR EL BALANCE DE MASA DEL GLACIAR DE ZONGO, BOLIVIA (16º S, 68º O)
(Universidad Nacional de La Plata, 2014) Álvaro Soruco; Christian Vincent; Bernard Francou; Antoine Rabatel
La serie más larga y continua de mediciones de balance de masa en la Zona Intertropical de Sud América corresponden al glaciar de Zongo, Bolivia. Las mediciones fueron iniciadas en 1991, empleando tanto el método glaciológico como el hidrológico. Los resultados muestran discrepancias en los balances de masa obtenidos por ambos métodos. Con el objetivo de verificar estos balances de masa, se realizó un nuevo balance de masa mediante el método fotogramétrico, que fue comparado con los métodos glaciológico e hidrológico ya existentes. Los resultados de esta comparación entre balances de masa obtenidos con el método hidrológico y fotogramétrico son equivalentes, mientras que la comparación de los resultados obtenidos entre estos y el método glaciológico, están en desacuerdo. Esta diferencia, se atribuye a la imposibilidad de realizar mediciones adecuadas con el método glaciológico en las zonas de difícil acceso del glaciar de Zongo, las cuales son simplemente interpoladas en la estimación del balance de masa neto específico. Los resultados muestran, en general, que el glaciar Zongo ha estado muy cercano a un estadio de equilibrio entre 1956 y 1963; ganó masa entre 1963 y 1975 de manera significativa (3.86 m eq. agua) y a partir de 1975, los balances de masa son negativos. Por otra parte, se han extendido las observaciones del balance de masa del glaciar de Zongo para los últimos 50 años (1956-2006).
Contribution of glacier runoff to water resources of La Paz city, Bolivia (16° S)
(Cambridge University Press, 2015) Álvaro Soruco; Christian Vincent; Antoine Rabatel; Bernard Francou; Emmanuel Thibert; Jean Emmanuel Sicart; Thomas Condom
Abstract The supply of glacier water to La Paz city, Bolivia, between 1963 and 2006 was assessed at annual and seasonal timescales based on the mass-balance quantification of 70 glaciers located within the drainage basins of La Paz. Glaciers contributed ∼15% of water resources at an annual scale (14% in the wet season, 27% in the dry season). Uncertainties in our estimation are related to the assumed constant precipitation (∼0.5% for ice-free areas and up to 6.5% for glaciated areas), the constant runoff coefficient (∼1%), the surface areas of the glaciers and catchments (∼5%) and the mean mass-balance uncertainty of the 21 glaciers used to obtain the mass balance of the 70 glaciers (12% of the total discharge). Despite the loss of 50% of the glacierized area during the study period, runoff at La Paz did not change significantly, showing that increase in ice melt rates compensated for reduction in the surface area of the glaciers. In the future, assuming complete disappearance of the glaciers and no change in precipitation, runoff should diminish by ∼12% at an annual scale, 9% during the wet season and 24% during the dry season.
Current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change
(Copernicus Publications, 2013) Antoine Rabatel; Bernard Francou; Álvaro Soruco; Jesús Gómez; Bolívar Cáceres; J. L. Ceballos; Rubén Basantes-Serrano; Mathias Vuille; Jean‐Emmanuel Sicart; Christian Huggel
Abstract. The aim of this paper is to provide the community with a comprehensive overview of the studies of glaciers in the tropical Andes conducted in recent decades leading to the current status of the glaciers in the context of climate change. In terms of changes in surface area and length, we show that the glacier retreat in the tropical Andes over the last three decades is unprecedented since the maximum extension of the Little Ice Age (LIA, mid-17th–early 18th century). In terms of changes in mass balance, although there have been some sporadic gains on several glaciers, we show that the trend has been quite negative over the past 50 yr, with a mean mass balance deficit for glaciers in the tropical Andes that is slightly more negative than the one computed on a global scale. A break point in the trend appeared in the late 1970s with mean annual mass balance per year decreasing from −0.2 m w.e. in the period 1964–1975 to −0.76 m w.e. in the period 1976–2010. In addition, even if glaciers are currently retreating everywhere in the tropical Andes, it should be noted that this is much more pronounced on small glaciers at low altitudes that do not have a permanent accumulation zone, and which could disappear in the coming years/decades. Monthly mass balance measurements performed in Bolivia, Ecuador and Colombia show that variability of the surface temperature of the Pacific Ocean is the main factor governing variability of the mass balance at the decadal timescale. Precipitation did not display a significant trend in the tropical Andes in the 20th century, and consequently cannot explain the glacier recession. On the other hand, temperature increased at a significant rate of 0.10 °C decade−1 in the last 70 yr. The higher frequency of El Niño events and changes in its spatial and temporal occurrence since the late 1970s together with a warming troposphere over the tropical Andes may thus explain much of the recent dramatic shrinkage of glaciers in this part of the world.
Ecosystem sentinels for climate change? Evidence of wetland cover changes over the last 30 years in the tropical Andes
(Public Library of Science, 2017) Olivier Dangles; Antoine Rabatel; Martin J. Kraemer; Gabriel Zeballos; Álvaro Soruco; Dean Jacobsen; Fabien Anthelme
While the impacts of climate change on individual species and communities have been well documented there is little evidence on climate-mediated changes for entire ecosystems. Pristine alpine environments can provide unique insights into natural, physical and ecological response to climate change yet broad scale and long-term studies on these potential 'ecosystem sentinels' are scarce. We addressed this issue by examining cover changes of 1689 high-elevation wetlands (temporarily or perennial water-saturated grounds) in the Bolivian Cordillera Real, a region that has experienced significant warming and glacier melting over the last 30 years. We combined high spatial resolution satellite images from PLEIADES with the long-term images archive from LANDSAT to 1) examine environmental factors (e.g., glacier cover, wetland and watershed size) that affected wetland cover changes, and 2) identify wetlands' features that affect their vulnerability (using habitat drying as a proxy) in the face of climate change. Over the (1984-2011) period, our data showed an increasing trend in the mean wetland total area and number, mainly related to the appearance of wet grassland patches during the wetter years. Wetland cover also showed high inter-annual variability and their area for a given year was positively correlated to precipitation intensities in the three months prior to the image date. Also, round wetlands located in highly glacierized catchments were less prone to drying, while relatively small wetlands with irregularly shaped contours suffered the highest rates of drying over the last three decades. High Andean wetlands can therefore be considered as ecosystem sentinels for climate change, as they seem sensitive to glacier melting. Beyond the specific focus of this study, our work illustrates how satellite-based monitoring of ecosystem sentinels can help filling the lack of information on the ecological consequences of current and changing climate conditions, a common and crucial issue especially in less-developed countries.
Facilitation vs. competition: divergent plant-plant interactions in tropical and temperate postglacial ecosystems
(2025) Lucie Bivaud; Anaïs Zimmer; Guillaume Papuga; Tristan Charles‐Dominique; Álex Aguilar; Rosa Isela Meneses; Antoine Rabatel; Jean Salcedo Aliaga; Sophie Vallée; Álvaro Soruco
Global glacier retreat is rapidly exposing vast terrains of bare ground, leading to the emergence of postglacial ecosystems. The success of this emergence will determine the future of a substantial fraction of alpine biodiversity and associated ecosys
Glacier mass balance determination by remote sensing in the French Alps: progress and limitation for time series monitoring
(2004) J.-P. Dedieu; Antoine Rabatel; Christian Vincent; François Valla; Emmanuel Thibert; Yves Arnaud
This paper presents an approach founded on an indirect methodology to determine the distribution of mass balance at high spatial resolution using remote sensing and ground stakes measurements. A recent time series of images from optical and SAR data are selected on 3 outlet glaciers well suited in the French Alps to evaluate the accuracy of the computed mass balance. The method is based on the snowline determination as a proxy of the equilibrium line altitude (ELA). The key of the transfer is the activity coefficient (db/dz) for the annual mass balance calculation. Comparison between measured and computed mass balance provide a good correspondence (R/sup 2/=0.90) and allows extending the method on large-scale areas. The limitations are cloudiness for optical data and high slope distortion on SAR images.
Glacier mass balance reconstruction by remote sensing in the French alps : comparison with ground measurements
(2004) J.-P. Dedieu; Antoine Rabatel; Christian Vincent; Álvaro Soruco
The Alpine glaciers are sensitive to climate fluctuation, and glacier mass balance may be used as a proxy indicator of the regional climate change impacts. An indirect methodology is presented for determining the distribution of mass balance at high spatial resolution using remote sensing and ground stakes measurements. The method is based on the snowline determination as a proxy of the equilibrium line altitude (ELA) and the key of the transfer is the activity coefficient (db/dz) for the annual mass balance calculation. Three outlet glaciers well suited in the French Alps (ground stakes) were selected to evaluate the accuracy of the method for a short period (7 cycles) and extended for a longest period (15 cycles) for a glacier with limited ground measurements. The computed distribution of mass-balance compares well (R/sup 2/ = 0.90) with mass-balance measurements made at stakes installed along the glacier centre line for the short period.
Glacier recession on Cerro Charquini (16° S), Bolivia, since the maximum of the Little Ice Age (17th century)
(Cambridge University Press, 2006) Antoine Rabatel; Abraham Machaca; Bernard Francou; Vincent Jomelli
Abstract Cerro Charquini, Bolivia (Cordillera Real, 5392 ma.s.l.) was selected as a site to reconstruct glacier recession since the maximum of the Little Ice Age (LIA) in the central Andes. Five glaciers, located on differently exposed slopes, present comprehensive and well-preserved morainic systems attributed to former centuries. The moraines were dated by lichenometry and show a consistent organization on the different slopes. The past geometry of the glaciers was reconstructed using ground topography and aerophotogrammetry. Lichenometric dating shows that the LIA maximum occurred in the second half of the 17th century, after which the glaciers have receded nearly continuously. Over the last decades of the 20th century (1983–97), recession rates increased by a factor of four. On the northern and western slopes, glaciers receded more than on the southern and eastern slopes (by 78% and 65% of their LIA maximum area, respectively). The mean equilibrium-line altitude (ELA) rose by about 160 m between the LIA maximum and 1997. Recession rates were analysed in terms of climatic signal, suggesting that glacier recession since the LIA maximum was mainly due to a change in precipitation and that the 19th century may have been drier. For the 20th century, a temperature rise of about 0.6°C appears to be the main cause of glacier recession. Recent climatic conditions from 1983 to 1997 correspond to a mass deficit of about 1.36m w.e.a –1 . If such conditions persist, the small glaciers below 5300ma.s.l. in the Cordillera Real should disappear completely in the near future.
Mass balance and area changes of glaciers in the Cordillera Real and Tres Cruces, Bolivia, between 2000 and 2016
(Cambridge University Press, 2019) Thorsten Seehaus; Philipp Malz; Christian Sommer; Álvaro Soruco; Antoine Rabatel; Matthias Braun
Abstract Climate change has led to a significant shrinkage of glaciers in the Tropical Andes during the last decades. Recent multi-temporal quantifications of ice mass loss at mountain range to regional scale are missing. However, this is fundamental information for future water resource planning and glacier change projections. In this study, we measure temporally consistent glacier area changes and geodetic mass balances throughout the Bolivian Cordillera Real and Tres Cruces based on multi-sensor remote-sensing data. By analyzing multi-spectral satellite images and interferometric SAR data, a glacier recession of 81 ± 18 km 2 (29%; 5.1 ± 1.1 km 2 a −1 ), a geodetic mass balance of −403 ± 78 kg m −2 a −1 and a total ice mass loss of 1.8 ± 0.5 Gt is derived for 2000–2016. In the period 2013–2016, ice mass loss was 21% above the average rate. A retreat rate of 15 ± 5 km 2 a −1 and a mass budget of −487 ± 349 kg m −2 a −1 are found in this more recent period. These higher change rates can be attributed to the strong El Niño event in 2015/16. The analyses of individual glacier changes and topographic variables confirmed the dependency of the mass budget and glacier recession on glacier aspect and median elevation.
Mass balance estimation on the Zongo glacier, Bolivia, using a semi-distributedconceptual model (SCM)
(Copernicus Publications, 2026) Gabriela Quispe; Carlos Cárdenas; Pablo Fuchs; Alvaro Soruco; Antoine Rabatel
Abstract. The mass balance of a glacier is used to quantify the accumulation and melting processes, which affect its mass. With this information, it is possible to infer the variation in water reserves, which will support decision-making based on the supply and demand of water. The objective of this work is to show the results of a mass balance model applied to the Zongo Glacier in Bolivia. The model used is a semi-distributed conceptual model (Schaefli et al., 2005). The monthly sensitivity of the mass balance and discharge predictions was evaluated for the hydrological years 2004-2006. Our results show that the model presents discharge and mass balance values with an MAE error of 2.4 and a BIAS of 1.3 concerning the data observed in the glacier. Simple conceptual models can be a valuable tool to project the behavior of a glacial basin, but only if it has sufficient information for the calibration and validation of the model parameters.
New insights into the decadal variability in glacier volume of a tropical ice cap, Antisana (0°29′ S, 78°09′ W), explained by the morpho-topographic and climatic context
(Copernicus Publications, 2022) Rubén Basantes-Serrano; Antoine Rabatel; Bernard Francou; Christian Vincent; Álvaro Soruco; Thomas Condom; Jean Carlo Ruíz
Abstract. We present a comprehensive study of the evolution of the glaciers on the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on geodetic observations of aerial photographs and high-resolution satellite images, we explore the effects of morpho-topographic and climate variables on glacier volumes. Contrasting behaviour was observed over the whole period, with two periods of strong mass loss, 1956–1964 (−0.72 m w.e. yr−1) and 1979–1997 (−0.82 m w.e. yr−1), and two periods with slight mass loss, 1965–1978 (0.10 m w.e. yr−1) and 1998–2016 (−0.26 m w.e. yr−1). There was a 42 % reduction in the total surface area of the ice cap. Individually, glacier responses were modulated by morpho-topographic variables (e.g. maximum and median altitude and surface area), particularly in the case of the small tongues located at low elevations (Glacier 1, 5 and 16) which have been undergoing accelerated disintegration since the 1990s and will likely disappear in the coming years. Moreover, thanks to the availability of aerial data, a surging event was detected on the Antisana Glacier 8 (G8) in the 2009–2011 period; such an event is extremely rare in this region and deserves a dedicated study. Despite the effect of the complex topography, glaciers have reacted in agreement with changes in climate forcing, with a stepwise transition towards warmer and alternating wet–dry conditions since the mid-1970s. Long-term decadal variability is consistent with the warm–cold conditions observed in the Pacific Ocean represented by the Southern Oscillation index.
New insights into the decadal variability in glacier volume of an iconic tropical ice-cap explained by the morpho-climatic context, Antisana, (0°29’ S, 78°09’ W)
(2022) Rubén Basantes-Serrano; Antoine Rabatel; Bernard Francou; Christian Vincent; Álvaro Soruco; Thomas Condom; Jean Carlo Ruíz
Abstract. We present a comprehensive study of the evolution of the glaciers in the Antisana ice cap (tropical Andes) over the period 1956–2016. Based on geodetic observations of aerial photographs and high-resolution satellite images, we explore the effects of morpho-topographic and climate variables on glacier volumes. Contrasting behavior was observed over the whole period, with two periods of strong mass loss: 1956–1964 and 1979–1997, and two periods with slight mass loss: 1965–1978 and 1997–2016. There was a 42 % reduction in the total surface area of the ice cap. Individually, glacier responses were modulated by morpho-topographic variables (e.g., maximum and median altitude, and surface area), particularly in the case of the small tongues located at low elevations (Glacier 1, 5, and 16) which have been undergoing accelerated disintegration since the 1990s, and will likely disappear in the coming years. Moreover, thanks to the availability of aerial data, a surging event was detected in the Antisana G8 in the 2009–2011 period; such an event is extremely rare in this region and deserves a dedicated study. Despite the effect of the complex topography, glaciers react in agreement with changes in climate forcing, with a stepwise transition towards warmer and alternating wet/dry conditions since the mid-1970s. Long-term decadal variability is consistent with the warm/cold conditions observed in the Pacific Ocean represented by the Southern Oscillation Index.
Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead
(Elsevier BV, 2017) Mathias Vuille; Mark Carey; Christian Huggel; Wouter Buytaert; Antoine Rabatel; Dean Jacobsen; Álvaro Soruco; Marcos Villacís; Christian Yarlequé; O. Elison Timm