Browsing by Autor "Mathias Vuille"

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A major advance of tropical Andean glaciers during the Antarctic cold reversal
(Nature Portfolio, 2014) Vincent Jomelli; Vincent Favier; Mathias Vuille; Régis Braucher; Léo Martin; Pierre‐Henri Blard; Christopher M. Colose; Daniel Brunstein; Feng He; Myriam Khodri
Climate variability during the last 1000 years inferred from Andean ice cores: A review of methodology and recent results
(Elsevier BV, 2008) Françoise Vimeux; Patrick Ginot; Margit Schwikowski; Mathias Vuille; Georg F. Hoffmann; Lonnie G. Thompson; U. Schotterer
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.
El Niño‐Southern Oscillation (ENSO) influence on a Sajama volcano glacier (Bolivia) from 1963 to 1998 as seen from Landsat data and aerial photography
(American Geophysical Union, 2001) Yves Arnaud; Frédéric Muller; Mathias Vuille; Pierre Ribstein
Sajama volcano, located in the Bolivian Altiplano, is the southernmost tropical glacier and, owing to its situation, approximately 100 km east of the Pacific coast, is well suited to study the El Niño‐Southern Oscillation phenomenon. Landsat data from 1972 to 1998 and a 1963 aerial photograph are used to monitor the snow line fluctuations on a selected part of Sajama volcano. We assume that a few months after the rainy season, the snow line is representative of the previous rainy season, if no recent snowfall has occurred. By observing precipitation from the stations surrounding Sajama volcano and by verifying snow presence on surrounding summits, we detect images with recent snowfall likely to disturb the climatic significance of the snow line. A snow line evolution model takes into account the different image acquisition dates and adjusts the snow line elevation accordingly for the middle of the dry season. A progressive rise of the snow line elevation is observed from 1963 to 1998 with a sustained rise from 1984 to 1990. The snow line altitude is related to the Southern Oscillation Index. Even after the high precipitation of the 1996–1997 wet season, the following El Niño 1997–1998 leads to a substantial rise of the snow line. The snow line elevation is related primarily to the total rainy season precipitation and to a lesser degree to the maximum monthly mean temperature of the warmest month, thus confirming a greater snow line sensitivity to precipitation than to temperature.
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
Review article of the current state of glaciers in the tropical Andes: a multi-century perspective on glacier evolution and climate change
(2012) 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 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 computed global average. 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 as a percentage, 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 showed that variability of the surface temperature of the Pacific Ocean is the main factor governing variability of the mass balance variability at the interannual to decadal time scale. 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.
Tropical climate change recorded by a glacier in the central Andes during the last decades of the twentieth century: Chacaltaya, Bolivia, 16°S
(American Geophysical Union, 2003) Bernard Francou; Mathias Vuille; Patrick Wagnon; Javier Mendoza; Jean‐Emmanuel Sicart
The reasons for the accelerated glacier retreat observed since the early 1980s in the tropical Andes are analyzed based on the well‐documented Chacaltaya glacier (Bolivia). Monthly mass balance measurements available over the entire 1991–2001 decade are interpreted in the light of a recent energy balance study performed on nearby Zongo glacier and further put into a larger‐scale context by analyzing the relationship with ocean‐atmosphere dynamics over the tropical Pacific‐South American domain. The strong interannual variability observed in the mass balance is mainly dependent on variations in ablation rates during the austral summer months, in particular during DJF. Since high humidity levels during the summer allow melting to be distinctly predominant over sublimation, net all‐wave radiation, via albedo and incoming long‐wave radiation, is the main factor that governs ablation. Albedo depends on snowfall and a deficit during the transition period and in the core of the wet season (DJF) maintains low albedo surfaces of bare ice, which in turn leads to enhanced absorption of solar radiation and thus to increased melt rates. On a larger spatial scale, interannual glacier evolution is predominantly controlled by sea surface temperature anomalies (SSTA) in the eastern equatorial Pacific (Niño 1+2 region). The glacier mass balance is influenced by tropical Pacific SSTA primarily through changes in precipitation, which is significantly reduced during El Niño events. The more frequent occurrence of El Niño events and changes in the characteristics of its evolution, combined with an increase of near‐surface temperature in the Andes, are identified as the main factors responsible for the accelerated retreat of Chacaltaya glacier.