Our projections highlight the almost complete disappearance of all glaciers outside the Mont-Blanc and Pelvoux (Ecrins region) massifs under RCP 4.5 (Fig. Our synthetic experiment does not account for glacier surface area shrinking either, which might have an impact on the glacier-wide MB signal. Both machine learning MB models were trained with exactly the same data coming from the 1048 annual glacier-wide MB values, and both were cross-validated using LSYGO. "The Patagonia Icefields are dominated by so-called 'calving' glaciers," Rignot said. volume13, Articlenumber:409 (2022) Alluvial landscape response to climate change in glacial rivers and the implications to transportation infrastructure. Reanalysis of 47 Years of Climate in the French Alps (19582005): Climatology and Trends for Snow Cover. Sci. 65, 453467 (2019). Conf. In fact, in many cases the surface lowering into warmer air causes this impact on the MB to be negative, further enhancing extreme negative mass balance rates. 3a). Our results serve as a strong reminder that the outcomes of existing large-scale glacier simulations should be interpreted with care, and that newly available techniques (such as the nonlinear deep learning approach presented here) and observations (e.g. Rainier is considered by the USGS to be one of the most threatening volcanoes in the Cascade Mountains. Our results also highlight the important role played by glacier geometry adjustment under changing climatic conditions, which is typical of mountain glaciers38. Analyses were made of the annual photographs . Google Scholar. (b) Climate predictors are based on climatic anomalies computed at the glaciers mean altitude with respect to the 19672015 reference period mean values. Maussion, F. et al. "Seeing the rapid and devastating collapse of this incredible and critical salmon in the Nisqually River is heartbreaking," said Troutt. Winter tourism under climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation. Res. Evol. Immerzeel, W. W. et al. We further assessed the effect of MB nonlinearities by comparing our simulated glacier changes with those obtained from other glacier evolution studies from the literature, which rely on temperature-index models for MB modelling. Alternatively, the comparisons against an independent large-scale glacier evolution model were less straightforward to achieve. Paul, F. et al. This is not the case for the nonlinear deep learning MB model, which captures the nonlinear response of melt and MB to increasing air temperatures, thus reducing the MB sensitivity to extreme positive and negative air temperature and summer snowfall anomalies (Fig. 2a and S3). Changes in DDFs with respect to air temperature also strongly depend on albedo, with ice presenting a substantially more nonlinear response than snow. These are among the cascading effects linked to glacier loss which impact ecosystems and . Between 1857 and 1979, Nisqually Glacier receded a total of 1,945 meters and advanced a total of 294 meters. At present, using complex surface energy balance models for large-scale glacier projections is not feasible yet, mainly due to the lack of input data. Particularly in Asia, water demand exceeds supply due to rapid population growth, with glacier . Earths Future https://doi.org/10.1029/2019EF001470 (2020). Since these flatter glaciers are more likely to go through extreme negative MB rates, nonlinear responses to future warming play a more important role, producing cumulative MB differences of up to 20% by the end of the century (Fig. Seasonal Arctic sea ice forecasting with probabilistic deep learning, Global glacier mass changes and their contributions to sea-level rise from 1961 to 2016, Two decades of glacier mass loss along the Andes, Centennial response of Greenlands three largest outlet glaciers, Accelerated global glacier mass loss in the early twenty-first century, High Mountain Asian glacier response to climate revealed by multi-temporal satellite observations since the 1960s, Rapid glacier retreat and downwasting throughout the European Alps in the early 21st century, Ice velocity and thickness of the worlds glaciers, Constraining glacier elevation and mass changes in South America, https://meetingorganizer.copernicus.org/EGU2020/EGU2020-20908.html, https://doi.org/10.5194/egusphere-egu2020-20908, https://doi.org/10.18750/MASSBALANCE.2019.R2019, https://doi.org/10.1016/B978-0-12-821575-3.00009-8, https://doi.org/10.1038/s41561-021-00885-z, http://creativecommons.org/licenses/by/4.0/, Unabated wastage of the Muz Taw Glacier in the Sawir Mountains during 19592021. Uncertainties of existing projections of future glacier evolution are particularly large for the second half of the 21st century due to a large uncertainty on future climatic conditions. Earth Syst. The new research suggests that the world's glaciers are disappearing more quickly than scientists previously estimated, and they . Cauvy-Frauni, S. & Dangles, O. H.Z. Climate Change 2013: The Physical Science Basis. Park, and S. Beason. Nat. Studies have warned about the use of temperature-index models for snow and ice projections under climate change for decades34,35,36. Model Dev. 22, 21462160 (2009). Mt. A global synthesis of biodiversity responses to glacier retreat. S7). Glaciers are large-scale, highly sensitive climate instruments which, ideally, should be picked up and weighed once a year. Res. The maximum advance of Nisqually Glacier in the last thousand years was located, and retreat from this point is believed to have started about 1840. MB rates only begin to approach equilibrium towards the end of the century under RCP 2.6, for which glaciers could potentially stabilize with the climate in the first decades of the 22nd century depending on their response time (Fig. By monitoring the change in size of glaciers around the world, scientists can learn about global climate change. 4e and 5). & Galiez, C. A deep learning reconstruction of mass balance series for all glaciers in the French Alps: 19672015. Simulations for projections in this study were made by generating an ensemble of 60 cross-validated models based on LSYGO. 1 and S1). For intermediate and pessimistic climate scenarios, no significant differences were found (Fig. This enables the recalculation of every topographical predictor used for the MB model, thus updating the mean glacier altitude at which climate data for each glacier are retrieved. Activity 13.3 Nisqually Glacier Response to Climate Change Course/Section Date: Name: Nisqually Glacier is a mountain glacier located on the south side of Mt. In Climate Change 157176 (Elsevier, 2021). Scand. Huss, M., Funk, M. & Ohmura, A. This has the strongest impact under RCP 2.6, where positive MB rates are more frequent (Fig. Model Dev. A dataset of 32 glaciers with direct annual glacier-wide MB observations and remote sensing estimates was used to train the models. The Cryosphere 13, 13251347 (2019). Toward mountains without permanent snow and ice: mountains without permanent snow and ice. melt and sublimation of ice, firn and snow; or calving)9; and (2) ice flow dynamics, characterized by the downward movement of ice due to the effects of gravity in the form of deformation of ice and basal sliding. Our results show that the mean elevation is far more variable than the kinematic ELA ( Fig. Ice caps in the Canadian Arctic, the Russian Arctic, Svalbard, and parts of the periphery of Greenland are major reservoirs of ice, as well as some of the biggest expected contributors to sea level rise outside the two polar ice sheets7. Nonlinear sensitivity of glacier mass balance to future climate change unveiled by deep learning. In order to investigate the effects of MB nonlinearities on flatter glaciers, we conducted a synthetic experiment using the French Alps dataset. Huss, M., Jouvet, G., Farinotti, D. & Bauder, A. & Funk, M. A comparison of empirical and physically based glacier surface melt models for long-term simulations of glacier response. Glaciers are important for agriculture, hydropower, recreation, tourism, and biological communities. Peer reviewer reports are available. 1gi)26 and glaciers shrinking to higher elevations where precipitation rates are higher as a result of orographic precipitation enhancement27. Multiple copies of this dataset were created, and for each individual copy a single predictor (i.e. Internet Explorer). Under warmer conditions (RCP 8.5), the differences between the linear and nonlinear MB model become smaller, as the topographical feedback from glacier retreat compensates for an important fraction of the losses induced by the late century warmer climate (Fig. 4a, b) and negative (Fig. The scheme simulates the mass balance as well as changes of the areal . Years in white in c-e indicate the disappearance of all glaciers in a given massif. 58, 267288 (1996). A NASA-led, international study finds Asia's high mountain glaciers are flowing more slowly in response to widespread ice loss, affecting freshwater availability downstream in India, Pakistan and China. 51, 573587 (2005). As for the MB modelling approach, a detailed explanation on this method can be found in a previous dedicated paper on the methods31. MathSciNet Alternatively, flatter glaciers (i.e. The dataset of initial glacier ice thickness, available for the year 2003, determines the starting point of our simulations. S4). 3). a1 throughout the whole century under RCP 4.5, with glacier retreat to higher elevations (positive effect on MB) compensating for the warmer climate (negative effect on MB). on various mass balance and radiation components) are opening the door for updated and better constrained projections. ALPGM uses a feed-forward fully connected multilayer perceptron, with an architecture (40-20-10-5-1) with Leaky-ReLu44 activation functions and a single linear function at the output. Rackauckas, C. et al. contributed to the climate analyses. 31, n/an/a (2004). Secure .gov websites use HTTPS A lock ( ) or https:// means you've safely connected to the .gov website. 5). Alpine glaciers, like this one near Mt. In summary, the linear approximations used by the Lasso manage to correctly fit the main cluster of average values but perform poorly for extreme values31. The two recent iterations of the Glacier Model Intercomparison Project (GlacierMIP7,8) have proved a remarkable effort to aggregate, compare and understand global glacier evolution estimates and their associated uncertainties. Gabbi, J., Carenzo, M., Pellicciotti, F., Bauder, A. Moreover these three aspects of glacier behavior are inextricably interwoven: a high sensitivity to climate change goes hand-in-hand with a large natural variability. Average cumulative MB projections of French Alpine glaciers with a nonlinear deep learning vs. a linear Lasso model for 29 climate scenarios; a with topographical feedback (allowing for glacier retreat) and e without topographical feedback (synthetic experiment with constant mean glacier altitude). ADS Loss of glaciers contributes to sea-level rise, creates environmental hazards and can alter aquatic habitats. Front. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (2018). In many aspects, it might be too optimistic, as many ice caps will have a negative impact on MB through thinning, bringing their mean surface elevation to lower altitudes, thus further warming their perceived climate. J. Hydrol. Glacier surface mass changes are commonly modelled by relying on empirical linear relationships between PDDs and snow, firn or ice melt8,9,10,29. Huss, M. et al. Nat Commun 13, 409 (2022). CPDD, winter snowfall or summer snowfall) was modified for all glaciers and years. Ecol. Through these surveys "bulges" have been tracked as they travel down the glacier (c). In the past, shortwave radiation represented a more important fraction in the glacier surface energy budget than the energy fluxes directly related to air temperature (e.g. To interactively describe to response of glaciers to climate change, a glacier parameterization scheme has been developed and implemented into the regional climate model REMO. This removes the topographical feedback typical from mountain glaciers, and reproduces the more extreme climate conditions that ice caps are likely to endure through the 21st century40. Deep artificial neural networks (ANNs) are nonlinear models that offer an alternative approach to these classic methods. ice cap-like behaviour). Cite this article. If material is not included in the articles Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. Due to the statistical nature of the Lasso model, the response to snowfall anomalies is also highly influenced by variations in PDDs (Fig. 2015 IEEE Int. This will reduce the importance of shortwave radiation for future ablation rates, and it is expected to result in a reduction in values of degree-day factors (DDFs) and therefore a significant change in melt sensitivity to air temperature variations36. Roberts, D. R. et al. Therefore, their sensitivities to the projected 21st century increase in PDDs are linear. Therefore, we were capable of isolating the different behaviours of the nonlinear deep learning model and a linear machine learning model based on the Lasso30. The maximum downvalley position of the glacier is marked by either a 4e). Res. Hugonnet, R. et al. We also use this method to extract glacier borderlines from satellite images across the western Lenglongling mountains. S5b). However, the impact of different climate configurations, such as a more continental and drier climate or a more oceanic and humid climate, would certainly have an impact on the results, albeit a much less important one than the lack of topographical feedback explored here. Future high-mountain hydrology: a new parameterization of glacier retreat. ICCV (2015) https://doi.org/10.1109/iccv.2015.123. Simulations were then performed by averaging the outputs of each one of the 60 ensemble members. This results in a higher complexity of the Lasso compared to a temperature-index model. By Carol Rasmussen,NASA's Earth Science News Team. Differences for individual glaciers can be much more pronounced, as large and flat glaciers will have topoclimatic configurations that produce more extreme MB rates than small and steep glaciers with a short response time. how climate change and glacier retreat are reshaping whole aquatic ecosystems, there is a need to develop an integrated understanding spanning multiple taxonomic groups and trophic levels in glacier-fed rivers (e.g., bacteria, protists, fungi, algae, diatoms, invertebrates, mammals, amphibians, and fish; Clitherow et al. The source code of the glacier model can be freely accessed in the following repository: https://github.com/JordiBolibar/ALPGM. Therefore, an alternative nonlinear parameterization for the reduction in MB sensitivity under increasing air temperatures would be useful. This method has the advantage of including glacier-specific dynamics in the model, encompassing a wide range of different glacier behaviours. Spandre, P. et al. & Zumbhl, H. J. Greenland's melting glaciers, which plunge into Arctic waters via steep-sided inlets, or fjords, are among the main contributors to global sea level rise in response to climate change. Hydrol. A physically-based method for mapping glacial debris-cover thickness from ASTER satellite imagery: development and testing at Miage Glacier, Italian Alps Discovery - the University of Dundee Research Portal Recent efforts have been made to improve the representation of ice flow dynamics in these models, replacing empirical parametrizations with simplified physical models9,10. Photographs taken by Simo Rsnen (Bossons glacier, European Alps, CC BY-SA 3.0) and Doug Hardy (Quelccaya ice cap, Andes, CC BY-SA 4.0). Rev. Deep learning applied to glacier evolution modelling. This modelling approach was described in detail in a previous publication dedicated to the methods, where the ALpine Parameterized Glacier Model (ALPGM43) was presented31. S5 and S6). GloGEMflow has been previously applied in a study over the whole European Alps, and its temperature-index model was mainly calibrated with MB data from the Swiss Alps. Here, we perform the first-ever glacier evolution projections based on deep learning by modelling the 21st century glacier evolution in the French Alps. Atmospheres 121, 77107728 (2016). Annu. By 2100, under RCP 4.5, these two high-altitude massifs are predicted to retain on average 26% and 13% of their 2015 volume, respectively, with most of the ice concentrated in a few larger glaciers (>1km2, Fig. The estimated ice thickness for Mer de Glace (28.87km2 in 2015) was increased by 25% in order to correct the bias with respect to field observations31. Geophys. Hock, R. Temperature index melt modelling in mountain areas. Glaciers with the greatest degree of seasonality in their flow behavior, such as Nisqually and Shoestring glaciers, responded most rapidly.
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