Res. In recent years, shrinking glaciers have contributed to about 30% of global sea level rise 1. This rapid glacier retreat is already having an environmental impact on natural hazards20, mountain ecosystems21, and biodiversity6. Nisqually Glacier in Mount Rainier National Park, Wash., covers 2.5 square miles (6.5 square kilometers) (1961) and extends from an altitude of about 14,300 feet (4,400 meters) near the top of Mount Rainier down to 4,700 feet (1,400 meters), in a horizontal distance of 4.1 miles (6.6 kilometers). Google Scholar. Secure .gov websites use HTTPS A lock ( ) or https:// means you've safely connected to the .gov website. 4 vs.S5). Earth Sci. 4a, b) and negative (Fig. Reanalysis of 47 Years of Climate in the French Alps (19582005): Climatology and Trends for Snow Cover. A similar behaviour is observed when comparing temperature-index models to more complex models (e.g. 3c). When working with spatiotemporal data, it is imperative to respect spatial and temporal data structures during cross-validation in order to correctly assess an accurate model performance48. Climate Change Indicators: Glaciers | US EPA Climate change spells disaster for the world's glaciers : NPR . acknowledges the funding received from a EU Horizon 2020 Marie Skodowska-Curie Individual Fellowship (grant no. ISSN 2041-1723 (online). This experiment enabled the exploration of the response to specific climate forcings of a wide range of glaciers of different topographical characteristics in a wide range of different climatic setups, determined by all meteorological conditions from the years 19672015 (Fig. As such, these values reflect both the climatic forcing and the changing glacier geometry. When comparing our deep learning simulations with those from the Lasso, we found average cumulative MB differences of up to 17% by the end of the century (Fig. A globally complete, spatially and temporally resolved estimate of glacier mass change: 2000 to 2019. https://meetingorganizer.copernicus.org/EGU2020/EGU2020-20908.html (2020) https://doi.org/10.5194/egusphere-egu2020-20908. Lett. 6 (2018). As climate changes, so do glaciers | PNAS The Open Global Glacier Model (OGGM) v1.1. Park, and S. Beason. Durand, Y. et al. Farinotti, D., Round, V., Huss, M., Compagno, L. & Zekollari, H. Large hydropower and water-storage potential in future glacier-free basins. 65, 453467 (2019). Ser. 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. Our results confirm an over-sensitivity of temperature-index models, often used by large-scale studies, to future warming. Hastie, T., Tibshirani, R. & Friedman, J. Projected changes in surface solar radiation in CMIP5 global climate models and in EURO-CORDEX regional climate models for Europe. 47 (2020). Despite the existence of slightly different trends during the first half of the century, both the Lasso and the temperature-index model react similarly under RCP 4.5 and 8.5 during the second half of the century, compared to the deep learning model. Because of easy access and prominent location the glacier has been studied since the mid 1850's. In 1857, Lt. August Kautz crossed Nisqually Glacier during an attempt to climb the summit. longwave radiation budget, turbulent fluxes), in comparison with a future warmer climate. Each one of these cross-validations served to evaluate the model performance for the spatial, temporal and both dimensions, respectively. With this cross-validation we determined a deep learning MB model spatiotemporal (LSYGO) RMSE of 0.59m.w.e. a1 and a r2 of 0.69, explaining 69% of the total MB variance. Nisqually Glacier is well known for its kinematic waves ( Meier, 1962 ), but its mass balance has never been measured due to the difficulty of the glacier terrain. The ice thickness data for two of the largest glaciers in the French Alps were modified in order to improve data quality. The Elements of Statistical Learning. A well-established parametrization based on empirical functions50 was used in order to redistribute the annually simulated glacier-wide mass changes over each glacier. Univ. GLAMOS. Geophys. Particularly in Asia, water demand exceeds supply due to rapid population growth, with glacier . 'When the Glaciers Disappear, Those Species Will Go Extinct' The initial glacier ice thickness data for the year 2003 also differs slightly between both models. 51, 313323 (2005). Annu. All these glacier models, independently from their approach, need to resolve the two main processes that determine glacier evolution: (1) glacier mass balance, as the difference between the mass gained via accumulation (e.g. deep artificial neural networks) glacier evolution projections by modelling the regional evolution of French alpine glaciers through the 21st century. 4e) MB rates. (Photograph by Klaus J. Bayr, Keene State College, 1990) One method of measuring glaciers is to send researchers onto the ice with . Fluctuations of the Nisqually Glacier, Mt. Rainier, Washington, since This has the strongest impact under RCP 2.6, where positive MB rates are more frequent (Fig. Sign up for the Nature Briefing newsletter what matters in science, free to your inbox daily. The vertical blue and red lines indicate the distribution of extreme (top 5%) values for all 21st century projected climate scenarios, with the mean value in the center and 1 indicated by dashed lines. Since these two glaciers are expected to be some of the few large glaciers that will survive the 21st century climate, an accurate representation of their initial ice thickness has an important effect on the estimates of remaining ice. Regarding air temperature forcings, the linear Lasso MB model was found to be slightly under-sensitive to extreme positive cumulative PDD (CPDD) and over-sensitive to extreme negative CPDDs. contributed to the extraction of nonlinear mass balance responses and to the statistical analysis. Gabbi, J., Carenzo, M., Pellicciotti, F., Bauder, A. ice cap-like behaviour). We argue that such models can be suitable for steep mountain glaciers. Models were trained using the SAFRAN reanalysis dataset47, including observations of mountain regions in France for the 19582015 period. The performance of this parametrization was validated in a previous study, indicating a correct agreement with observations31. 0.78m.w.e. The maximum downvalley position of the glacier is marked by either a Ecography 40, 913929 (2017). Then in 1884, Allen Mason photographed the glacier for the first time . 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. The increase in glacier altitude also causes the solid to liquid precipitation ratio to remain relatively constant. From this behavior, inferences of past climate can be drawn. Interestingly, this matches the nonlinear, less sensitive response to summer snowfall in the ablation season of our deep learning model (Fig. 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. 3). 1960). The glacier ice volume in the French Alps at the beginning of the 21st century is unevenly distributed, with the Mont-Blanc massif accounting for about 60% of the total ice volume in the year 2015 (7.06 out of 11.64km3, Fig. J. Hosp. McKinley, Alaska, change in response to the local climate. Geophys. In order to investigate the implications of these results for flat glaciers, we performed additional synthetic experiments in order to reproduce this lack of topographical feedback (Fig. This implies that specific climatic differences between massifs can be better captured by ALPGM than GloGEMflow. Alternatively, flatter glaciers (i.e. All authors provided inputs to the paper and helped to write it. The anomaly in snowfall was evenly distributed for every month in the accumulation (October 1April 31) and ablation seasons, respectively. The Cryosphere 12, 13671386 (2018). Monitoring the Seasonal hydrology of alpine wetlands in response to snow cover dynamics and summer climate: a novel approach with sentinel-2. Nat Commun 13, 409 (2022). This allows us to assess the MB models responses at a regional scale to changes in individual predictors (Fig. Earth Syst. Our results show that the mean elevation is far more variable than the kinematic ELA ( Fig. New research suggests that climate change-induced melting of the Nisqually Glacier near Seattle, Wash., and other high-elevation glaciers will offset seasonal declines in streamflow until. J. Glaciol. Despite their limitations, temperature-index models, owing to their simplicity and parsimonious data requirements, have been widely used for large-scale glacier projections7,8. Our synthetic experiment does not account for glacier surface area shrinking either, which might have an impact on the glacier-wide MB signal. In order to investigate the effects of MB nonlinearities on ice caps, we performed the same type of comparison between simulations, but the glacier geometry update module described in the Glacier geometry evolution section was deactivated. Paul, F. et al. These synthetic experiments suggest that, for equal climatic conditions, flatter glaciers and ice caps will experience substantially more negative MB rates than steeper mountain glaciers. ADS Here, we compare our results with those from a recent study that focused on the European Alps10. J. Glaciol. Climate variations change a glacier's mass balance by affecting ablation and accumulation amounts. a Projected mean glacier altitude evolution between 2015 and 2100. The nonlinearities present in the simulated annual glacier-wide MB values were assessed by running two different glacier simulations with two different MB models. Both models agree around the average values seen during training (i.e. Since 2005, study finds that surface melt off glaciers in the North has risen by 900%. Google Scholar. This behaviour is not observed with the nonlinear model, hinting at a positive bias of linear MB models under RCP 2.6. Therefore, linear MB models present more limitations for projections of ice caps, showing a tendency to negative MB biases. 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). In order to do so, we applied a deterministic sampling process as a sensitivity analysis to both the deep learning and the Lasso MB models. This creates an interesting dilemma, with more complex temperature-index MB models generally outperforming simpler models for more climatically homogeneous past periods but introducing important biases for future projections under climate change. Glaciers are experiencing important changes throughout the world as a consequence of anthropogenic climate change1. Data 12, 19731983 (2020). Melting Glaciers: Effects on the Environment, Humans, and Biodiversity An increase in the thickness of ice in the higher portion of the Nisqually Glacier was first observed by Arthur Johnson Reference Johnson 1 about ten years ago, and the progress of this "wave" of increased ice thickness has been measured by Johnson each year since that time. ADAMONT provides climate data at 300m altitudinal bands and different slope aspects, thus having a significantly higher spatial resolution than the 0.11 from EURO-CORDEX. To obtain Hock, R. Temperature index melt modelling in mountain areas. 12, 168173 (2019). Such ice caps cannot retreat to higher elevations in a warming climate, which inhibits this positive impact on MB40 (Fig. Analysis of a 24-Year photographic record of Nisqually glacier, Mount Our projections highlight the almost complete disappearance of all glaciers outside the Mont-Blanc and Pelvoux (Ecrins region) massifs under RCP 4.5 (Fig. Nonlinear sensitivity of glacier mass balance to future climate change unveiled by deep learning, https://doi.org/10.1038/s41467-022-28033-0. The record, which was started in 1931, shows the glacier's dramatic responses to about half a century of small but significant climatic variations. "It has been pretty much doing this nonstop since the mid-1800s." The Nisqually Glacier is losing nearly a quarter of a mile in length a year, Kennard added. Despite these differences, the average altitude difference of the glaciers between both models is never greater than 50m (Fig. J.B. was supported by a NWO VIDI grant 016.Vidi.171.063. This ensures that the model is capable of reproducing MB rates for unseen glaciers and years. An accurate prediction of future glacier evolution will be crucial to successfully adapt socioeconomic models and preserve biodiversity. Cite this article. Several differences are present between ALPGM, the model used in this study, and GloGEMflow (TableS2), which hinder a direct meaningful comparison between both. Ecol. ArXiv200104385 Cs Math Q-Bio Stat (2020). 12, 909931 (2019). The model output data generated in this study have been deposited in netCDF and CSV format in a Zenodo repository under accession code Creative Commons Attribution 4.0 International. The vast majority of glaciers in the French Alps are very small glaciers (<0.01km2), that are mainly remnants from the Little Ice Age, with a strong imbalance with the current climate15. Hugonnet, R. et al. Nature 577, 364369 (2020). 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. Six, D. & Vincent, C. Sensitivity of mass balance and equilibrium-line altitude to climate change in the French Alps. These bulges, called kinematic waves, form when higher than normal snowfall builds up in the accumulation area of the glacier (c). The Cryosphere 13, 13251347 (2019). In the meantime, to ensure continued support, we are displaying the site without styles A glacier is a large mass of snow and ice that has accumulated over many years and is present year-round. Braithwaite, R. J. This is particularly important for the ablation season and for ice DDFs, which need to accommodate the progressively decreasing role that shortwave radiation will play in the future glacier surface energy budget under warmer conditions. CPDD, winter snowfall or summer snowfall) was modified for all glaciers and years. Nonetheless, since they are both linear, their calibrated parameters establishing the sensitivity of melt and glacier-wide MB to temperature variations remain constant over time. J. Hydrol. 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. Article Sci. Huss, M. & Hock, R. A new model for global glacier change and sea-level rise. Solved Activity 13.3 Nisqually Glacier Response to Climate - Chegg Winter tourism under climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation. Robinson, C. T., Thompson, C. & Freestone, M. Ecosystem development of streams lengthened by rapid glacial recession. With this study, we provide new predictions of glacier evolution in a highly populated mountain region, while investigating the role of nonlinearities in the response of glaciers to multiple future climate forcings. Nat. Moreover, these differences between nonlinear and linear models appear to come from an over-sensitivity of linear models to increasing ablation season air temperatures, when ice is exposed in a large fraction of glaciers. South American Glaciers Melting Faster, Changing Sea Level 2a). Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (2018). We previously demonstrated that this period is long enough to represent the secular trend of glacier dynamics in the region31. Glacier response to climate change Jim Salinger, Trevor Chinn, Andrew Willsman, and how fluctuations in New Zealand glaciers reflect regional climate change. & Galiez, C. A deep learning reconstruction of mass balance series for all glaciers in the French Alps: 19672015.
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