nisqually glacier response to climate change

Immerzeel, W. W. et al. 1960). a1) over the French Alps. A He uniform initialization45 was used for the network parameters. Positive degree-day factors for ablation on the Greenland ice sheet studied by energy-balance modelling. Get the most important science stories of the day, free in your inbox. Three different types of cross validation were performed: a Leave-One-Glacier-Out (LOGO), a Leave-One-Year-Out (LOYO) and a Leave-Some-Years-and-Glaciers-Out (LSYGO). On the other hand, for flatter glaciers large differences between deep learning and Lasso are obtained for almost all climate scenarios (Fig. This behaviour has already been observed for the European Alps, with a reduction in DDFs for snow during the ablation season of 7% per decade34. S6). This approach is known as a cross-validation ensemble49. Google Scholar. 5). H.Z. (Springer, New York, 2009). Front. 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. longwave radiation budget, turbulent fluxes), in comparison with a future warmer climate. When it was built in the early 1900s, the road into Mount Rainier National Park from the west passed near the foot of the Nisqually Glacier, one of the mountain's longest . 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. The French Alps, located in the westernmost part of the European Alps, experience some of the strongest glacier retreat in the world15,16,17. Smiatek, G., Kunstmann, H. & Senatore, A. EURO-CORDEX regional climate model analysis for the Greater Alpine Region: performance and expected future change: climate change in the gar area. 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. Fundam. Particularly in Asia, water demand exceeds supply due to rapid population growth, with glacier . 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. The images or other third party material in this article are included in the articles Creative Commons license, unless indicated otherwise in a credit line to the material. Then in 1884, Allen Mason photographed the glacier for the first time . Despite these differences, the average altitude difference of the glaciers between both models is never greater than 50m (Fig. Our results also highlight the important role played by glacier geometry adjustment under changing climatic conditions, which is typical of mountain glaciers38. Additionally, the specific responses of the deep learning and Lasso MB models to air temperature and snowfall were extracted by performing a model sensitivity analysis. Winter tourism under climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation. The Elements of Statistical Learning. Farinotti, D., Round, V., Huss, M., Compagno, L. & Zekollari, H. Large hydropower and water-storage potential in future glacier-free basins. A.R. Bolibar, J. ALPGM (ALpine Parameterized Glacier Model) v1.1. Climatol. Summer melt was also above average. For these 32 glaciers, a total of 1048 annual glacier-wide MB values are available, covering the 19672015 period with gaps. ISSN 2041-1723 (online). Rev. The effect of glaciers shrinking to smaller extents is not captured by these synthetic experiments, but this effect is less important for flat glaciers that are dominated by thinning (Fig. J. Glaciol. Nisqually Glacier is the lengthiest of any made in North America. S5h, j, l). Provided by the Springer Nature SharedIt content-sharing initiative. Studies have warned about the use of temperature-index models for snow and ice projections under climate change for decades34,35,36. Vertical axes are different for the two analyses. Swiss glaciers have displayed less negative MB rates than French glaciers during the last decades, thus likely introducing a bias in simulations specific to the French Alps. 3 (2015). Paul, F. et al. To obtain Mer de Glace, 29km2 in 2015), which did show important differences under RCP 8.5 (up to 75%), due to their longer response time. 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. Cauvy-Frauni, S. & Dangles, O. Google Scholar. 1d, g). Since the neural network used here virtually behaves like a black box, an alternative way is needed to understand the models behaviour. Our projections highlight the almost complete disappearance of all glaciers outside the Mont-Blanc and Pelvoux (Ecrins region) massifs under RCP 4.5 (Fig. The main uncertainties in future glacier estimates stem from future climate projections and levels of greenhouse gas emissions (differences between RCPs, GCMs, and RCMs), whose relative importance progressively increases throughout the 21st century. Z. et al. Reanalysis of 47 Years of Climate in the French Alps (19582005): Climatology and Trends for Snow Cover. 2a). 1gi)26 and glaciers shrinking to higher elevations where precipitation rates are higher as a result of orographic precipitation enhancement27. This means that these flatter ice bodies, under a warming climate, will be subject to higher temperatures than their steeper counterparts. Internet Explorer). Nature 568, 382386 (2019). Glaciers are important for agriculture, hydropower, recreation, tourism, and biological communities. These are among the cascading effects linked to glacier loss which impact ecosystems and . "Seeing the rapid and devastating collapse of this incredible and critical salmon in the Nisqually River is heartbreaking," said Troutt. Geosci. Comput. A similar behaviour is observed when comparing temperature-index models to more complex models (e.g. This means that these differences linked to MB nonlinearities observed in this experiment could be even greater for such ice caps. 22, 21462160 (2009). 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 previous work31 has shown that linear MB models can be correctly calibrated for data around the mean temperature and precipitation values used during training, giving similar results and performance to deep learning. When using the linear MB model (Lasso), glaciers are close to reaching an equilibrium with the climate in the last decades of the century, which is not the case for the nonlinear MB model (deep learning). Cite this article. Glacier shrinkage in the Alps continues unabated as revealed by a new glacier inventory from Sentinel-2. The maximum downvalley position of the glacier is marked by either a Since the climate and glacier systems are known to be nonlinear13, we investigate the benefits of using a model treating, among others, PDDs in a nonlinear way in order to simulate annual glacier-wide MB at a regional scale. Earths Future 5, 418435 (2017). Taking into account that for several regions in the world about half of the glacierized volume will be lost during this first half of the 21st century, glacier models play a major role in the correct assessment of future glacier evolution. Our projections show a strong glacier mass loss for all 29 climate members, with average ice volume losses by the end of the century of 75%, 80%, and 88% compared to 2015 under RCP 2.6 (9%, n=3), RCP 4.5 (17% +11%, n=13) and RCP 8.5 (15% +11%, n=13), respectively (Fig. Braithwaite, R. J. Res. Mt. Glaciers are experiencing important changes throughout the world as a consequence of anthropogenic climate change1. 1). Nisqually Glacier is perhaps the most visited, best-surveyed glacier on Mount Rainier. 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. In the United States, glaciers can be found in the Rocky Mountains, the Sierra Nevada, the Cascades, and throughout Alaska. 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. performed simulations with another glacier model, provided results for comparison, and contributed to the glaciological analyses. Geophys. volume13, Articlenumber:409 (2022) J. Glaciol. Both models agree around the average values seen during training (i.e. Gardent, M., Rabatel, A., Dedieu, J.-P. & Deline, P. Multitemporal glacier inventory of the French Alps from the late 1960s to the late 2000s. Sci. snowfall, avalanches and refreezing) and the mass lost via different processes of ablation (e.g. Nonlinear sensitivity of glacier mass balance to future climate change unveiled by deep learning, https://doi.org/10.1038/s41467-022-28033-0. Glob. Use the Previous and Next buttons to navigate the slides or the slide controller buttons at the end to navigate through each slide. 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. Despite the existence of a wide variety of different approaches to simulate glacier dynamics, all glacier models in GlacierMIP rely on MB models with linear relationships between PDDs and melt, and precipitation and accumulation. Bolibar, J., Rabatel, A., Gouttevin, I. et al. Additionally, glacier surface area was found to be a minor predictor in our MB models31. Geophys. 10, 42574283 (2017). Glaciers are large-scale, highly sensitive climate instruments which, ideally, should be picked up and weighed once a year. McKinley, Alaska, change in response to the local climate. Lett. Univ. 1 and S1). This ensures that the model is capable of reproducing MB rates for unseen glaciers and years. 3). Climate predictors consist of: the annual CPDD, winter snowfall, summer snowfall, monthly mean temperature and monthly snowfall. Interestingly, our analysis indicates that more complex models using separate DDFs for ice, firn and snow might introduce stronger biases than more simple models using a single DDF. A similar trend is under way. 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. Peer reviewer reports are available. Across the globe, glaciers are decreasing in volume and number in response to climate change. Consortium, R. G. I. Randolph Glacier Inventory 6.0 (2017) https://doi.org/10.7265/N5-RGI-60. Appl. https://doi.org/10.1016/B978-0-12-821575-3.00009-8. Rainier is considered by the USGS to be one of the most threatening volcanoes in the Cascade Mountains. 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. Conversely, the linear MB model appears to be over-sensitive to extreme positive and negative snowfall anomalies. 3). This behaviour is not observed with the nonlinear model, hinting at a positive bias of linear MB models under RCP 2.6. 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. Ice-surface altitude changes of as much as 25 meters occurred between 1944 and 1955. Therefore, linear MB models present more limitations for projections of ice caps, showing a tendency to negative MB biases. Changes in DDFs with respect to air temperature also strongly depend on albedo, with ice presenting a substantially more nonlinear response than snow. 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. 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. Therefore, their sensitivities to the projected 21st century increase in PDDs are linear. 51, 313323 (2005). 51, 573587 (2005). Relatively minor climate changes during the Little Ice Age (A.D. 1200-1850) impart significant glacial responses. 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. As previously mentioned, here these differences are computed at regional level for a wide variety of glaciers. Pellicciotti, F. et al. MATH Envelopes indicate based on results for all 660 glaciers in the French Alps for the 19672015 period. Res. Millan, R., Mouginot, J., Rabatel, A., & Morlighem, M. Ice velocity and thickness of the worlds glaciers. 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. 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. Multiple copies of this dataset were created, and for each individual copy a single predictor (i.e. 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. GloGEMflow10 is a state-of-the-art global glacier evolution model used in a wide range of studies, including the second phase of GlacierMIP7,8. a1 and a r2 of 0.69, explaining 69% of the total MB variance. 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). 60, 867878 (2014). The largest snow depths measured this spring exceeded 10 meters on Nisqually Glacier and 7 meters on Emmons. J. Glaciol. provided glacier mass balance data and performed the glaciological analyses. This dataset applies a statistical adjustment specific to French mountain regions based on the SAFRAN dataset, to EURO-CORDEX26 GCM-RCM-RCP members, covering a total of 29 different future climate scenarios for the 20052100 period. 21, 229246 (2021). CAS This implies that specific climatic differences between massifs can be better captured by ALPGM than GloGEMflow. However, glacier projections under low-emission scenarios and the behaviour of flatter glaciers and ice caps are likely to be biased by mass balance models with linear sensitivities, introducing long-term biases in sea-level rise and water resources projections. In order to avoid overfitting, MB models were thoroughly cross-validated using all data for the 19672015 period in order to ensure a correct out-of-sample performance. We previously demonstrated that this period is long enough to represent the secular trend of glacier dynamics in the region31. a deep artificial neural network) or the Lasso (regularized multilinear regression)30. creates a Nisqually Glacier response similar to those seen from its historical waves, suggesting that there are other factors contributing to kinematic wave formation, and 4) the Nisqually . 49, 26652683 (2017). Nature Communications (Nat Commun) 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. Glacier-wide MB is simulated annually for individual glaciers using deep learning (i.e. Strong Alpine glacier melt in the 1940s due to enhanced solar radiation. The main reason for their success comes from their suitability to large-scale studies with a low density of observations, in some cases displaying an even better performance than more complex models12. 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. Vis. We also use this method to extract glacier borderlines from satellite images across the western Lenglongling mountains. Another source of discrepancy between both models comes from the different MB data used to calibrate or train the MB models. Alternatively, the Lasso model used here includes 13 DDFs: one for the annual CPDDs and 12 for each month of the hydrological year. 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. Several aquatic and terrestrial ecosystems depend on these water resources as well, which ensure a base runoff during the warmest or driest months of the year6. 2013). J.B. was supported by a NWO VIDI grant 016.Vidi.171.063. 14, 815829 (2010). 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. the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Publishers note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The training was performed with an RMSprop optimizer, batch normalization46, and we used both dropout and Gaussian noise in order to regularize it. 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. 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. Interestingly, future warmer temperatures do not affect annual snowfall rates on glaciers as a result of both higher precipitation rates in the EURO-CORDEX ensemble (Fig. Zekollari, H., Huss, M. & Farinotti, D. Modelling the future evolution of glaciers in the European Alps under the EURO-CORDEX RCM ensemble. Together with recent findings by another study41 highlighting the increased uncertainties in ice thickness distribution estimates of ice caps compared to mountain glaciers, our results raise further awareness on the important uncertainties in glacier projections for ice caps. 48, 24872512 (2009). Nature 575, 341344 (2019). The scheme simulates the mass balance as well as changes of the areal . These results are in agreement with the main known drivers of glacier mass change in the French Alps28. This creates a total of 34 input predictors for each year (7 topographical, 3 seasonal climate, and 24 monthly climate predictors). This translates into a more linear response to air temperature changes compared to the ablation season (Fig. Conf. 2) and RCP 8.5 by the end of the century. 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. Alternatively, flatter glaciers (i.e. Preliminary results suggest winter accumulation in 2018 was slightly above the 2003-2017 average for the Emmons & Nisqually. The new research suggests that the world's glaciers are disappearing more quickly than scientists previously estimated, and they . Nonetheless, a better understanding of the underlying processes guiding these nonlinear behaviours at large geographical scales is needed. This allows us to assess the MB models responses at a regional scale to changes in individual predictors (Fig. "The Patagonia Icefields are dominated by so-called 'calving' glaciers," Rignot said. a1 and an r2 of 0.3531. 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. The ice thickness data for two of the largest glaciers in the French Alps were modified in order to improve data quality. In order to improve the comparability between both models, a MB bias correction was applied to GloGEMflows simulated MB, based on the average annual MB difference between both models for the 20032015 period (0.4m.w.e. Years in white in c-e indicate the disappearance of all glaciers in a given massif. In this study, we investigate the future evolution of glaciers in the French Alps and their nonlinear response to multiple climate scenarios. A global synthesis of biodiversity responses to glacier retreat. Despite the differences in the two modelling approaches (TableS2), both regional glacier volume projections present relatively similar results by the end of the century, with volume differences ranging between 14% for RCP 2.6 to less than 2% for RCP 4.5 (Fig. energy balance), with differences increasing when the conditions considerably differ from the calibration period33. Therefore, an alternative nonlinear parameterization for the reduction in MB sensitivity under increasing air temperatures would be useful. All values correspond to ensemble means under RCP 4.5. During the last decade, various global glacier evolution models have been used to provide estimates on the future sea-level contribution from glaciers7,8. On Mount Rainier, elevation surveys of Nisqually Glacier are regularly made to determine changes in the elevation of the surface. Our results suggest that, except for the lowest emissions climate scenarios and for large glaciers with long response times, MB models with linear relationships for PDDs and precipitation are suitable for mountain glaciers with a marked topographical feedback. 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). Lett. Dyn. These conclusions drawn from these synthetic experiments could have large implications given the important sea-level contribution from ice cap-like ice bodies8. Since both MB models also include monthly temperature data as predictors, this CPDD anomaly was distributed evenly between the ablation season (April 1September 30), following the expected increase in mostly summer temperatures instead of winter temperatures in the future (Fig. PubMedGoogle Scholar. Share sensitive information only on official, secure websites.. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate. The application of a non-linear back-propagation neural network to study the mass balance of Grosse Aletschgletscher, Switzerland. 4). The anomaly in snowfall was evenly distributed for every month in the accumulation (October 1April 31) and ablation seasons, respectively. 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. Robinson, C. T., Thompson, C. & Freestone, M. Ecosystem development of streams lengthened by rapid glacial recession. As for the MB modelling approach, a detailed explanation on this method can be found in a previous dedicated paper on the methods31.

Hattie Jacques And Eric Sykes Relationship, Yucaipa School District Board Members, Articles N