nisqually glacier response to climate change

Geophys. These are among the cascading effects linked to glacier loss which impact ecosystems and . J.B. developed the main glacier model, performed the simulations, analysed the results, and wrote the paper. 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. Geosci. Future high-mountain hydrology: a new parameterization of glacier retreat. This approach is known as a cross-validation ensemble49. 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. J. Clim. is central to a glacier's response: Fig.2ashows 1L.t/for a warming trend of 1 C per century, for three glaciers with dierent (and fixed ). A recent study he did found that 80 percent of the glaciers in Alberta and British Columbia could melt in the next 50 years. GlacierMIP A model intercomparison of global-scale glacier mass-balance models and projections. The position of the front of the wave will be defined as the transverse line across the glacier where the flow of . Front. 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. Huss, M. et al. Data 12, 18051821 (2020). The training was performed with an RMSprop optimizer, batch normalization46, and we used both dropout and Gaussian noise in order to regularize it. Lett. 48, 24872512 (2009). These predictors are composed of: the mean glacier altitude, maximum glacier altitude, slope of the lowermost 20% altitudinal range of the glacier, glacier surface area, latitude, longitude and aspect. Robinson, C. T., Thompson, C. & Freestone, M. Ecosystem development of streams lengthened by rapid glacial recession. The Cryosphere 12, 13671386 (2018). Cross-validation strategies for data with temporal, spatial, hierarchical, or phylogenetic structure. 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. Dyn. Bolibar, J., Rabatel, A., Gouttevin, I. Zemp, M. et al. This implies that current global glacier mass loss projections are too low for the lowest emissions climate scenarios and too high for the highest emissions ones, which has direct consequences for related sea-level rise and water resources projections. Interestingly, this matches the nonlinear, less sensitive response to summer snowfall in the ablation season of our deep learning model (Fig. These different behaviours and resulting biases can potentially induce important consequences in long-term glacier evolution projections. 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. This annual geometry adjustment accounts for the effects of glacier retreat on the climate signal received by glaciers. 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. The Karakoram and the Himalayan mountain range accommodate a large number of glaciers and are the major source of several perennial rivers downstream. "The Patagonia Icefields are dominated by so-called 'calving' glaciers," Rignot said. Rainier, Washington. 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. (Photograph by Klaus J. Bayr, Keene State College, 1990) One method of measuring glaciers is to send researchers onto the ice with . Particularly in Asia, water demand exceeds supply due to rapid population growth, with glacier . 799904) and from the Fonds de la Recherche Scientifique FNRS (postdoctoral grant charg de recherches). contributed to the extraction of nonlinear mass balance responses and to the statistical analysis. S5 and S6). 1d, g). Multiple copies of this dataset were created, and for each individual copy a single predictor (i.e. 31, n/an/a (2004). Fundam. Tour. 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. Planet. 2a and S3). Glacier surface mass changes are commonly modelled by relying on empirical linear relationships between PDDs and snow, firn or ice melt8,9,10,29. "Their numbers have gone from regularly exceeding 50,000 adult salmon in the Nisqually to about 5,000 last year." The Nisqually River near its glacial origins. Glaciers and ice caps are experiencing strong mass losses worldwide, challenging water availability, hydropower generation, and ecosystems. 51, 573587 (2005). Both the Lasso and the temperature-index MB model rely on linear relationships between PDDs, solid precipitation and MB. This behaviour is not observed with the nonlinear model, hinting at a positive bias of linear MB models under RCP 2.6. 12, 168173 (2019). 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. 21, 229246 (2021). Our projections highlight the almost complete disappearance of all glaciers outside the Mont-Blanc and Pelvoux (Ecrins region) massifs under RCP 4.5 (Fig. Bolibar, J., Rabatel, A., Gouttevin, I. et al. Envelopes indicate based on results for all 660 glaciers in the French Alps for the 19672015 period. J.B. was supported by a NWO VIDI grant 016.Vidi.171.063. 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. This behaviour is particularly clear for summer snowfall, for which the differences are the largest (Fig. Glacier topography is a crucial driver of future glacier projections and is expected to play an important role in determining the magnitude that nonlinearities will have on the mass balance. A recent Northern Hemisphere temperature reconstruction indicates an oscillating temperature drop from A.D. 1000-1850 of about 0.2C with a subsequent and still continuing warming of nearly 0.8C ( 3 ). We ran glacier evolution projections for both the deep learning and Lasso MB models, but we kept the glacier geometry constant, thus preserving the glacier centroid where the climate data is computed constant through time. Our synthetic experiment does not account for glacier surface area shrinking either, which might have an impact on the glacier-wide MB signal. S4). Overall, this results in linear MB models overestimating both extreme positive (Fig. 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. Roe, G. H. Orographic precipitation. Nature Communications thanks Mohd Anul Haq, Lauren Vargo, and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. 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. https://doi.org/10.1038/s41467-022-28033-0, DOI: https://doi.org/10.1038/s41467-022-28033-0. Bartk, B. et al. A glacier is a large mass of snow and ice that has accumulated over many years and is present year-round. Alternatively, the comparisons against an independent large-scale glacier evolution model were less straightforward to achieve. In order to overcome these differences, some adaptations were performed to the GloGEMflow output, accompanied with some hypotheses to ensure a realistic comparison. Our results confirm an over-sensitivity of temperature-index models, often used by large-scale studies, to future warming. This is well in agreement with the known uncertainties of glacier evolution models, with glacier ice thickness being the second largest uncertainty after the future GCM-RCM-RCP climate members used to force the model29. Through his research in that area, he's seen firsthand the impact of climate change and has been studying the long-term effects of a warming planet. This suggests that linear MB models are adequate tools for simulating MB of mountain glaciers with important topographical adjustment, with the only exception being the most optimistic climate scenarios and glaciers with long response times. Ecol. 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. S5b). Jordi Bolibar. Here, with our newly presented approach, we were able for the first time to quantify the effect that stationary parameters in temperature-index mass balance models have on transient glacier evolution. 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. Immerzeel, W. W. et al. Xu, B., Wang, N., Chen, T. & Li, M. Empirical Evaluation of Rectified Activations in Convolutional Network. The projections without glacier geometry adjustment explore the behaviour of glaciers which cannot retreat to higher elevations (i.e. energy balance), with differences increasing when the conditions considerably differ from the calibration period33. In order to investigate the effects of MB nonlinearities on flatter glaciers, we conducted a synthetic experiment using the French Alps dataset. Deep artificial neural networks (ANNs) are nonlinear models that offer an alternative approach to these classic methods. Winter tourism under climate change in the Pyrenees and the French Alps: relevance of snowmaking as a technical adaptation. 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. 4e). This work was funded by the Labex OSUG@2020 (Investissements davenir, ANR10 LABX56) and the Auvergne-Rhne-Alpes region through the BERGER project. Ten . The original ice thickness estimates of the methods used by both models are different10,32, and for ALPGM we performed some additional modifications to the two largest glaciers in the French Alps (see Glacier geometry evolution for details). A similar behaviour is observed when comparing temperature-index models to more complex models (e.g. Clim. The French Alps, located in the westernmost part of the European Alps, experience some of the strongest glacier retreat in the world15,16,17. Graphics inspired by Hock and Huss40. For these 32 glaciers, a total of 1048 annual glacier-wide MB values are available, covering the 19672015 period with gaps. Google Scholar. The climatic forcing comes from high-resolution climate ensemble projections from 29 combinations of global climate models (GCMs) and regional climate models (RCMs) adjusted for mountain regions for three Representative Concentration Pathway (RCP) scenarios: 2.6, 4.5, and 8.525. Swiss Glacier Mass Balance (release 2019). Each one of these models was created by training a deep learning model with the full dataset except all data from a random glacier and year, and evaluating the performance on these hidden values. Therefore, their sensitivities to the projected 21st century increase in PDDs are linear. 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. J. Geophys. These measurements of surface elevation were begun by personnel of the Tacoma The Nisqually Glacier is one of the larger glaciers on the southwestern face of Mount Rainier in the U.S. state of Washington.The glacier is one of the most easily viewed on the mountain, and is accessible from the Paradise visitor facilities in Mount Rainier National Park.The glacier has had periods of advance and retreat since 1850 when it was much more extensive. 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. a deep artificial neural network) or the Lasso (regularized multilinear regression)30. We argue that such models can be suitable for steep mountain glaciers. Summer climate is computed between April 1st and September 30th and winter climate between October 1st and March 31st. Grenoble Alpes, Universit de Toulouse, Mto-France, CNRS, CNRM, Centre dtudes de la Neige, Grenoble, France, Department of Geoscience and Remote Sensing, Delft University of Technology, Delft, Netherlands, Laboratoire de Glaciologie, Universit Libre de Bruxelles, Brussels, Belgium, Univ. Previous studies on 21st century large-scale glacier evolution projections have covered the French Alps7,8. To obtain Then in 1884, Allen Mason photographed the glacier for the first time . Article ice caps) that are found in other glacierized regions such as the Arctic, where the largest volumes of glacier ice (other than the ice sheets) are stored32, cannot retreat to higher elevations. 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. Earth Syst. 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. The advantage of this method is that by only changing the MB model, we can keep the rest of the model components (glacier dynamics and climate forcing) and parameters the same in order to have a controlled environment for our experiment. You are using a browser version with limited support for CSS. Overall, the evolving glaciers are expected to undergo rather stable climate conditions under RCP 4.5, but increasingly higher temperatures and rainfall under RCP 8.5 (Fig. 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. Arch. Rveillet, M. et al. A similar trend is under way. Due to the statistical nature of the Lasso model, the response to snowfall anomalies is also highly influenced by variations in PDDs (Fig. S7). However, both the climate and glacier systems are known to react non-linearly, even to pre-processed forcings like PDDs13, implying that these models can only offer a linearized approximation of climate-glacier relationships. With this cross-validation we determined a deep learning MB model spatiotemporal (LSYGO) RMSE of 0.59m.w.e. 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). Monitoring the Seasonal hydrology of alpine wetlands in response to snow cover dynamics and summer climate: a novel approach with sentinel-2. 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). Six, D. & Vincent, C. Sensitivity of mass balance and equilibrium-line altitude to climate change in the French Alps. 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. Nat Commun 13, 409 (2022). On Mount Rainier, elevation surveys of Nisqually Glacier are regularly made to determine changes in the elevation of the surface. 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. 3). Average ice velocities on the Nisqually Glacier were previously measured at approximately 200 mm/day (8 in) (Hodge 1974). Geophys. Fr Hydrobiol. GloGEMflow relies on EURO-CORDEX ensembles26, whereas ALPGM uses ADAMONT25, an adjusted version of EURO-CORDEX specifically designed for mountain regions. Res. (a) Topographical predictors were computed based on the glaciers annually updated digital elevation model (DEM). Many studies have investigated the effects of climate change on glacier runoff using observations or modelling, with a recent focus on High Mountain Asia 14,16,17 and the Andes 18,19,20.The degree . 3). Nonetheless, a close inspection of the annual glacier-wide MB rates from both models reveals similar patterns to those found when comparing deep learning and Lasso approaches (Figs. By the end of the century, we predict a glacier volume loss between 75 and 88%. J. R. Stat. Google Scholar. 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. Model Dev. Article Strong Alpine glacier melt in the 1940s due to enhanced solar radiation. 51, 313323 (2005). S10). Paul, F. et al. I.G. 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. 3). These bulges, called kinematic waves, form when higher than normal snowfall builds up in the accumulation area of the glacier (c). Both DEMs were resampled and aligned at a common spatial resolution of 25m. For each glacier, an individual parameterized function was computed representing the differences in glacier surface elevation with respect to the glaciers altitude within the 19792011 period. 4e) MB rates. These differences in the received climate signal are explained by the retreat of glaciers to higher altitudes, which keep up with the warming climate in RCP 4.5 but are outpaced by it under RCP 8.5. a Glacier-wide annual MB, b Ice volume, c Glacier area. Conversely, during the accumulation season, glaciers are mostly covered by snow, with a much higher albedo and a reduced role of shortwave radiation in the MB that will persist even under climate change. Univ. deep artificial neural networks) glacier evolution projections by modelling the regional evolution of French alpine glaciers through the 21st century. Internet Explorer). & Galiez, C. A deep learning reconstruction of mass balance series for all glaciers in the French Alps: 19672015. The processing chain for extracting glacier outlines from images is composed of four steps: (1) calculation of band ratio, (2) selection of threshold value, (3) creation of binary image and (4) manual digitization. This means that these flatter ice bodies, under a warming climate, will be subject to higher temperatures than their steeper counterparts. The mountain has three major peaks: Liberty Cap, Point Success, and Columbia Crest (the latter is the summit, located on the rim of the caldera). Gabbi, J., Carenzo, M., Pellicciotti, F., Bauder, A. The Elements of Statistical Learning. MathSciNet Our results point out that this lack of topographical feedback leads to an increased frequency of extreme negative MB rates and to more pronounced differences between the nonlinear and linear MB models (Figs. Annual glacier-wide mass balance (MB) is estimated to remain stable at around 1.2m.w.e. Glob. S1a). 185, 235246 (2014). a1 and a r2 of 0.69, explaining 69% of the total MB variance. Comput. Analyses were made of the annual photographs . J. Glaciol. 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. New methods bridging the gap between domain-specific equations and machine learning are starting to arise42, which will play a crucial role in further investigating the physical processes driving these nonlinear climate-glacier interactions.
Yeovil Town Players Wages, Intune Install Behavior Greyed Out, Why Does Smoked Meat Give Me Gas, Overcurrent Devices Do Not Have To Be Readily Accessible If, Surfline Maroochydore, Articles N