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Digital technology has been an integral part of transforming educational resources for students in recent decades, however, the fallout of the COVID-19 pandemic has focused education on infusion of digital technologies throughout programs to better meet students' needs. School districts have benefited from the American Rescue Plan Act funding and the surge of new or re-envisioned resources and tools launched in the aftermath of the pandemic's influence on school environments. Through this phenomenon, new opportunities have become particularly accessible to students with disabilities, and educators are in a new position to collaboratively consult to ensure resource availability. This paper discusses implications of the progressing landscape of technology in schools for providing mental health services. Using a fictional district-wide memo it illustrates how collaborative consultation can guide practitioners to use ethical considerations and ideal practices in technology integration and collaboration to meet the needs of students with disabilities.

Abstract Globally, glaciers and icefields contribute significantly to sea level rise. Here we show that ice loss from Juneau Icefield, a plateau icefield in Alaska, accelerated after 2005 AD. Rates of area shrinkage were 5 times faster from 2015–2019 than from 1979–1990. Glacier volume loss remained fairly consistent (0.65–1.01 km3 a−1) from 1770–1979 AD, rising to 3.08–3.72 km3 a−1 from 1979–2010, and then doubling after 2010 AD, reaching 5.91 ± 0.80 km3 a−1 (2010–2020). Thinning has become pervasive across the icefield plateau since 2005, accompanied by glacier recession and fragmentation. Rising equilibrium line altitudes and increasing ablation across the plateau has driven a series of hypsometrically controlled melt-accelerating feedbacks and resulted in the observed acceleration in mass loss. As glacier thinning on the plateau continues, a mass balance-elevation feedback is likely to inhibit future glacier regrowth, potentially pushing glaciers beyond a dynamic tipping point.

We present a new model for understanding ice cliff dynamics within a debris-covered glacier ablation zone. This simple energy-balance model incorporates a moving frame of reference, made necessary by the melt of the surrounding debris-covered ice. In so doing, this also formalises how different types of field measurements can be utilised and compared. Our predictions include showing: ice cliffs can endogenously select their own slope angles; that there should be an indifference between illuminated north- and south-facing ice cliff slopes; that ice cliffs grow steeper with thicker debris layers; that ice cliffs cannot stably exist below a certain critical debris thickness and that some modelling of ice cliffs (when not incorporating the moving frame) may incorrectly estimate ice mass losses. All of our results are produced using parametrisations from Baltoro Glacier, Karakoram.

Ice cliffs are features along ice sheet margins, along tropical mountain glaciers, at termini of mountain glaciers and on debris-covered glacier tongues, that have received scattered attention in literature. They cover small relative areas of glacier or margin surface respectively, but have been involved in two apparent anomalies. On the one hand, they have been identified as potential hotspots of extreme melt rates on debris-covered tongues contributing to their relatively rapid ablation, compared to the surrounding glacier surface. On the other hand, they appear where the ice margin is stable (or temporarily advancing) even under conditions of negative mass balance. In this manuscript, we recapitulate why ice cliffs remain interesting features to investigate and what we know about them so far. We conclude by suggesting to further investigate their genesis and variable morphology and their potential as windows into past climates and processes.

Turbulent fluxes make a substantial and growing contribution to the energy balance of ice surfaces globally, but are poorly constrained owing to challenges in estimating the aerodynamic roughness length (z0). Here, we used structure from motion (SfM) photogrammetry and terrestrial laser scanning (TLS) surveys to make plot-scale 2-D and 3-D microtopographic estimations of z0 and upscale these to map z0 across an ablating mountain glacier. At plot scales, we found spatial variability in z0 estimates of over two orders of magnitude with unpredictable z0 trajectories, even when classified into ice surface types. TLS-derived surface roughness exhibited strong relationships with plot-scale SfM z0 estimates. At the glacier scale, a consistent increase in z0 of ~0.1 mm d−1 was observed. Space-for-time substitution based on time since surface ice was exposed by snow melt confirmed this gradual increase in z0 over 60 d. These measurements permit us to propose a scale-dependent temporal z0 evolution model where unpredictable variability at the plot scale gives way to more predictable changes of z0 at the glacier scale. This model provides a critical step towards deriving spatially and temporally distributed representations of z0 that are currently lacking in the parameterisation of distributed glacier surface energy balance models.

We present the first direct comparison of turbulence conditions measured simultaneously over exposed ice and a 0.08 m thick supraglacial debris cover on Suldenferner, a small glacier in the Italian Alps. Surface roughness, sensible heat fluxes (~20–50 W m−2), latent heat fluxes (~2–10 W m−2), topology and scale of turbulence are similar over both glacier surface types during katabatic and synoptically disturbed conditions. Exceptions are sunny days when buoyant convection becomes significant over debris-covered ice (sensible heat flux ~ −100 W m−2; latent heat flux ~ −30 W m−2) and prevailing katabatic conditions are rapidly broken down even over this thin debris cover. The similarity in turbulent properties implies that both surface types can be treated the same in terms of boundary layer similarity theory. The differences in turbulence between the two surface types on this glacier are dominated by the radiative and thermal contrasts, thus during sunny days debris cover alters both the local surface turbulent energy fluxes and the glacier component of valley circulation. These variations under different flow conditions should be accounted for when distributing temperature fields for modeling applications over partially debris-covered glaciers.

Ongoing changes in mountain glaciers affect local water resources, hazard potential and global sea level. An increasing proportion of remaining mountain glaciers are affected by the presence of a surface cover of rock debris, and the response of these debris-covered glaciers to climate forcing is different to that of glaciers without a debris cover. Here we take a back-to-basics look at the fundamental terms that control the processes of debris evolution at the glacier surface, to illustrate how the trajectory of debris cover development is partially decoupled from prevailing climate conditions, and that the development of a debris cover over time should prevent the glacier from achieving steady state. We discuss the approaches and limitations of how this has been treated in existing modeling efforts and propose that “surrogate world” numerical representations of debris-covered glaciers would facilitate the development of well-validated parameterizations of surface debris cover that can be used in regional and global glacier models. Finally, we highlight some key research targets that would need to be addressed in order to enable a full representation of debris-covered glacier system response to climate forcing.

Spatially-distributed values of glacier aerodynamic roughness (z0) are vital for robust estimates of turbulent energy fluxes and ice and snow melt. Microtopographic data allow rapid estimates of z0 over discrete plot-scale areas, but are sensitive to data scale and resolution. Here, we use an extensive multi-scale dataset from Hintereisferner, Austria, to develop a correction factor to derive z0 values from coarse resolution (up to 30 m) topographic data that are more commonly available over larger areas. Resulting z0 estimates are within an order of magnitude of previously validated, plot-scale estimates and aerodynamic values. The method is developed and tested using plot-scale microtopography data generated by structure from motion photogrammetry combined with glacier-scale data acquired by a permanent in-situ terrestrial laser scanner. Finally, we demonstrate the application of the method to a regional-scale digital elevation model acquired by airborne laser scanning. Our workflow opens up the possibility of including spatio-temporal variations of z0 within glacier surface energy balance models without the need for extensive additional field data collection.

We present the first dedicated study into the phenomenon of ice sails. These are clean ice structures that protrude from the surface of a small number of debris-covered glaciers and can grow to heights of over 25 m. We draw together what is known about them from the academic/exploration literature and then analyse imagery. We show here that ice sails can develop by one of two mechanisms, both of which require clean ice to become surrounded by debris-covered ice, where the debris layer is shallow enough for the ice beneath it to melt faster than the clean ice. Once formed, ice sails can persist for decades, in an apparently steady state, before debris layer thickening eventually causes a reversal in the relative melt rates and the ice sails decay to merge back with the surrounding glacier surface. We support our image-based analysis with a surface energy-balance model and show that it compares well with available observations from Baltoro Glacier in the Karakoram. A sensitivity analysis of the model is performed and confirms the results from our empirical study that ice sails require a relatively high evaporative heat flux and/or a relatively low sensible heat flux in order to exist.

Glaciers in the dry Chilean Andes provide important ecological services, yet their mass balance response to past and ongoing climate change has been little studied. This study examines the recent (2002–2015), historical (1955–2005), and past (5000 m), using a combination of glaciological, geodetic, and ice core observations. Mass balance has been predominantly negative since 2002. Analysis of mass balance and meteorological data since 2002 suggests that mass balance is currently mostly sensitive to precipitation variations, while low temperatures, aridity and high solar radiation and wind speeds cause large sublimation losses and limited melting. Mass balance reconstructed by geodetic methods shows that Guanaco Glacier has been losing mass since at least 1955, and that mass loss has increased over time until present. An ice core recovered from the deepest part of the glacier in 2008 revealed that the glacier is cold-based with a −5.5°C basal temperature and a warm reversal of the temperature profile above 60-m depth attributed to the recent atmospheric warming trend. Detailed stratigraphic and stable isotope analyses of the upper 20 m of the core revealed seasonal cycles in the δ18O and δ2H records with periods varying between 0.5 and 3 m. w.e. a–1. Deuterium excess values larger than 10‰ suggest limited post-depositional sublimation, while the presence of numerous refrozen ice layers indicate significant summer melt. Tritium concentration in the upper 20 m of the core was very low, while 210Pb was undetected, indicating that the glacier surface in 2008 was at least 100 years old. Taken together, these results suggest that Guanaco Glacier formed under drastically different climate conditions than today, with humid conditions causing high accumulation rates, reduced sublimation and increased melting. Reconstruction of mass balance based on correlations with precipitation and streamflow records show periods of sustained mass gain in the early 20th century and the 1980s, separated by periods of mass loss. The southern migration of the South Pacific Subtropical High over the course of the 20th and 21st centuries is proposed as the main mechanism explaining the progressive precipitation starvation of glaciers in this area.

Mapping snow cover (SC) on glaciers at the end of the ablation period provides a possibility to rapidly obtain a proxy for their equilibrium line altitude (ELA) which in turn is a metric for the mass balance. Satellite determination of glacier snow cover, derived over large regions, can reveal its spatial variability and temporal trends. Accordingly, snow mapping on glaciers has been widely applied using several satellite sensors. However, as glacier ice originates from compressed snow, both have very similar spectral properties and standard methods to map snow struggle to distinguish snow on glaciers. Hence, most studies applied manual delineation of snow extent on glaciers. Here we present an automated tool, named ‘ASMAG’ (automated snow mapping on glaciers), to map SC on glaciers and derive the related snow line altitude (SLA) for individual glaciers using multi-temporal Landsat satellite imagery and a digital elevation model (DEM). The method has been developed using the example of the Ötztal Alps, where an evaluation of the method is possible using field-based observations of the annual equilibrium line altitude (ELA) and the accumulation area ratio (AAR) measured for three glaciers for more than 30 years. The tool automatically selects a threshold to map snow on glaciers and robustly calculates the SLA based on the frequency distribution of elevation bins with more than 50% SC. The accuracy of the SC mapping was about 90% and the SLA was determined successfully in 80% of all cases with a mean uncertainty of ±19 m. When cloud-free scenes close to the date of the highest snowline are available, a good to very good agreement of SC ratios (SCR)/SLA with field data of AAR/ELA are obtained, otherwise values are systematically higher/lower as useful images were often acquired too early in the summer season. However, glacier specific differences are still well captured. Snow mapping on glaciers is impeded by clouds and their shadows or when fresh snow is covering the glaciers, so that more frequent image acquisitions (as now provided by Sentinel-2) would improve results.

In this study, we use Pléiades tri-stereo data to generate a digital elevation model (DEM) from the Pléiades images using a workflow employing semi-global matching (SGM). We examine the DEM accuracy in complex mountain glaciated terrain by comparing the new DEMs with an independent high-quality DEM based on airborne laser scanning (ALS) data for a study area in the Austrian Alps, and with ground control points for a study area in the Khumbu Himal of Nepal. The DEMs derived using the SGM algorithm compare well to the independent high-quality ALS DEM, and the workflow produces models of sufficient quality to resolve ground control points, which are based on Pléiades imagery that are of sufficient quality to perform high spatio-temporal resolution assessments of remote areas for which no field data is available. The relative accuracy is sufficient to investigate glacier surface elevation changes below one meter, and can therefore be applied over relatively short periods of time, such as those required for annual and seasonal assessments of change. The annual geodetic mass balance for the Alpine case derived from our DEM compares well to the glaciological mass balance, and multitemporal DEM analysis is used to resolve the seasonal changes of five glaciers in the Khumbu Himal, revealing that glaciological processes such as accumulation, ablation, and glacier movement mainly take place during the summer season, with the winter season being largely inactive in the year sampled.

Accurately identifying the extent of surface snow cover on glaciers is important for extrapolating end of year mass balance measurements, constraining the glacier surface radiative energy balance and evaluating model simulations of snow cover. Here, we use auxiliary information from Riegl VZ-6000 Terrestrial Laser Scanner (TLS) return signals to accurately map the snow cover over a glacier throughout an ablation season. Three classification systems were compared, and we find that supervised classification based on TLS signal intensity alone is outperformed by a rule-based classification employing intensity, surface roughness and an associated optical image, which achieves classification accuracy of 68–100%. The TLS intensity signal shows no meaningful relationship with surface or bulk snow density. Finally, we have also compared our Snow Line Altitude (SLA) derived from TLS with SLA derived from the model output, as well as one Landsat image. The results of the model output track the SLA from TLS well, however with a positive bias. In contrast, automatic Landsat-derived SLA slightly underestimates the SLA from TLS. To conclude, we demonstrate that the snow cover extent can be mapped successfully using TLS, although the snow mass remains elusive.