Snow Formation Research Articles

LC3 cementitious binder incorporating microencapsulated phase change materials for self-defrosting traffic surfaces

Exposed surfaces of bridge decks, viaducts and pavements incur ice formation and accumulation of snow in cold seasons, which threatens traffic safety. Mitigating this problem using traditional methods such as deicing salts have caused ecosystem damage and inflicted substantial reinforcement corrosion and surface scaling to bridge decks and pavements, thus compromising their service life and causing colossal economic loss. This paper presents an alternative solution to overcome this problem through the development of a sustainable LC3 cementitious material incorporating micro-encapsulated phase change material (MEPCM) with low phase transition temperature to delay the surface temperature drop and mitigate snow accumulation and ice formation. MEPCM was incorporated in the cementitious matrix at 0 %, 10 % and 20 % by binder mass. Paste and mortar mixtures were prepared to investigate the microstructural, mechanical, physical, and thermal properties. Test results showed that incorporating MEPCM in the LC3 matrix achieved adequate compressive strength. Thermal simulations and visual observations conducted on mortar samples in the laboratory and outdoor exposure showed that MEPCM can effectively regulate the surface temperature of the LC3 matrix and mitigate temperature drops as well as snow accumulation. Analysis of temperature data in the 2023–2024 winter season of Hamilton, Ontario, Canada indicated that the MEPCM incorporated in mortar samples could effectively regulate 40 % of the total days considered and mitigate surface ice formation and snow accumulation, which provides both economic and environmental benefits.

Production and launch studies of cryogenic pellets for the ITER disruption mitigation system

A support laboratory has been set up to study pellet production, launch and shattering of cryogenic protium, deuterium, and neon pellets for the ITER disruption mitigation system, which plans to use 28.5 × 57 mm (diameter × length) protium, neon an mixture pellets in the Shattered Pellet Injectors. Such large protium pellets have not been produced and launched before, therefore the desublimation and launch process have been studied in detail in two steps. First 19 mm diameter pellets were produced, followed by the demonstration of the final pellet size. Pellet desublimation recipes were established for all pellet types, and it was found that, under certain conditions, even the large neon pellets can be launched with a propellant gas pulse, without requiring a mechanical punch device. This is attributed to cryogenic snow formation on the surface of the pellet. Conditions for the snow formation are studied and tendencies are understood using simple calculations.

Micro- and Nano-Plastics Induced Release of Protein-Enriched Microbial Exopolymeric Substances (EPSs) in Marine Environments

Plastics are produced, consumed, and disposed of worldwide, with more than eight million tons of plastic litter entering the ocean each year. Plastic litter accumulates in marine and terrestrial environments through a variety of pathways. Large plastic debris can be broken down into micro- and nano-plastic particles through physical/mechanical mechanisms and biologically or chemically mediated degradation. Their toxicity to aquatic organisms includes the scavenging of pollutant compounds and the production of reactive oxygen species (ROS). Higher levels of ROS cause oxidative damages to microalgae and bacteria; this triggers the release of large amounts of exopolymeric substances (EPSs) with distinct molecular characteristics. This review will address what is known about the molecular mechanisms phytoplankton and bacteria use to regulate the fate and transport of plastic particles and identify the knowledge gaps, which should be considered in future research. In particular, the microbial communities react to plastic pollution through the production of EPSs that can reduce the plastic impacts via marine plastic snow (MPS) formation, allowing plastics to settle into sediments and facilitating their removal from the water column to lessen the plastic burden to ecosystems.

Marine bacteria Alteromonas spp. require UDP-glucose-4-epimerase for aggregation and production of sticky exopolymer.

Heterotrophic marine bacteria have a central role in the global carbon cycle. Well-known for releasing CO2 by decomposition and respiration, they may also contribute to particulate organic matter (POM) aggregation, which can promote CO2 sequestration via the formation of marine snow. We find that two members of the prevalent particle-associated genus Alteromonas can form aggregates comprising cells alone or cells and chitin particles, indicating their ability to drive POM aggregation. In line with their multivalent aggregation capability, both strains produce TEP, an excreted polysaccharide central to POM aggregation in the ocean. We demonstrate a genetic requirement for galE in aggregation and large TEP formation, building our mechanistic understanding of these aggregative capabilities. These findings point toward a role for heterotrophic bacteria in POM aggregation in the ocean and support broader efforts to understand bacterial controls on the global carbon cycle based on microbial activities, community structure, and meta-omic profiling.

Characterization of the surface-active exopolysaccharide produced by Halomonas sp TGOS-10: Understanding its role in the formation of marine oil snow.

In this study, we characterize the exopolymer produced by Halomonas sp. strain TGOS-10 -one of the organisms found enriched in sea surface oil slicks during the Deepwater Horizon oil spill. The polymer was produced during the early stationary phase of growth in Zobell's 2216 marine medium amended with glucose. Chemical and proton NMR analysis showed it to be a relatively monodisperse, high-molecular-mass (6,440,000 g/mol) glycoprotein composed largely of protein (46.6% of total dry weight of polymer). The monosaccharide composition of the polymer is typical to that of other marine bacterial exopolymers which are generally rich in hexoses, with the notable exception that it contained mannose (commonly found in yeast) as a major monosaccharide. The polymer was found to act as an oil dispersant based on its ability to effectively emulsify pure and complex oils into stable oil emulsions-a function we suspect to be conferred by the high protein content and high ratio of total hydrophobic nonpolar to polar amino acids (52.7:11.2) of the polymer. The polymer's chemical composition, which is akin to that of other marine exopolymers also having a high protein-to-carbohydrate (P/C) content, and which have been shown to effect the rapid and non-ionic aggregation of marine gels, appears indicative of effecting marine oil snow (MOS) formation. We previously reported the strain capable of utilising aromatic hydrocarbons when supplied as single carbon sources. However, here we did not detect biodegradation of these chemicals within a complex (surrogate Macondo) oil, suggesting that the observed enrichment of this organism during the Deepwater Horizon spill may be explained by factors related to substrate availability and competition within the complex and dynamic microbial communities that were continuously evolving during that spill.

Microbial interactions with microplastics: Insights into the plastic carbon cycle in the ocean

The fate of microplastics (MPs) in the ocean is mostly driven by (i) photo-oxidation to smaller particles and dissolved constituents, which fuel the dissolved organic carbon pool (plastic-derived DOC, pDOC), and (ii) interactions with organic matter forming sinking aggregates (marine plastic snow). Two separate laboratory experiments were conducted to investigate the two pathways of MPs. In the first experiment, we measured potential rates of microbial pDOC utilization in bottle incubations over 15 days with microbial assemblages from coastal and offshore waters. Microbial utilization of pDOC was more efficient in the coastal (72% bioreactive pDOC) compared with the offshore experiment (32% bioreactive pDOC) 15 days. Changes in bacterial cell abundance and extracellular enzyme activities (glucosidase, peptidase, esterases) indicated that a fraction of pDOC was repackaged into microbial exopolymeric substances (EPS), stimulating growth of known EPS degrading bacteria within the phyla Verrucomicrobiota and Planctomycetota. Microbial EPS likely also played a key role in our second experiment that showed the formation of marine plastic snow in roller tanks with cultured cells of Emiliana huxleyi but not with cells of an Isocrysis sp. culture. Average sinking velocities of marine plastic snow were a factor of 1.2 lower compared with marine snow without MPs. Both aggregate types showed reduced sinking velocities in a density stratified sinking column. Our results from the two experiments on (i) microbial utilization of pDOC and (ii) the formation and sinking of marine plastic snow indicate potential effects of plastic-derived compounds on microbial elemental cycles (i.e., pDOC repackaged into EPS) with consequences for the efficiency of the biological carbon pump (i.e., marine plastic snow reduces carbon export) and the fate of plastic-derived compounds in the ocean.

Effect of biopolymer concentration on the kinetics of marine snow formation

Marine snow floc refers to coagulation of microbes and marine debris in the upper ocean layers, bound together by bio-polymers such as transparent exopolymer particles (TEP) secreted by microbes. The stickiness of TEP plays a crucial role in determining the rate of marine snow floc formation. Additionally, the effect of TEP on the size distribution of marine snow influences the sinking velocity of the flocs. Using a surrogate material system, we study the kinetics of marine snow using a custom-built experimental setup, which allows direct measurement of floc size, floc number density, and floc sinking velocity as a function of TEP concentration. By comparing the experimental floc size with Smoluchowski coagulation theory, we obtain stickiness index, which increases with TEP concentration first, reaches maximum around 0.3 g/L of TEP and decreases upon further increase in TEP concentration. The experimental sinking velocity scales with floc size as ws=adb, with b ranging from 0.57 to 0.68. The exponent is slightly higher than that of 0.5 expected in the Stokes limit. This study establishes a clear link between stickiness index, sinking velocity, and polymer concentration, providing valuable insights for modelling of marine snow dynamics in deep ocean conditions. These findings contribute to a better understanding of the kinetics of marine snow formation, essential for predicting carbon sequestration within the biological carbon pump.

Retrieval of Snow Depths on Arctic Sea Ice in the Cold Season from FY-3D/MWRI Data

Snow depth is a crucial factor in the formation of snow, and its fluctuations play a significant role in the Earth’s climate system. The existing snow depth algorithms currently lack systematic quantitative evaluation, and most of them are not suitable for direct application to Chinese satellites. Therefore, a quantitative evaluation of four existing snow depth algorithms from the Advanced Microwave Scanning Radiometer 2 (AMSR2) was conducted by comparing their estimates with the measured dataset from the Operation IceBridge project (OIB). The study found that the algorithm developed by Rostosky et al. outperforms the other three algorithms in terms of correlation. However, it is unable to accurately retrieve both high and low snow depths. On the other hand, the algorithms developed by Comiso et al. and Li et al. demonstrated strong performance in correlation and statistical characteristics. Based on these results, these two algorithms were fused to enhance the accuracy of the final algorithm. The algorithm was applied to FengYun-3D/Microwave Radiation Imager (FY-3D/MWRI) data after calibration to develop a snow depth retrieval algorithm suitable for MWRI. Validation using the 2019 OIB data indicated that the algorithm had a bias and RMSE of 1 cm and 9 cm, respectively, for first-year ice (FYI) and 3 cm and 9 cm, respectively, for multi-year ice (MYI).

Energy Efficient for Heat Exchanger Refrigeration and Air Conditioning

Scientifically, it is difficult to predict the relationship between global temperature and greenhouse gas (GHG) concentrations. The climate system contains many processes that will change if warming occurs. Critical processes include heat transfer by winds and tides, the hydrological cycle involving evaporation, precipitation, runoff and groundwater and the formation of clouds, snow, and ice, all of which display enormous natural variability. The equipment and infrastructure for energy supply and use are designed with long lifetimes, and the premature turnover of capital stock involves significant costs. Economic benefits occur if capital stock is replaced with more efficient equipment in step with its normal replacement cycle. Likewise, if opportunities to reduce future emissions are taken in a timely manner, they should be less costly.

Seasonally extreme temperature events accelerate in arid northwestern China during 1979–2018

The arid northwestern China is the most vulnerable region to climate change, where the variability of seasonally extreme temperature events has profound implications for both its hydrological, ecological, and human systems. In this study, we applied 15 indicators of extreme temperature to analyze the spatial and temporal variation of its occurrence in arid northwestern China for a recent 40-year period (1979 to 2018). These extreme temperature event dynamics were then combined with atmospheric and oceanic circulation to explore their response mechanisms. Our results revealed the following: (1) Over the 40-year period, the annual average temperature in this arid zone increased at a rate of 0.4 °C/decade (p = 0.09), exceeding the national average rate (0.28 °C/decade). Apart from a few indicators, extreme temperature events (TXx, TNx, TXn and TNn) generally increased at least twice as fast as average temperature during the four seasons, especially in spring, when TNn (0.98 °C/decade) rose five times faster than did the average temperature (0.2 °C/decade). (2) Spatially, except for the Kunlun Mountains and Tarim Basin, seasonal warming occurred in most parts of the studied arid zone, being most prominent in the summer. In this season, the average number of warm nights increased (3.23 days/decade), while the average number of cold nights decreased (2.69 days/decade). (3) After the 1990s, extreme temperature events accelerated significantly. The Cold Spell Duration Indicator decreased 42% in spring and the Warm Spell Duration Indicator increased 300% in summer, from 1979 –1998 to 1999–2018, which may hasten the formation of snow and glacier melt flooding events in the spring and summer. Spatiotemporal variability in seasonally extreme temperature events was closely related to atmospheric and oceanic circulation, particularly for the AMO (r = 0.8). Altogether, these findings enhance our understanding of how to better assess shifts in extreme temperature events in response to a changing climate in arid zones.

Effects of suspended particles and dispersants on marine oil snow formation of crude oil/diesel oil.

Marine oil snow (MOS) potentially forms after an oil spill. To fully understand the mechanism of its formation, we investigated the effects of suspended particles (SP) and dispersants on MOS formation of crude oil and diesel oil by laboratory experiments. In the crude oil experiment, the SP concentration of 0.2 g L-1 was more suitable for crude oil MOS formation. The addition of dispersants significantly stimulated N and TV during MS/MOS formation of SP at 0.4 g L-1 and 0.8 g L-1 concentration (p < 0.05). Without SP, the dispersants also stimulated crude oil MOS formation. Furthermore, the concentration of SP had a significantly positive effect on the reduction of the total amount of N-alkanes (p < 0.05). In the diesel oil experiment, after adding dispersants to diesel oil, the maximum N, Dm, and TV values at a SP concentration of 0.2 g L-1 were significantly higher than those at 0.4 g L-1 and 0.8 g L-1 (p < 0.05). Besides, we found that dispersants stimulated MOS formation in diesel oil at a SP concentration of 0.2 g L-1. However, the dispersants had an inhibitory effect on diesel oil MOS formation without SP. Notably, the MOS formed by diesel oil appeared white, unlike the black MOS associated with crude oil. These findings are important for the environmental impact of oil spills and elevated SP concentrations.

STRUCTURE AND DYNAMICS OF SNOW AND ICE FORMATIONS IN THE KHIBINY MOUNTAINS IN THE 21ST CENTURY

In 1958 V.F. Perov, staff member of the Khibiny Research and Training Station of the MSU Faculty of Geography, described four snow-ice formations in the Khibiny Mountains and classified them as very small glaciers. Until our research began in 2005, these glaciers were not studied in detail. We used field observations, drilling, GIS and remote sensing methods to study the structure of the glaciers and evaluate changes in their geometry during 60 years. The snow-ice formations were drilled through for the first time and the ice cores underwent geochemical and isotope-oxygen analyses. The thickness of ice kernels varies from 0,2 to 1,6 m. Our investigations showed that despite a slight degradation, the glaciers` area remains relatively stable since 1958. This fact may be caused by the increase in solid precipitation in recent years. According to the analysis of climatic changes, in the early 2000s a decrease in snowfall was observed in the Khibiny Mountains. The maximum snow thickness at the meteorological site of the Khibiny station in 2002-2003 winter period was 55 cm. This could be a factor of more than 2 times decrease of glacier areas during 2000-2010. After 2007 there has been an increase in snow precipitation, and the maximum snow depth of 180 cm was observed in 2020, the absolute maximum for the whole period of observations (1984-2020). According to published data the increase in mean annual temperature at the plains of the Kola Peninsula is 2,3 ± 1°C during the last 50 years. However, mean monthly temperatures of the summer do not rise. We consider that, along with recently increasing snow precipitation, this is exactly what determine rather stable state of snow-ice formations in the Khibiny Mountains, which appeared to be more resistant to climate warming than mountain glaciers.

Simulating the Dynamics of the Characteristics of Snow Cover Formation Regime in the Russian Federation Territory. 2. Forest Areas of ER in the Historical Period

A procedure for calculating various characteristics of snow cover formation, based on the use of the land surface model SWAP was tested on forest areas of the European Russia for a historical period (1967−2019). The comparison of simulation results with appropriate observation data showed the good quality of reproduction of snow formation processes at these objects. Changes of the climatic values of snow cover formation characteristics in the historical period were analyzed to reveal tendencies in these changes in forest areas in the region. Thus, it was found that, despite the decrease in the duration of snow cover, there is increase in snowpack, in particular, in the maximal snow water equivalent. The difference between the characteristics of snow cover formation in the field and forest areas of European Russia was assessed. The mean values of the snow accumulation coefficient over the forest area relative to the field was found to be greater than 1.0. At the same time, the climatic changes in the historical period lead to a decrease of this characteristic in time.

The impact of internal solitary waves on deep-sea benthic organisms on the continental slope of the northern South China Sea

Internal solitary waves (ISWs) exert a significant influence on the deep-sea floor, yet little research has been conducted on their impact on benthic organisms. The objective of this study was to investigate the propagation characteristics of ISWs on the Shenhu continental slope in the northern South China Sea, as well as their mechanisms of influence on benthic activity. In-situ observation was performed at the head of the Shenhu Canyon (water depth 655m) to determine the physical characteristics of ISWs and the changes in benthic organisms. The study revealed that the abundance and density of benthic organisms were positively correlated with the time and intensity of ISWs. The abundance of benthic organisms affected by ISWs is 3-5 times that without ISWs, and the density of benthic organisms is 3-9 times. The impact induced by ISWs, including resuspension of bottom sediments, formation of marine snow, changes in the bottom boundary layer environment, and vertical transfer of seawater environmental factors, played a crucial role in the impact on benthic activity. To our limited knowledge, this is the first in-situ long-term observation study on the effects of ISWs on deep-sea benthic organisms on the continental slope of the northern South China Sea deeper than 600m, providing new insights for exploring the environmental impact of ISWs on the deep-sea bottom boundary layer.

Browning and blueing – what is the fate of polar coasts?

Covered by extensive ice sheets that often terminate as ice shelves or tidewater glaciers, polar coasts are also seasonally surrounded by sea ice. However, this “whitescape” is shrinking rapidly; the years 2012 and 2022 saw sea-ice minima for the Arctic and the Antarctic, respectively. The loss of ice is transforming these coastal areas, especially in the Arctic and West Antarctica. Meltwater transports particles, called glacial flour, from land to ocean, and when intensive enough this discharge creates “brown zones” across fjords in summer. Turbid glacial plumes hinder light penetration and darken coastal waters, thereby limiting photosynthesis, while turbulent mixing induces aggregation of particles and the resulting formation of so-called marine snow (clumps of largely organic matter that coalesce and sink through the water column) (Sci Total Environ 2021; doi.org/10.1016/j.scitotenv.2021.146491). When these particles reach the seabed, they cover benthic organisms such as this macroalga (Himantothallus grandifolius), photographed in Mackellar Inlet (62°S, Antarctic Peninsula) – a glaciomarine fjord that has not “browned” yet. Furthermore, warming intensifies iceberg calving and thus likely increases the risk of ice-scouring to benthic macroalgae in the shallows. However, glacial retreat also exposes new shallow-water habitats; by allowing phytoplankton blooms and seaweed expansion in these newly ice-free areas, this exposure process (“blueing”) increases carbon accumulation in marine systems (“blue carbon”), particularly in fjords, due to their high storage-to-sequestration efficiency (Sci Nat 2021; doi.org/10.1007/s00114-021-01748-8). In polar coastal zones, many climate-change–related feedbacks are anticipated. It is therefore crucial to assess the carbon sinks emerging due to marine ice losses; though little known, these sinks provide important negative feedbacks to climate change that could be recognized as a nature-based solution. To what extent will blueing balance the effects of advancing brown zones?

Modelling the effect of salt from road runoff on nitrification of a wastewater treatment plant

Abstract Salt (NaCl) that is being dispersed on the roads to prevent the formation of ice and snow can have positive and negative effects on nitrification rates in wastewater treatment plants (WWTPs). Based on experimental data, a numerical model has been derived to describe these effects. The numerical model has been successfully implemented in the SIMBA# simulation software and tested on a real case study, the Freistadt WWTP, located in Upper Austria. A number of parameters impacting nitrification have been investigated: inflow salt concentration, duration of the salt loading, temperature during salt loading, and increasing volumetric inflow to the WWTP during salt loading events. Simulation results revealed that salt concentration lower than 1 g NaCl/l brought improvement in nitrification rates. However, when this threshold was exceeded, inhibition of nitrification occurred. Furthermore, prolonged salt dosing exposure times brought amplification of both positive and negative effects on removal rates. Results show that salt concentration and salt load have the biggest impacts on nitrification.

Microscopic food webs under vanishing winters

Climate warming is affecting winter conditions in temperate regions, causing rapid changes in the formation and maintenance of snow and ice cover. However, little is known about planktonic and epixylon communities in dynamic river-floodplain systems in winter, as previous research has focused on the spring and summer „growing seasons“. Therefore, changes in the diversity, abundance, and functional groups of phytoplankton, zooplankton, and epixylon in the Danube floodplain (Kopački Rit Nature Park) were studied. In winter (January - March), water surfaces were covered only by a thin and patchy ice cover. Plankton and epixylon were diverse and abundant, and the changes in functional groups described the conditions prevailing in the studied waters well. The relatively stable conditions at the beginning of the study favoured the development of phytoplankton (diatoms, cryptophytes, ochrophytes), and epixylic taxa (diatoms, cyanobacteria) both belong to functional groups characteristic of shallow, turbid waters. Intense flooding and high grazing pressure reduced phytoplankton and epixylon abundance. The zooplankton community changed mainly due to the flood regime, subsequent nutrient loading, and food sources. Microfilter-feeding rotifers depended on phytoplankton, whereas microphytes that developed on epixylon were more important to the community for larger rotifers. The results suggest that further studies of floodplain winter communities are needed to understand better and predict floodplain ecology in future years.

Hydrologic Performance of Low Impact Developments in a Cold Climate

The application of the low impact development (LID) in a cold climate such as northeastern China is constrained by two unresolved research questions with regards to its infiltration potential through the winter and its varied runoff regimes between winters and summers. This study picked a typical residential district under construction in Changchun, China, and modeled the storm drainage system with and without LID facilities based on the Storm Water Management Model. The hydrological performance of LID was evaluated through various design storms and historic rain events in dry, average, and wet years. The influence of the Horton and the Green–Ampt infiltration methods on the seasonal water budgets was particularly compared since the former is universally adopted in China while the latter is more widely used in the U.S. and other countries. The results indicate that the Horton method tended to generate a higher infiltration volume than the Green–Ampt method. Consequently, when driven by the 100-year design storm, the Horton method led to a 17.4% higher outflow than the Green–Ampt method; when driven by the measured 3-year precipitation in the study area, the yearly runoff coefficients, with regards to the Horton method, were at least 1.3 times higher than those modeled by the Green–Ampt method. This finding challenged the interchangeable use of the Horton and Green–Ampt methods without tests. Furthermore, the formation of snow covers in winter also reduced the permeability of LID and its capacity of managing runoff compared to summer. However, LID still exhibited a decent potential of regulating the winter runoff in the cold region compared to the baseline, possibly owing to the presence of frequent freezing-thawing cycles.

The Seasonality of Deuterium Excess in Non‐Polar Precipitation

AbstractThe deuterium excess (d‐excess) of precipitation varies seasonally at sites across the globe, an observation that has often been linked to seasonal changes in oceanic evaporation conditions, continental moisture recycling, and subcloud raindrop re‐evaporation. However, there have been very few studies to quantify and evaluate the relative importance of these processes. Here, we revisit the mechanisms of precipitation d‐excess seasonality in low‐latitudes and mid‐latitudes through a new analysis of precipitation isotope databases along with climate reanalysis products and moisture tracking models. In low‐latitudes, the raindrop re‐evaporation effect, indicated by local relative humidity, exerts a strong and prevalent control on observed d‐excess seasonality and overprints the effect of oceanic evaporation conditions. In mid‐latitudes, the effect of oceanic evaporation conditions becomes stronger and seems dominant in the observed d‐excess seasonality. However, the ultimate d‐excess signals are produced after complex modulations by several reinforcing or competing processes, including prior distillations, moisture recycling, supersaturation in snow formation, and raindrop re‐evaporation. Among these processes, substantial increases in the proportion of recycled moisture during the warm and dry season do not produce higher precipitation d‐excess in mid‐latitude continental interiors. We develop a simple seasonal water storage model to show that contributions of previously evaporated residual water storage and higher transpiration fractions may lead to relatively low d‐excess in evapotranspiration fluxes during periods of enhanced continental moisture recycling. This study underscores the ubiquitous nonconservative behavior in d‐excess throughout the water cycle, as opposed to using d‐excess as a simple tracer for remote conditions at oceanic moisture sources.

Multi-year evolution of 75 snow and ice deposits in Schachtdolines and Shafts of recently deglaciated karst terrain: Observations from Mount Canin-Kanin, Julian Alps, Europe

Dolines and shafts are common geomorphologies in karst landscapes. When affected also by glacial processes, they are considered an example of glaciokarst landform. In high alpine karst, their typical vertical shape lends itself particularly well to the formation of snow and ice accumulations that can survive the ablation season, potentially becoming perennial. This study analyses the 12-years changes of several permanent snow-ice deposits in Schachtdolines and Shafts (SIDS) and compares them with the mass balance of surrounding external ice bodies. According to recent studies and in contrast with the rest of the Alpine glaciers, ice masses of the area are resilient to climate change and show a slightly positive mass balance in the last decade. The presence of a long term mass balance monitoring program provides an excellent basis for a robust comparison with 75 selected SIDS, all located in the Mount Canin-Kanin massif, in the Julian Alps. Six airborne LiDAR surveys performed from 2006 to 2018 at the end of the ablation season allowed accurate calculation of thickness and volume changes. The measured differences show a general increase in thickness of the SIDS with more than one meter gain, although multi-annual observed variability between the sites is high. The observed 2006–2018 positive mass balance is in agreement with the external cryosphere although SIDS appear even more resilient than the external ice patches to both interannual weather variability and climate forcing.