Ice Patches Research Articles

Survey of remnant seasonal ice patches at southern polar Mars

On Mars after the recession of the seasonal polar ice cap, small icy patches in shady and/or low thermal conductivity places are left behind. These regions are then illuminated by direct sunlight during the summer, warm up and in an ideal case a liquid phase could emerge. This work is surveying HiRISE images for such ice patches and found 148 images with ice patches on them out of the 730 images that fit the selection criteria of location and season. Their separation of ice from other bright patches, like clouds or lighter shades of surface layers and rocks was possible by their bluish color and strong connection to local topography Images with ice patches ranged between 140° and 200° solar longitude in the latitude band between −40° and − 60°. The diameter of the ice patches ranges between 1.5 and 300 m, and they remain on the surface even after the seasonal polar cap has passed over the area for at least the duration range of 1.5–139 Martian days. This range of duration indicates not ephemerally formed ice in the night but longer presence at the surface.

The radiative and geometric properties of melting first-year landfast sea ice in the Arctic

Abstract. In polar regions, sea ice is a crucial mediator of the interaction between Earth's atmosphere and oceans. Its formation and breakup is intimately connected with large-scale climatic processes, local weather patterns, and the use of sea ice in coastal Arctic regions by Indigenous people. In order to investigate the physical phenomena at the heart of this process, a set of targeted, intensive observations were made over spring sea ice melt and breakup in Kotzebue Sound, Alaska. These observations were planned and executed through a collaborative effort in which an Indigenous Elder advisory council from Kotzebue and scientists participated in co-production of hypotheses and observational research, including a stronger understanding of the physical properties of sea ice during spring melt. Here we present the results of observations performed using high-endurance, fixed-wing uncrewed aerial vehicles (UAVs) containing custom-built scientific payloads. Repeated flights over the measurement period captured the early stages of the transition from a white, snow-covered state to a broken-up, bare blue-green state. We found that the reflectance of sea ice features depends strongly on their size. Snow patches get darker as they get smaller, an effect owed to the geometric relationship between the bright interior and the darker, melting feature edges. Conversely, bare patches get darker as they get larger. For the largest ice features observed, bare blue-green ice patches were found to be ≈ 20 % less reflective than average across all observational cases, while large snowy white ice patches were found to be ≈ 20 % more reflective than that same average.

Radiocarbon dating of naturally shed reindeer antlers melted out of retreating and down-wasting ice patches and ice caps in western Norway

A rise in summer temperatures, especially since the turn of the 21st century, has caused negative mass balance and marginal retreat of ice caps and ice patches in western Norway. Twentytwo naturally shed reindeer antlers found at retreating and down-melting margins of fourteen retreating ice patches and ice caps on mountain summits in western Norway during the recent decades have been radiocarbon dated. The reindeer antlers show no evidence of being sawed or cut off the skull or any engravings/scrape marks if the antlers had been handled by humans. The oldest reindeer antler in this study dates at 2201-2132 cal. yr BCE. Four dated antlers fall within the age range 2300-2000 cal. yr BCE. Single dates fall within the time ranges 1100 to 1000, 900 to 800, and 500 to 300 cal. yr BCE. Four dated antlers are within the time range 200 BCE to 100 cal. yr CE and two dated antlers fall within the time range 600 to 800 cal. yr CE. Finally, fifteen dates fall within the time range 1300-1900 cal. yr CE, the highest number (n=11) between 1300 and 1600 cal. yr CE. The temperature decline and increased precipitation causing advancing glaciers and ice caps, accompanied by growing ice patches during the Neoglacial period, including the early phase of the Little Ice Age, provided good preservation conditions for the reindeer antlers during the Little Ice Age, with extensive ice and snow cover in the high mountains in western Norway.

Ice-inhabiting species of Bdelloidea Rotifera reveal a pre-Quaternary ancestry in the Arctic cryosphere.

Historical climate data indicate that the Earth has passed through multiple geological periods with much warmer-than-present climates, including epochs of the Miocene (23-5.3 mya BP) with temperatures 3-4°C above present, and more recent interglacial stages of the Quaternary, for example, Marine Isotope Stage 11c (approx. 425-395 ka BP) and Middle Holocene thermal maximum (7.5-4.2 ka BP), during which continental glaciers may have melted entirely. Such warm periods would have severe consequences for ice-obligate fauna in terms of their distribution, biodiversity and population structure. To determine the impacts of these climatic events in the Nordic cryosphere, we surveyed ice habitats throughout mainland Norway and Svalbard ranging from maritime glaciers to continental ice patches (i.e. non-flowing, inland ice subjected to deep freezing overwinter), finding particularly widespread populations of ice-inhabiting bdelloid rotifers. Combined mitochondrial and nuclear DNA sequencing identified approx. 16 undescribed, species-level rotifer lineages that revealed an ancestry predating the Quaternary (> 2.58 mya). These rotifers also displayed robust freeze/thaw tolerance in laboratory experiments. Collectively, these data suggest that extensive ice refugia, comparable with stable ice patches across the contemporary Norwegian landscape, persisted in the cryosphere over geological time, and may have facilitated the long-term survival of ice-obligate Metazoa before and throughout the Quaternary.

First records of a new Europe’s southernmost glacier found in Southern Albania

Several perennial snow and ice bodies have been recently studied and monitored in three mountain massifs across the Balkan Peninsula: Prokletije (Northern Albania), Durmitor (Montenegro) and Pirin (Bulgaria), the two glacierets in the Pirin Mountains until soon considered as southernmost of their kind in Europe. In September 2022 a relatively large snow field (about 1.5 ha) was discovered and described for a first time in the glacial cirque Gryka e Kazanit in the Nëmerçka Mountains of Southern Albania. The snow accumulation lies on 1550–1650 m a.s.l. below a vertical limestone cliff with a height of almost 1000 m. The site was visited again in November 2023, when the snow field diminished its size to less than 1 ha. At the same time, multi-annual firn layers were exposed under the last year snow, with depth at least several metres, and indications were observed of ice, buried in the debris cover below. Newest findings indicate that the studied snow-firn body is a glacieret similar to those found in the Pirin Mountains. On a longer-term, nine perennial snow/firm bodies on the Balkans resemble small glaciers rather than snow and ice patches at least under current climatic conditions. Situated on 40°08′ Northern latitude, the newly discovered Nemërçka Glacieret is nominated to be the southernmost glacier in Europe.

Off the ice: an oral history of the Swift Current Broncos’ relationship with hockey

In 1986, the Swift Current Broncos departed in their team bus for a Canadian Hockey League game. With inclement weather affecting driving conditions, the bus hit a patch of ice – flipping the bus onto its side and killing four players and injuring others. Through interviews with six survivors of the accident, this study examined how tragedy closely linked to sport can impact a player’s relationship with the game; sport’s role in the healing process; and how an athlete can maintain—or ­rekindle—their passion for sport over time. Interviewees experienced feelings of solace in the team environment and welcomed hockey’s ability to serve as a distraction. These comforts provided only temporary relief, however, as players explored various forms of therapy years after the accident. Despite difficulties, participants celebrated hockey and characteristics of their hockey experience, and cited maintained involvement with the sport 37 years after the accident.

The Alligator Lake Throwing Dart, Yukon, Canada

On August 25th, 2018, the Yukon Ice Patch Research Group recovered a 6,000-year-old segmented throwing dart from site JcUu-11 (Hare et al. 2004) located in the traditional territories of the Carcross/Tagish First Nation and the Kwanlin Dün First Nation, Yukon Canada. The discovery was the result of a dramatic retreat of an ice patch over a period of 23 days. This discovery is the first entirely complete atlatl throwing dart retrieved from an archaeological site in arctic and subarctic North America. Beyond its remarkably state of preservation, the artifact offers insights on material use and artifact design that may have significant implications for archaeological interpretations of First Nations’ hunting traditions.

The Hunters of the Alpine Ice

The Hunters of the Alpine Ice exhibition originated from a research collaboration between territorial archaeologists and the first nation Mountain Dene, or Shúhtagot’ine, of the community of Tulita, in Canada’s Northwest Territories (NWT). The exhibit was part of the public communications component of the NWT Ice Patch Study, which was an International Polar Year (2007–2008) research project.

Secrets from the Ice

I heartily recommend the documentary film Secrets from the Ice (https://www.youtube.com/watch?v=WNq_pqUEcb8), featuring the methods, discoveries, and especially the cultural significance of the emerging field of ice patch archaeology.

Organic layers preserved in ice patches: A new record of Holocene environmental change on the Beartooth Plateau, USA

Growing season temperatures play a crucial role in controlling treeline elevation at regional to global scales. However, understanding of treeline dynamics in response to long-term changes in temperature is limited. In this study, we analyze pollen, plant macrofossils, and charcoal preserved in organic layers within a 10,400-year-old ice patch and in sediment from a 6000-year-old wetland located above present-day treeline in the Beartooth Mountains, Wyoming, to explore the relationship between Holocene climate variability and shifts in treeline elevation. Pollen data indicate a lower-than-present treeline between 9000 and 6200 cal yr BP during the warm, dry summer and cold winter conditions of the early Holocene. Increases in arboreal pollen at 6200 cal yr BP suggest an upslope treeline expansion when summers became cooler and wetter. A possible hiatus in the wetland record at ca. 4200–3000 cal yr BP suggests increased snow and ice cover at high elevations and a lowering of treeline. Treeline position continued to fluctuate with growing season warming and cooling during the late-Holocene. Periods of high fire activity correspond with times of increased woody cover at high elevations. The two records indicate that climate was an important driver of vegetation and treeline change during the Holocene. Early Holocene treeline was governed by moisture limitations, whereas late-Holocene treeline was sensitive to increases in growing season temperatures. Climate projections for the region suggest warmer temperatures could decrease effective growing season moisture at high elevations resulting in a reduction of treeline elevation.

Ice Patches and Obsidian Quarries: Integrating Research Through Collaborative Archaeology in Tahltan Territory

ABSTRACT This article presents the results of archaeological survey of ice patches in the vicinity of the vast obsidian quarries and artifact scatters found near Goat Mountain and the Kitsu Plateau in Mount Edziza Provincial Park, Tahltan Territory. During the survey, over 50 perishable artifacts were found, including stitched birch bark containers, wooden walking staffs, carved and beveled sticks, an atlatl dart foreshaft, and a stitched hide boot. Radiocarbon ages on 13 of the perishable artifacts reveal that they span the last 7000 years. These finds were made against a massive and stunning backdrop of scattered obsidian artifacts: bifaces, cores, flakes, and raw material nodules. This project collaborated with the Obsidian Discoveries Tahltan Tene Mehodihi Youth Group Hike and the “Our Ancestors’ Trail” museum exhibition. This collaboration resulted in connections between the archaeological results presented here, community learning, and artistic inspiration.

Robust vehicle lane keeping control with networked proactive adaptation

Road condition is an important environmental factor for autonomous vehicle control. A dramatic change in the road condition from the nominal status is a source of uncertainty that can lead to a system failure. Once the vehicle encounters an uncertain environment, such as hitting an ice patch, it is too late to reduce the speed, and the vehicle can lose control. To cope with unforeseen uncertainties in advance, we study a proactive robust adaptive control architecture for autonomous vehicles' lane-keeping control problems. In the proposed framework, the data center generates a prior environmental uncertainty estimate with a quantified uncertainty by combining weather forecasts and measurements from anonymous vehicles through a spatio-temporal filter. The prior estimate and quantified uncertainty contribute to designing a robust heading controller and nominal longitudinal velocity for proactive adaptation to each new abnormal condition. Then the control parameters are updated based on posterior information fusion with on-board measurements.

Callisto's Atmosphere: The Oxygen Enigma

AbstractObservations of Callisto's atmosphere have indicated an O2 component should exist, but the evolution from its initial source to its inferred steady‐state abundance is not well understood. Herein we constrain the production of O2 via radiolysis within Callisto's exposed ice patches and determine the corresponding O2 column density. To do so, for the first time we simulate the thermal and energetic components of the Jovian magnetospheric plasma irradiating Callisto's atmosphere and estimate energy deposited therein by the impinging charged particles along their trajectories to the surface. We then calculate O2 source fluxes corresponding to the energy of the impacting plasma fluxes, which is coupled with estimated atmospheric lifetimes to determine the steady‐state abundance of O2. Our results suggest that production of O2 via radiolysis within the exposed ice on Callisto's surface does not produce a sufficiently dense atmosphere relative to the column densities inferred from observations by about 2–3 orders of magnitude. To resolve this discrepancy between estimated and observed abundances, we provide the first estimates for other potential sources of atmospheric O2. We also make similar estimates for the production of H2 in Callisto's atmosphere relative to constraints provided in the literature, and the conclusion is the same: a sufficiently dense atmosphere is not produced. Thus, we have shown that a better understanding of the production and fate of radiolytic products in Callisto's regolith is required in order to place firmer constraints on the generation mechanisms of its atmosphere in preparation for future observations.

Black carbon concentrations and modeled smoke deposition fluxes to the bare-ice dark zone of the Greenland Ice Sheet

Abstract. Ice–albedo feedbacks in the ablation region of the Greenland Ice Sheet (GrIS) are difficult to constrain and model due, in part, to our limited understanding of the seasonal evolution of the bare-ice region. To help fill observational gaps, 13 surface samples were collected on the GrIS across the 2014 summer melt season from patches of snow and ice that were visibly light, medium, and dark colored. These samples were analyzed for their refractory black carbon (rBC) concentrations and size distributions with a single-particle soot photometer coupled to a characterized nebulizer. We present a size distribution of rBC in fresh snow on the GrIS and from the weathering crust in the bare-ice dark zone of the GrIS. The size distributions from the weathering crust samples appear unimodal and were overall smaller than the fresh snow sample, with a peak around 0.3 µm. The fresh snow sample contained very large rBC particles that had a pronounced bimodality in the peak size distributions, with peaks around 0.2 and 2 µm. rBC concentrations ranged from a minimum of 3 µg-rBC/L-H2O in light-colored patches at the beginning and end of the melt season to a maximum of 32 µg-rBC/L-H2O in a dark patch in early August. On average, the rBC concentrations were higher (20 ± 10 µg-rBC/L-H2O) in patches that were visibly dark, compared to medium patches (7 ± 2 µg-rBC/L-H2O) and light patches (4 ± 1 µg-rBC/L-H2O), suggesting that BC aggregation contributed to snow aging on the GrIS, and vice versa. Additionally, concentrations peaked in light and dark patches in early August, which is likely due to smoke transport from wildfires in northern Canada and Alaska, as supported by the Navy Aerosol Analysis and Prediction System (NAAPS) reanalysis model. According to the model output, 26 mg m−3 of biomass-burning-derived smoke was deposited between 1 April and 30 August, of which 85 % came from wet deposition, and 67 % was deposited during our sample collection time frame. The increase in the rBC concentration and size distributions immediately after the modeled smoke deposition fluxes suggest that biomass burning smoke is a source of BC to the dark zone of the GrIS. Thus, the role of BC in the seasonal evolution of the ice–albedo feedbacks should continue to be investigated in the weathering crust of the bare-ice zone of the GrIS.

Yukon ice patches: Bryophyte generation from ancient ice-entombed assemblages

ABSTRACT In Southwestern Yukon, ice patches have shown substantial retreat since the Little Ice Age (1600–1900 AD) in response to warming trends. These ice patches support unique alpine wetlands that have formed habitats for diverse flora and fauna over millennia. With ice retreat, pristine bryophyte populations are exposed beneath accumulated ancient dung. Given that bryophytes have been shown to survive extreme conditions including ice entombment and can regenerate from viable cells, emergent ice margin bryophyte and dung samples from the Granger and Gladstone ice patches were assayed for regrowth potential under growth chamber conditions. Diaspore (spore/fragment) generation of species found in the original subfossil material was indicated in 68 percent of assays, emphasizing the cyclical establishment of ancient ice patch vegetation. One of the oldest samples, dating 4036 calibrated years BP from the Gladstone ice patch margin, showed remarkable bryophyte generation from diaspores in dung. These Yukon ice patches form reservoirs of cryopreserved biota and have a critical role in maintaining alpine diversity, which provides summer refuge for caribou and other alpine fauna. Ice margin fluctuations, which bury and release populations through time, are part of a complex revegetation sequence in alpine regions that has followed deglaciation.

Mass-balance and ablation processes of a perennial polar ice patch on the northern coast of Ellesmere Island

AbstractIce patches have implications for landscape and ecosystem dynamics in polar deserts, however, the understanding of the driving factors that control their spatio-temporal variability is limited. This study aims to assess the seasonal and long-term evolution of ice patches on Ward Hunt Island (WHI; 83°N, Canadian High Arctic) based on field measurements of surface mass and energy balance. Results show that mass gains of the ice patch systems occur mostly through drifting snow, making them highly linked to the topography as well as the frequency and magnitude of wind events. Summer ablation is primarily driven by net radiation, but the short-term variability in melt rate is driven by sensible heat fluxes. The highest ablation rates occur during the passage of warm fronts that combine strong winds and mild temperatures. Conversely, foggy days reduce fluxes of solar radiation and sensible heat to the snow/ice surface, thereby suppressing ablation. Ice patches are less climate-sensitive than other cryospheric elements due to a feedback between snow accumulation and topography, however, summer ablation is strongly influenced by micrometeorology. Model projections of these factors suggest that conditions will become critical for preserving ice patches at WHI and along the northern coast of Ellesmere Island as early as in the next decades.

A Non-thermal De-icing Technique Using Ultrasonic Guided Waves

A non-thermal and low-cost ultrasonic de-icing method was applied in this study to solve the problem of ice accumulation on the surface of the structure. Numerical simulation analysis and an experimental test were conducted to confirm the feasibility of non-thermal de-icing. The shear stresses generated by a transducer at different installation locations were calculated in ANASYS simulation software to determine the optimal installation location and excitation frequency of the transducer. The de-icing experiment shows that the ice patch (60mm × 60mm × 4mm) was removed in less than ten seconds notwithstanding in a freezer at - 25 °C. The thermocouple temperature curve shows that the surface temperature of the plate is always below 0 °C. In other words, the icing is removed by force rather than thermal effects. The results of the ANSYS numerical simulation are consistent with those of the experiment, which indicates that the ANSYS numerical simulation provides a good reference for the de-icing experiment. Both the numerical simulation and the experiment confirm that non-thermal de-icing can be realized using a sandwich ultrasonic transducer.

Spatial characteristics of frazil streaks in the Terra Nova Bay Polynya from high-resolution visible satellite imagery

Abstract. Coastal polynyas around the Antarctic continent are regions of very strong ocean–atmosphere heat and moisture exchange that are important for local and regional weather, sea ice production, and water mass formation. Due to extreme atmospheric conditions (very strong offshore winds, low air temperature, as well as humidity) the surface ocean layer in polynyas is highly turbulent, with mixing due to combined Langmuir, wind-induced, and buoyancy-driven turbulence. One of the visible signs of complex interactions between the mixed-layer dynamics and the forming sea ice are frazil streaks, elongated patches of high ice concentration separated by areas of open water. In spite of their ubiquity, observational and modelling analyses of frazil streaks have been very limited largely due to the fact that their significance for heat flux and ice production is only just becoming apparent. In this study, the first comprehensive analysis of the spatial variability of surface frazil concentration is performed for the Terra Nova Bay Polynya (TNBP). Frazil streaks are identified in high-resolution (pixel size 10–15 m) visible satellite imagery, and their properties (surface area, width, spacing, and orientation) are linked to the meteorological forcing (wind speed and air temperature). This provides a simple statistical tool for estimating the extent and ice coverage of the region of high ice production under given meteorological conditions. It is also shown that the orientation of narrow streaks tends to agree with the wind direction, suggesting the dominating role of the local wind forcing in their formation. Very wide streaks, in turn, deviate from that pattern, as they are presumably influenced by several additional factors, including local water circulation and the associated convergence zones. An analysis of peak wavelengths and directions determined from the images, compared to analogous open-water wavelengths computed with a spectral wave model, demonstrates a significant slow-down in the observed wave growth in TNBP. This suggests an important role of frazil streaks in modifying wind-wave growth and/or dissipation in polynyas.

Deriving a year 2000 glacier inventory for New Zealand from the existing 2016 inventory

Abstract Due to adverse snow and cloud conditions, only a few inventories are available for the maritime glaciers in New Zealand. These are difficult to compare as different approaches and baseline data have been used to create them. In consequence, glacier fluctuations in New Zealand over the past two decades are only known for a few glaciers based on field observations. Here we present the results of a new inventory for the ‘year 2000’ (some scenes are from 2001 and 2002) that is based on glacier outlines from a recently published inventory for the year 2016 and allowed consistent change assessment for nearly 3000 glaciers over this period. The year 2000 inventory was created by manual on-screen digitizing using Landsat ETM+ satellite imagery (15 m panchromatic band) in the background and the year 2016 outlines as a starting point. Major challenges faced were late and early seasonal snow, clouds and shadow, the geo-location mismatch between Landsat and Sentinel-2 as well as the correct interpretation of ice patches and ice under debris cover. In total, we re-mapped 2967 glaciers covering an area of 885.5 km2 in 2000, which is 91.7 km2 (or 10.4%) more than the 793.8 km2 mapped in 2016. Area change rates (mean rate −0.65% a−1) increase towards smaller glaciers. Strongest area loss from 2000 to 2016 occurred at elevations ~1900 m but the highest relative loss was found below 800 m a.s.l. In total, 109 glaciers split into two or more entities and 264 had wasted away by 2016.

Ice Patch Archaeology in the Teton Mountains

Since 2015, I have investigated 21 ice patches in the Teton Range, Wyoming and located one pre-contact and several post-contact artifacts. The pre-contact artifact is a modified whitebark pine stick that dates to 3158 to 2960 cal BP. The post-contact artifacts are one 1940s wallet, one carved Boy Scout walking stick, and two modified pine sticks that date to the contact/post-contact periods. I also collected paleobiological specimens, including wood samples from dead trees and bison bones that are used to reconstruct past tree line elevations, as proxies for paleoclimate regimes, and to reconstruct the pre-contact lifeways of bison in the higher elevations of the Greater Yellowstone Area. This article presents the combined results of these investigations and their implications for future ice patch research in the Tetons.