Disappearance Of Ice Research Articles

Influence of early melting of the ice cover and high water level on functioning of the coastal rookery for baikal seal (<i>Pusa sibirica</i> Gm.) on Dolgiy Island (Lake Baikal), on materials of 2020

Functioning of a coastal seal rookery is considered on example of those located on Dolgiy Island in Lake Baikal, regularly visited by baikal seal <i>Pusa sibirica</i> Gm., which is constantly monitored by video surveillance. A case of the year 2020 with extremely early (comparing to 2011–2019) destruction and disappearance of ice in the northern part of the lake and rapid rise of the water level in summer-autumn is analyzed. Timing of the seals haul onshore and their abundance in rookery depend on the ice conditions: the lower ice cover – the earlier hauling-out and the higher abundance. Since the beginning of the rookery formation in May, up to 400 animals roosted there at the same time. Too early disappearance of the floating ice caused an abnormally large portion of individuals with incomplete molting on the rookery, and the delay in molting affected likely negatively on the animals health. Other negative factor was the deficit of available solid substrate for hauling-out because of rapid rise of the water level, particular in early summer. However, a large number of very well-fed adult females and males was observed on the rookery in May; presumably they did not participate in reproduction of population in 2020.

Using interferometric synthetic aperture rader (InSAR) analysis to detect ground deformation related to irreversibly changing ground ice, Mongolia

AbstractPermafrost in Mongolia shows highly heterogeneous features in space and the contents of ground ice are dependent on the local geographies such as topography, ground wetness, and vegetation cover. Recent permafrost degradation would cause thawing and disappearance of ground ice, destabilizing and subsiding the ground surface. This study aimed to detect topographic deformation related to irreversibly changing ground ice over the permafrost terrain of Mongolia. To end this we used interferometric synthetic aperture RADAR (InSAR) technique, which is capable to measure vertical ground deformation on a centimeter scale. Advanced land observing satellite‐based phased array type L‐band synthetic aperture radar (PALSAR) images (June to September 2007 to 2010) and PALSAR‐2 images (June to September 2014 to 2017) quantified near‐year‐round displacement of the ground surface. The overall deformation was in a range of −3 to 3 cm (subsidence and uplift, respectively) between the image interval and relatively high subsidence occurred during warm years. The areas experiencing consecutive uplift and subsidence correspond to ground underlain by ice‐rich soils, indicating the dominant roles of thawing and growing ground ice for local deformation over permafrost terrain. We discuss the relation of observed ground deformation trends with regional climate and local geohydrology that influence ground ice formation.

EXTENDED MOLTING AGAINST THE BACKGROUND OF CLIMATE WARMING IS THE MAIN REASON FOR THE EMERGENCE OF THE BAIKAL SEAL (<i>PUSA SIBIRICA</i>, PINNIPEDIA) TO COASTAL ROOKERIES

An analysis of the video films taken at a Baikal seal rookery in 2011–2021 on the Long Island, Ushkany Islands, northern Lake Baikal, showed that the total number and time of the emergence of animals on the shore were determined by the time of the disappearance of ice in the northern part of the lake. Yet, regardless of the ice regime, a significant part of the animals (up to 80%) leaving land continued molting. At the same time, the nature of molting (its topology) was disturbed in the vast majority of cases, molting being diffuse in character, often with elements of pathological manifestations. The number of molting individuals (in %) decreased by autumn, but still remained large, even though such dynamics were observed not every year. Incomplete molting did not interfere with animals’ fattening, as most seals were well or very well fed (especially by autumn), with individuals leaving the rookery immediately after the disappearance of ice also being well fat. At the same time, animals in coastal haulouts showed pathologies of the skin and hairline annually, the occurrence of which was probably associated, among other things, with abnormal molting. A large number of animals seem to leave for wintering with an incomplete molt, with their further fate being unknown. The data obtained indicate that disturbing the dormancy of molting seals on rookeries is inadmissible, since the excessive factor of disturbance (observed at the rookery at the present time) can play significant negative roles through affecting the physical condition (health) of animals.

Travel-time variability during the 2016–2017 deep-water Canada Basin Acoustic Propagation Experiment

The Arctic Ocean is undergoing dramatic changes in response to increasing atmospheric concentrations of greenhouse gases. The decreases in ice extent, the near disappearance of multiyear ice, and changes in the stratification of the ocean all have important implications for underwater acoustic propagation. During the 2016–2017 Canada Basin Acoustic Propagation Experiment (CANAPE), a long vertical receiving array was embedded within an ocean acoustic tomography array of six acoustic transceivers with a radius of 150 km. The impulse response of the ocean was measured every four hours using broadband signals centered at about 250 Hz. The observed travel-time variability was extraordinarily low, reflecting both the low internal-wave energy level and sparseness of mesoscale eddies in the Canada Basin. The peak-to-peak travel time variability of the early, resolved ray arrivals was only a few tens of milliseconds, and the standard deviations over the entire year were only a few milliseconds. The travel-time spectra show increasing energy at lower frequencies and enhanced semidiurnal variability, presumably due to some combination of the semidiurnal tides and inertial variability. The travel-time fluctuations are roughly an order of magnitude smaller than is typical in midlatitudes at similar ranges.

Regional impact of large-scale climate oscillations on ice out variability in New Brunswick and Maine.

The available ice out (the date of disappearance of ice from a water body) records were analyzed from four relatively closely spaced lakes in southwestern New Brunswick (Harvey, Oromocto, Skiff) and eastern Maine (West Grand Lake), with the longest set of available observations being for Oromocto Lake starting in 1876. Results of a coherence analysis carried out on the ice out data from the four lakes indicates that there is regional coherence and correspondingly, that regional drivers influence ice out. These results also indicate that ice out dates for lakes from the region where records have not been kept can also be interpolated from these results. As the ice out record was coherent, further analysis was done for only Oromocto Lake on the basis of it having the longest ice out record. Cross-wavelet analysis was carried out between the ice out record and a variety of cyclic climate teleconnections and the sunspot record to identify which phenomena best explain the observed ice out trends. The most important observed contributors to ice out were the North Atlantic Oscillation (NAO) and the El Niño Southern Oscillation (ENSO), with observed periodicities at the interannual scale. At the decadal scale the Pacific Decadal Oscillation (PDO) and the 11-year solar cycle were the only patterns observed to significantly contribute to ice out.

The surface geology of the Prince Edward Islands: refined spatial data and call for geoconservation

Abstract Volcanological maps of the sub-Antarctic Prince Edward Islands were first published in 1968, with a revised surface geology map of Marion Island produced in 2006. These maps have been widely used in terrestrial studies on the Prince Edward Islands but they have limitations in spatial accuracy and detail. Using high-resolution satellite imagery and digital elevation data, more spatially accurate data for both Prince Edward and Marion Island’s surface geology are presented here. In particular, Marion Island’s volcanology on the western coast, including the 1980s lava flow, and the newly exposed Central Highland following the disappearance of extensive ice and snow cover is mapped with greater detail and verified through field observations. The spatial data are downloadable as ESRI layer packages, which can assist in future investigations of island biotic-abiotic processes and interactions and enable improvements in spatial modelling. In addition, this paper highlights geological features and specimens from the Prince Edward Islands as unique examples of geodiversity in a South African context. An overview of these features are provided in terms of their geoheritage value to enable a more comprehensive geoconservation strategy be incorporated into the Prince Edward Islands Management Plan.

Postglacial paleoceanography of the western Barents Sea: Implications for alkenone-based sea surface temperatures and primary productivity

The increasing influence of Atlantic Water (AW) in the Barents Sea, a process known as “Atlantification”, is gradually decreasing sea ice cover in the region. Ongoing global climate warming is likely to be one of its drivers, but to further understand the role of natural variability and the biogeochemical impacts of the inflow of AW into the western Barents Sea, we reconstructed sea surface temperatures (SSTs) and primary productivity in Storfjordrenna, a climatically sensitive area south of Spitsbergen, between approximately 13,950 cal yr BP and 1300 cal yr BP. The alkenone U37K* proxy has been applied to reconstruct SSTs, and the alkenone accumulation rate in marine sediments has been used to infer changes in primary productivity. Our data show that the SST increase was concomitant with the progressive loss of sea ice cover and an increase in primary productivity in the western Barents Sea. We interpret these changes as reflecting the increasing influence of AW in the area as the ice sheets retreated in Svalbard. The transition from the Arctic to the Atlantic domain first occurred after 11,500 cal yr BP, as the Arctic Front moved eastward of the study site but with considerable variability in surface ocean conditions. High SSTs at approximately 6400 cal yr BP may have led to limited winter surface cooling, likely inhibiting convective mixing and the return of nutrients to the euphotic zone and/or enhanced organic matter consumption by zooplankton due to an earlier light signal in the ice-free Storfjordrenna. During the late Holocene (3600-1300 cal yr BP), low insolation facilitated sea ice formation and thus brine production. The former may have launched convective water mixing and increased nutrient resupply to the sea surface, consequently enhancing primary productivity in Storfjordrenna. We propose that, on the basis of the paleoceanographic evidence, the modern increasing inflow of warm AW and the disappearance of pack ice on the Eurasian continental shelf are likely to weaken convective water mixing and decrease primary production in the region.

Interannual variability of the ice-free period duration in the southwestern Kara Sea

In the coming years, exploration drilling in the geological structures in the Kara Sea is planned. It will be carried out during the ice-free period using floating drilling facilities of a different ice class. The aim of the work is analysis of the interannual variability of duration of the ice-free period in the area of the geological structures the results of which are necessary for planning operational activity of the drilling platforms and optimization of expenses for exploration drilling on the Arctic shelf. For an assessment of interannual variability of the ice-free period duration in the area of the geological structures there were used data on the dates of water area clearance from ice and beginning of ice formation in the southwestern part of the Kara Sea for the period of 30 years on the basis of the AARI weekly ice charts. An analysis of interannual variability of the ice-free period duration showed that a 20-year summer (1989–2008) and a 10-year (2009–2018) intervals could be identified. It is shown that in the last decade as a result of combination of favorable hydrometeorological conditions the ice-free period duration has increased by more than 1 month. An analysis of the main hydrometeorological factors determining the ice-free period duration indicated that it is possible to perform an assessment of duration of exploration drilling operations in the water area of the East-Prinovozemelsky license blocks with a period in advance of several months. Drilling with the use of ice-resistant drilling platform allows us to extend the operation period, as drilling could be started after disappearance of close ice and finished after the ice thickness growth up to 30 cm.

Sand drift events and surface winds in south-central Sweden: From the deglaciation to the present

During the transition from the last glacial into the Holocene interglacial, the atmospheric circulation in the North Atlantic area changed from a glacial mode, influenced by the presence of large ice sheets, into a system more similar to that of the present day. This change had implications for wind, temperature and precipitation patterns that can be traced in geological archives. Here, we focus on reconstructing past wind directions over southern Scandinavia, as inferred from the net sediment transport direction of inland dunes in south-central Sweden. We analysed single dunes and dune fields along a 540-km-long S-N transect with LiDAR (Light detection and ranging) derived DEMs (digital elevation models) to determine their geomorphological type and the directional mode of the wind that led to their formation. Luminescence ages of sand drift and dune formation were compiled from previous studies, allowing us to build a chronology of sand drift after the deglaciation of south-central Sweden. The majority of the dunes appear to have been formed by westerly or northwesterly winds and stabilised ∼10.5–9.0 ka. Although this is rather close in time to the local deglaciation for the northern sites, it is long after the disappearance of ice from the more southern sites. The coeval dune stabilisation over such a large geographical area suggests that regional environmental conditions played an important role. It is likely that an unstable climate in conjunction with low groundwater tables during the early Holocene locally delayed vegetation from stabilising the dunes.

Publisher Correction: Doping-induced disappearance of ice II from water’s phase diagram

In the version of this Letter originally published, the citation to ref. 30 in the Fig. 1 caption should have been to ref. 29, and the citation to ref. 29 in the Methods should have been to ref. 30.

Doping-induced disappearance of ice II from water’s phase diagram

Water and the many phases of ice display a plethora of complex physical properties and phase relationships1–4 that are of paramount importance in a range of settings including processes in Earth’s hydrosphere, the geology of icy moons, industry and even the evolution of life. Well-known examples include the unusual behaviour of supercooled water 2 , the emergent ferroelectric ordering in ice films 4 and the fact that the ‘ordinary’ ice Ih floats on water. We report the intriguing observation that ice II, one of the high-pressure phases of ice, disappears in a selective fashion from water’s phase diagram following the addition of small amounts of ammonium fluoride. This finding exposes the strict topologically constrained nature of the ice II hydrogen-bond network, which is not found for the competing phases. In analogy to the behaviour of frustrated magnets 5 , the presence of the exceptional ice II is argued to have a wider impact on water’s phase diagram, potentially explaining its general tendency to display anomalous behaviour. Furthermore, the impurity-induced disappearance of ice II raises the prospect that specific dopants may not only be able to suppress certain phases but also induce the formation of new phases of ice in future studies.

A New Ocean: The Legal Challenges of the Arctic Thaw

Arctic warming poses considerable legal challenges to the region. The fast disappearance of polar ice will increase economic activity, destabilize the environment, and create a host of security issues. Previous discussions have tended to focus on one of these facets in isolation. This Article aims instead to provide the reader with a comprehensive, up-to-date picture of the Arctic region’s legal needs. The Article first addresses navigation and natural resource disputes arising from the expected increase in Arctic shipping and hydrocarbon exploitation. It then examines the pollution and conservation challenges this increase in human activity will bring. Finally, it analyzes the human security, law enforcement, and military security issues brought about by the Arctic thaw. The Article concludes by critically evaluating the international community’s current institutional responses to Arctic warming and considering possible measures to address current response gaps, including the possibility of a holistic treaty.

The seeding of ice algal blooms in Arctic pack ice: The multiyear ice seed repository hypothesis

During the Norwegian young sea ICE expedition (N-ICE2015) from January to June 2015 the pack ice in the Arctic Ocean north of Svalbard was studied during four drifts between 83° and 80° N. This pack ice consisted of a mix of second-year, first-year and young ice. The physical properties and ice algal community composition was investigated in the three different ice types during the winter-spring-summer transition. Our results indicate that algae remaining in sea ice that survived the summer melt season are subsequently trapped in the upper layers of the ice column during winter and may function as an algal seed repository. Once the connectivity in the entire ice column is established, as a result of temperature-driven increase in ice porosity during spring, algae in the upper parts of the ice are able to migrate towards the bottom and initiate the ice-algal spring bloom. Furthermore, this algal repository might seed the bloom in younger ice formed in adjacent leads. This mechanism was studied in detail for the often dominating ice diatom Nitzschia frigida.The proposed seeding mechanism may be compromised due to the disappearance of older ice in the anticipated regime shift towards a seasonally ice-free Arctic Ocean.

GLOBAL CHANGES IN THE SEA ICE COVER AND ASSOCIATED SURFACE TEMPERATURE CHANGES

The trends in the sea ice cover in the two hemispheres have been observed to be asymmetric with the rate of change in the Arctic being negative at −3.8 % per decade while that of the Antarctic is positive at 1.7 % per decade. These observations are confirmed in this study through analyses of a more robust data set that has been enhanced for better consistency and updated for improved statistics. With reports of anthropogenic global warming such phenomenon appears physically counter intuitive but trend studies of surface temperature over the same time period show the occurrence of a similar asymmetry. Satellite surface temperature data show that while global warming is strong and dominant in the Arctic, it is relatively minor in the Antarctic with the trends in sea ice covered areas and surrounding ice free regions observed to be even negative. A strong correlation of ice extent with surface temperature is observed, especially during the growth season, and the observed trends in the sea ice cover are coherent with the trends in surface temperature. The trend of global averages of the ice cover is negative but modest and is consistent and compatible with the positive but modest trend in global surface temperature. A continuation of the trend would mean the disappearance of summer ice by the end of the century but modelling projections indicate that the summer ice could be salvaged if anthropogenic greenhouse gases in the atmosphere are kept constant at the current level.

GLOBAL CHANGES IN THE SEA ICE COVER AND ASSOCIATED SURFACE TEMPERATURE CHANGES

Abstract. The trends in the sea ice cover in the two hemispheres have been observed to be asymmetric with the rate of change in the Arctic being negative at −3.8 % per decade while that of the Antarctic is positive at 1.7 % per decade. These observations are confirmed in this study through analyses of a more robust data set that has been enhanced for better consistency and updated for improved statistics. With reports of anthropogenic global warming such phenomenon appears physically counter intuitive but trend studies of surface temperature over the same time period show the occurrence of a similar asymmetry. Satellite surface temperature data show that while global warming is strong and dominant in the Arctic, it is relatively minor in the Antarctic with the trends in sea ice covered areas and surrounding ice free regions observed to be even negative. A strong correlation of ice extent with surface temperature is observed, especially during the growth season, and the observed trends in the sea ice cover are coherent with the trends in surface temperature. The trend of global averages of the ice cover is negative but modest and is consistent and compatible with the positive but modest trend in global surface temperature. A continuation of the trend would mean the disappearance of summer ice by the end of the century but modelling projections indicate that the summer ice could be salvaged if anthropogenic greenhouse gases in the atmosphere are kept constant at the current level.

Scottish early Holocene vegetation dynamics based on pollen and tephra records from Inverlair and Loch Etteridge, Inverness-shire

This paper presents the results of an investigation of early Holocene cryptotephra layers recovered from sediments in two kettle-hole basins at Inverlair (Glen Spean) and Loch Etteridge (Glen Fernisdale). Electron probe micro-analysis (EPMA) of shards from two cryptotephra layers revealed that the uppermost layer in both sequences has a composition similar to the An Druim tephra, first reported from a site in Northern Scotland. We present evidence that distinguishes the An Druim from the chemically very similar early Holocene Ashik tephra. The lowermost layer at Inverlair matches the composition of the Askja-S tephra found in the Faroe Islands, Ireland, Sweden, Germany and Switzerland. This is the first published record of the Askja-S tephra from mainland Scotland. As at other sites, the Askja-S seems to mark a short-lived climatic deterioration, most likely the Pre-Boreal Oscillation: at Inverlair it occurs just above an oscillation represented by a reduction in LOI values and in the abundance of Betula pollen, and by a peak in Juniperus pollen. The lowermost layer at Loch Etteridge has a Katla-type chemistry and extends through the upper part of the Loch Lomond (Younger Dryas/GS-1) Stadial to the Stadial/Holocene transition; it may represent a composite layer which merges the Vedde and Abernethy tephras. One of the key conclusions is that the glacial-melt deposits in the vicinity of Inverlair (kames and kame terraces) were ice-free by c. 10.83ka (the age of the Askja-S), providing a limiting age on the disappearance of LLR ice in Glen Spean.

Changes in ice phenology on polish lakes from 1961 to 2010 related to location and morphometry

Observations of lake ice at the shore, complete ice cover, ice duration, ice thickness and other measures for 18 Polish lakes were collected for the 50 year period (1961–2010). Average ice dates in early winter became later: first appearance of ice along shore 2.3 days decade −1 and complete ice cover 1.2 days decade −1 while complete ice cover disappeared earlier (5.6 days decade −1 ) as did last ice at the shore (4.3 days decade −1 ). The duration of ice cover decreased by 5.6 days decade −1 and average ice thickness declined by 6.1 cm decade −1 . The magnitude of these values for individual lakes decreased from eastern to western Poland. This geographic gradient is likely related to regional atmospheric circulation because in winter this part of Europe is strongly affected by continental air, an influence that is greater in the east. A multivariate redundancy analysis (RDA), used in order to examine the dependence of ice measures on lake physical properties and location, indicated longitude and altitude as key factors explaining lake ice dynamics such as the disappearance of ice and ice cover, ice cover duration and thickness. Lake volume and average depth influenced mostly the appearance of ice and ice cover.

Enhanced ferromagnetism and emergence of spin-glass-like transition in pyrochlore compound Dy2Ti2−xVxO7

We have studied the magnetic properties of spin-frustrated compound Dy2Ti2−xVxO7 single crystals. Bulk magnetization data show that ferromagnetic interaction enhances with increasing content of V, resulting from the ferromagnetic interactions between Dy and V ions. It is also found from ac susceptibility that the modestly doped samples (x≤0.4) still keep ice state, demonstrating the robustness of spin ice. When the doped concentration increases up to 0.5, more disorder on B site and internal field associated with V4+ ions would affect the macroscopic ground-state degeneracy and relieve the frustration, leading to the disappearance of spin ice and occurrence of a spin-glass-like transition. The magnetic properties of the system are related to magnetic frustration and local structural disorder.

Rapid disappearance of perennial ice on Canada's most northern lake

AbstractField records, aerial photographs, and satellite imagery show that the perennial ice cover on Ward Hunt Lake at Canada's northern coast experienced rapid contraction and thinning after at least 50 years of relative stability. On all dates of sampling from 1953 to 2007, 3.5 to 4.3 m of perennial ice covered 65–85% of the lake surface in summer. The ice cover thinned from 2008 onward, and the lake became ice free in 2011, an event followed by 26 days of open water conditions in 2012. This rapid ice loss corresponded to a significant increase in melting degree days (MDD), from a mean (±SD) of 80.4 (±36.5) MDD (1996–2007) to 136.2 (±16.4) MDD (2008–2012). The shallow bathymetry combined with heat advection by warm inflows caused feedback effects that accelerated the ice decay. These observations show how changes across a critical threshold can result in the rapid disappearance of thick perennial ice.

Ernest Hemingway’s Description of the Mountaintop in “The Snows of Kilimanjaro” and Climate Change Research

The ice field of Mount Kilimanjaro, the highest peak of Africa, was made famous by Ernest Hemingway in “The Snows of Kilimanjaro.” Scientific evidence shows that the snows of Kilimanjaro are vanishing. When first reports of this meltdown linked it to global warming, natural scientists evoked the Hemingway story to reinforce the alarming message of the human-made climate change. Recent scientific observations suggest, however, that the disappearance of Kilimanjaro ice originates from hydroclimatic change rather than direct effects of global warming. Mount Kilimanjaro has thus become an icon of controversial climate change debates.