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38 results on '"glacial ice"'

1. New Data on Deuterium Excess Values of Glacial Ice in Kamchatka Peninsula.

Author

Chizhova, Yu. N., Mikhalenko, V. N., Korneva, I. A., Muravyov, Ya. D., Hayredinova, A. G., and Vorobiev, M. A.

Subjects
*GLACIERS, *ICE cores, *CLIMATE change, *ISOTOPIC signatures, *PENINSULAS, *DEUTERIUM, *OXYGEN isotopes, *NEUTRINOLESS double beta decay
Abstract

The isotopic signature (δ18О, δ2Н, d-excess) of the glacier ice in Ushkovskii volcano (Kamchatka Peninsula) was studied. A new shallow ice core was obtained in 2022 in the Gorshkov crater. The 14 m long ice core was dated by counting the annual layers, which were also compared with known eruptions in recent years. The upper 14 m of the glacier were formed over the last 16 years (from 2006 to 2022). The values of δ18О vary from −16 to −24‰, and the values of δ2Н, from −110.5 to −177.7‰, while the mean values are −20.5 and −150.2‰, respectively. The d-excess values vary with depth from 8.7 to 21.3‰ at a mean value of 13.7‰. For winter horizons at low values of δ18О and δ2Н, an increase in d-excess is noted. Such features are associated with the origin of moisture brought to Kamchatka. The source of moisture is the Pacific Ocean, the Sea of Okhotsk, and the Sea of Japan, for which there are pronounced differences in the conditions of moisture evaporation between summer and winter. The trends of increases in the δ18О and δ2Н values from 2006 to 2022 are accompanied by a decrease in the deuterium excess, indicating an increase in summer precipitation. However, in addition to changes in the seasonal proportions of precipitation, the d-excess values of ice may reflect climatic changes in the source of moisture. [ABSTRACT FROM AUTHOR]

Published
2024
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2. SEPARACIÓN DE PARTÍCULAS INCLUIDAS EN HIELOS NATURALES POR SUBLIMACIÓN ADAPTADA

Author

L. E. Arena

Subjects
hail, permafrost, glacial ice, sublimation, sem and clsm microscopy, Physics, QC1-999
Abstract

Non-soluble particles trapped in natural ice (glaciers, permafrost, hail) provide valuable information about the environments in which they were formed. The extraction of the particles is usually carried out through the melting of ice and subsequent filtering of the water obtained. Here, a novel methodology for extracting ice particles from the solid-phase is presented, which is efficient, low-cost in infrastructure, and minimizes possible sources of contamination. This methodology of adapted sublimation particle separation allows to determine the spatial distribution and concentration of non-soluble particles, as well as their sizes (without the limitations of filtration), their shape, structure and elementalchemical composition. The method is in this case applied to hail collected during the program COSECHEROS, which has a medium-sized particle of 40μm at its center.

Published
2024
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3. Understanding Fungi in Glacial and Hypersaline Environments.

Author

Gostinčar, Cene and Gunde-Cimerman, Nina

Abstract

Hypersaline waters and glacial ice are inhospitable environments that have low water activity and high concentrations of osmolytes. They are inhabited by diverse microbial communities, of which extremotolerant and extremophilic fungi are essential components. Some fungi are specialized in only one of these two environments and can thrive in conditions that are lethal to most other life-forms. Others are generalists, highly adaptable species that occur in both environments and tolerate a wide range of extremes. Both groups efficiently balance cellular osmotic pressure and ion concentration, stabilize cell membranes, remodel cell walls, and neutralize intracellular oxidative stress. Some species use unusual reproductive strategies. Further investigation of these adaptations with new methods and carefully designed experiments under ecologically relevant conditions will help predict the role of fungi in hypersaline and glacial environments affected by climate change, decipher their stress resistance mechanisms and exploit their biotechnological potential. [ABSTRACT FROM AUTHOR]

Published
2023
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4. Characteristics of Chemical Solutes and Mineral Dust in Ice of the Ablation Area of a Glacier in Tien Shan Mountains, Central Asia

Author

Yunjie Chen, Nozomu Takeuchi, Feiteng Wang, and Zhongqin Li

Subjects
glacial ice, ice core, supraglacial environments, mineral dust, soluble ions, outcropping flux, Science
Abstract

Diverse microbial communities live on glacial surfaces, with abundances and diversities dictated by the chemical and physical conditions of the supraglacial environment. Chemical solutes and mineral dust on glacial surfaces are generally derived from the atmosphere as aerosols, but they can also be supplied from glacial ice. In this study, a 56-m ice core from the ablation area of a mountain glacier in the Tien Shan Mountains of Central Asia was analyzed to characterize the chemical solutes and mineral dust in glacial ice. Soluble chemical ion and mineral dust analysis in the ice core showed that their concentrations varied with depth. The most dominant ion was Ca2+ (mean: 79.8 μEq L−1), followed by Cl−, SO42-, NH4+, and NO3−. The mean dust concentration in the glacial ice was 2.5 ×105 number ml−1. Chemical solute and mineral dust concentrations in the samples indicate that melting glacial ice could potentially affect supraglacial conditions. The annual fluxes of the major ions outcropping from glacial ice were estimated based on their concentrations and the observed melt rate of the ice surface. Consequently, they were comparable to or higher than those from the atmosphere. The mean mass flux of mineral dust from glacial ice was greater than that from the atmosphere. Our results showed that glacial ice supplies chemical solutes and mineral dust to the supraglacial environment and that changing melting rates of glacial ice would affect the chemical conditions on the glacier surface and the growth of photoautotrophs on the ablating ice surface.

Published
2022
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6. Revisiting Glacier Dynamics for Stationary Approximation of Plane-Parallel Creeping Flow.

Author

Ershkov, Sergey and Leshchenko, Dmytro

Subjects
GLACIERS, CRAWLING & creeping, PSYCHOLOGICAL stress, ICE sheets, CLASSICAL mechanics
Abstract

We have presented in this analytical research the revisiting of approach for mathematical modeling the Glacier dynamics in terms of viscous-plastic theory of 2-dimensional movements within (x, y)-plane in cartesian coordinates. The stationary creeping approximation for the plane-parallel flow of slowly moving glacial ice on absolutely flat surface without any inclination has been considered. Even in such simple formulation, equations of motion that governs by the dynamics of viscous-plastic flow of glacial ice is hard to be solved analytically. We have succeeded in obtaining analytical expression for the components of velocity in Ox-direction of motion for slowly moving glacial ice (Ox-axis coincides to the initial main direction of slowly moving glacial ice). Restrictions on the form of flow stem from the continuity equation as well as from the special condition for non-Newtonian (viscous-plastic) flow have been used insofar. [ABSTRACT FROM AUTHOR]

Published
2021
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7. Perspectives for using glacial and periglacial microorganisms for plant growth promotion at low temperatures.

Author

Yarzábal, Luis Andrés

Subjects
*MICROBIAL growth, *LOW temperatures, *EXTREME environments, *FERTILIZERS, *BIOLOGICAL pest control agents, *PLANT development, *PLANT growth
Abstract

Even though they are among the most extreme environments in which life can develop, glaciers are colonized by metabolically active microbes, some of which thrive—in their own particular way—under the prevailing harsh conditions. Glacial or periglacial microbes are often psychrophiles since they are able to grow optimally at low temperatures. This ability has evolved through a series of adaptations, both molecular and physiological, some of which have been exploited by the biotechnological industry to develop useful products and processes. The recent discovery of cold-adapted plant growth-promoting microorganisms (PGPM) in glacial ice or periglacial soils has opened a gate to a new trove of applications due to their potential use as biofertilizers or biocontrol agents, effective in cold climates. It has been claimed that this would be of profit to increase agriculture productivity in hilly terrains, like those prevailing in the Andes or the Himalayas, since—in addition to their ability to promote plant growth through direct or indirect mechanisms—they represent an environmentally friendly alternative to the use of pesticides and chemical fertilizers. In the following chapter, I summarize the current knowledge on the identity and characteristics of such PGPM and highlight the experiences in promoting the growth of a few plant species, at low temperatures. Key Points •Countless microbes are immured in glaciers and their surroundings. •Many glacial and periglacial microbes are cold-loving (i.e., psychrophiles). •Some glacial and periglacial psychrophiles promote plant growth and development. •Plant growth-promoting psychrophiles can be used to develop biofertilizers. [ABSTRACT FROM AUTHOR]

Published
2020
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8. Spatio‐temporal analysis of glacial ice area distribution of Hunza River Basin, Karakoram region of Pakistan.

Author

Baig, Siddique Ullah, Khan, Humaira, and Din, Ahmad

Subjects
SPATIOTEMPORAL processes, ICE sheets, WATERSHEDS, GLACIERS, CLIMATE change
Abstract

Abstract: There is a high degree of uncertainty about the state and fate of Pakistan's Karakoram glaciers due to data scarcity in high altitude regions. They are thought to be less vulnerable to climatic change because they behave differently as compared with eastern Himalayas. This study measures the decadal temporal changes in the glacial ice area of Karakoram's Hunza River Basin, one of the eight subbasins of Upper Indus Basin. An attempt has been made to investigate the relationship between glacial ice area changes and calculated values of precipitation, temperature and run‐off. A combination of satellite and field‐based approach is applied. Output includes maps of glacial ice hypsometries of eight glacial ice subregions of Hunza River Basin for 3 years (i.e., 1989, 2002, and 2010). The results show a decreasing trend in the glacial ice‐covered area signifying a reduction of 20.47% with the largest reduction being in the lower elevation bands. There is presently no conclusive answer as to why glacial ice in the Karakoram is acting differently from the near‐global indication of glacial ice changes. Climate data from high altitudes are needed to find answer for this anomalous behaviour. [ABSTRACT FROM AUTHOR]

Published
2018
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9. Sidestep Capability for Platforms in Arctic Using Steel Lazy Wave Riser Configuration.

Author

Felisita, Airindy, Karunakaran, D., Gudmestad, O. T., and Martinsen, Lars Olav

Abstract

This paper introduces a potential novel concept for glacial ice management. The concept involves the capability of a platform and its riser and mooring systems to shift for a relatively large distance- hence the 'sidestep' term-in order to bypass the glacial ice. However, in order for the platform to be able to sidestep, the platform needs to be equipped with features which support the large distance movement. For floating platforms like semi-submersibles, the sidestep movement may be accomplished by varying the tension rate of the mooring system to make it more slack or taut. However, a turret-moored FPSO needs to have a larger thruster capability, since the sidestep movement will be executed by the use of thrusters. This sidestep capability can be used as an additional safety measure for floaters operating in deep-water regions, which are susceptible to glacial ice. In particular for a turret-moored FPSO, this capability may be beneficial as an option prior to the turret disconnection. For this concept, the configuration of risers and mooring system should be carefully designed to withstand the shilling conditions, as the riser and mooring system will still be attached to the platform during the sidestep process. A steel riser in a lazy wave configuration (SLWR) is proposed to fulfill this requirement. This paper discusses the benefits and challenges of the sidestep concept. This paper also presents the analysis results of a lazy wave riser during the sidestep condition. Analysis works are carried out using the OrcaFlex simulation program. [ABSTRACT FROM AUTHOR]

Published
2016

10. Microbial Analyses of Ancient Ice Core Sections from Greenland and Antarctica

Author

Scott O. Rogers, Tom D'Elia, Ram Veerapaneni, and Caitlin Knowlton

Subjects
glacial ice, microbes, bacteria, fungi, Greenland, Antarctica, metagenomic, metatranscriptomic, cultures, Biology (General), QH301-705.5
Abstract

Ice deposited in Greenland and Antarctica entraps viable and nonviable microbes, as well as biomolecules, that become temporal atmospheric records. Five sections (estimated to be 500, 10,500, 57,000, 105,000 and 157,000 years before present, ybp) from the GISP2D (Greenland) ice core, three sections (500, 30,000 and 70,000 ybp) from the Byrd ice core, and four sections from the Vostok 5G (Antarctica) ice core (10,500, 57,000, 105,000 and 105,000 ybp) were studied by scanning electron microscopy, cultivation and rRNA gene sequencing. Bacterial and fungal isolates were recovered from 10 of the 12 sections. The highest numbers of isolates were found in ice core sections that were deposited during times of low atmospheric CO2, low global temperatures and low levels of atmospheric dust. Two of the sections (GISP2D at 10,500 and 157,000 ybp) also were examined using metagenomic/metatranscriptomic methods. These results indicated that sequences from microbes common to arid and saline soils were deposited in the ice during a time of low temperature, low atmospheric CO2 and high dust levels. Members of Firmicutes and Cyanobacteria were the most prevalent bacteria, while Rhodotorula species were the most common eukaryotic representatives. Isolates of Bacillus, Rhodotorula, Alternaria and members of the Davidiellaceae were isolated from both Greenland and Antarctica sections of the same age, although the sequences differed between the two polar regions.

Published
2013
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11. Microbial community changes along the Ecology Glacier ablation zone (King George Island, Antarctica).

Author

Grzesiak, Jakub, Zdanowski, Marek, Górniak, Dorota, Świątecki, Aleksander, Aleksandrzak-Piekarczyk, Tamara, Szatraj, Katarzyna, Sasin-Kurowska, Joanna, and Nieckarz, Marta

Subjects
MICROBIAL ecology, HABITATS, GEL electrophoresis, CRYOCONITE, SEDIMENTS
Abstract

In recent years, glacial surfaces have received much attention as microbial habitats of diverse photoautotrophic and heterotrophic cells. Supraglacial ecosystems are annually covered and uncovered by snow. The aim of this study is to investigate the microbial community response to changing environmental conditions in a transect following the receding snow line on the surface of Ecology Glacier (King George Island, Antarctica). Parameters of surface ice and cryoconite holes included chemical composition of ice and sediment, Bacteria diversity by denaturating gradient gel electrophoresis, microbial functional diversity (Biolog Ecoplates), and microbial counts (epifluorescence microscopy, colony-forming units). Data demonstrated profound differences between surface ice and cryoconite holes. Changing environmental factors along the transect influenced composition and abundance of the microbiocenosis in both habitat types. Several parameters correlated positively with distance from the glacier edge, including the cell morphotype Shannon index, chlorophyll a, nitrogen, and seston concentrations. Suspended solid content positively correlated with microbial abundance and diversity. Nitrogen and phosphorus were limiting factors of microbial growth as amounts of organic nitrogen and phosphorus positively correlated with the cell numbers, fission rates, and photoautotroph contribution. Our findings indicate that microbial community shows a response in terms of abundance and diversity to exposure of the glacial surface as snow-cover melts. To our knowledge, this is the first study to recognize a microbial development pattern on a glacier surface in connection with the receding snow line. This may help better understand variability within supraglacial habitats, correct sampling procedures, and inform biocenotic development models. [ABSTRACT FROM AUTHOR]

Published
2015
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12. Direct evidence for thinning and retreat of the southernmost Greenland ice sheet during the Younger Dryas

Author

Emily Gusterson, Klaus M. Wilcken, Dylan H. Rood, Yarrow Axford, Alberto V. Reyes, and Anders E. Carlson

Subjects
SHELF, 010506 paleontology, Archeology, 010504 meteorology & atmospheric sciences, Greenland, 04 Earth Sciences, Greenland ice sheet, 01 natural sciences, Glaciation, Ice core, Paleoclimatology, Deglaciation, Younger Dryas, Geosciences, Multidisciplinary, Ecology, Evolution, Behavior and Systematics, Holocene, 0105 earth and related environmental sciences, SOUTH, Global and Planetary Change, geography, geography.geographical_feature_category, Science & Technology, Cosmogenic isotopes, Paleontology, Geology, DEGLACIATION, NORTH-ATLANTIC, Pleistocene, CLIMATE, BE-10, Geography, Physical, Physical Geography, 13. Climate action, 21 History and Archaeology, Physical Sciences, Abrupt climate change, Physical geography, Ice sheet, GLACIAL ICE
Abstract

During the last deglaciation, North Atlantic climate abruptly warmed at the Bolling (∼14.7 ka), cooled into the Younger Dryas (∼12.9 ka) and abruptly warmed again into the Holocene (∼11.7 ka). While these events are defined by Greenland ice cores, there is still considerable uncertainty on Greenland ice-sheet margin responses to abrupt climate change. To refine the ice sheet's deglacial history, we present new cosmogenic nuclide surface exposure ages from boulders on bedrock at five sites in southernmost Greenland fjords located midway between the coast and inland ice margin. We find ice-sheet thinning below three local topographic highs at 12.7 ± 0.3 ka (n = 3), 13.1 ± 0.4 ka (n = 1, 2 outliers), and 12.3 ± 0.2 ka (n = 3), with up-fjord retreat at 12.5 ± 0.3 ka (n = 3) and 12.7 ± 0.2 ka (n = 4) based on two sites just above the mid-fjord marine limit. These mid-fjord 10Be ages therefore show southernmost Greenland ice-sheet thinning and retreat during the Younger Dryas. We hypothesize that this thinning and retreat was a response to ocean warming prior to the Holocene and/or summer shortwave radiative forcing during the Younger Dryas due to peak boreal summer insolation. Our results also support a previously hypothesized winter bias in proxy records of Younger Dryas atmospheric cooling, since a large summer cooling during the Younger Dryas could have counteracted the effects of ocean warming and direct radiative forcing, inhibiting ice-sheet retreat.

Published
2021

13. Microbial community development on the surface of Hans and Werenskiold Glaciers (Svalbard, Arctic): a comparison.

Author

Grzesiak, Jakub, Górniak, Dorota, Świątecki, Aleksander, Aleksandrzak-Piekarczyk, Tamara, Szatraj, Katarzyna, and Zdanowski, Marek

Subjects
*MICROBIAL development, *GLACIERS, *CRYOCONITE, *MICROBIAL diversity, *TUNDRA ecology, *BIRD nests, *ATMOSPHERIC aerosols
Abstract

Surface ice and cryoconite holes of two types of polythermal Svalbard Glaciers (Hans Glacier-grounded tidewater glacier and Werenskiold Glacier-land-based valley glacier) were investigated in terms of chemical composition, microbial abundance and diversity. Gathered data served to describe supraglacial habitats and to compare microbe-environment interactions on those different type glaciers. Hans Glacier samples displayed elevated nutrient levels (DOC, nitrogen and seston) compared to Werenskiold Glacier. Adjacent tundra formations, bird nesting sites and marine aerosol were candidates for allochtonic enrichment sources. Microbial numbers were comparable on both glaciers, with surface ice containing cells in the range of 10 mL and cryoconite sediment 10 g dry weight. Denaturating gradient gel electrophoresis band-based clustering revealed differences between glaciers in terms of dominant bacterial taxa structure. Microbial community on Werenskiold Glacier benefited from the snow-released substances. On Hans Glacier, this effect was not as pronounced, affecting mainly the photoautotrophs. Over-fertilization of Hans Glacier surface was proposed as the major factor, desensitizing the microbial community to the snow melt event. Nitrogen emerged as a limiting factor in surface ice habitats, especially to Eukaryotic algae. [ABSTRACT FROM AUTHOR]

Published
2015
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14. Linking environmental prokaryotic viruses and their host through CRISPRs.

Author

Sanguino, Laura, Franqueville, Laure, Vogel, Timothy M., and Larose, Catherine

Subjects
*PROKARYOTES, *HOSTS (Biology), *CRISPRS, *PREDATION, *BACTERIAL genomes, *GENETIC transduction, *BIOINFORMATICS
Abstract

The ecological pressure that viruses place on microbial communities is not only based on predation, but also on gene transfer. In order to determine the potential impact of viruses and transduction, we need a better understanding of the dynamics of interactions between viruses and their hosts in the environment. Data on environmental viruses are scarce, and methods for tracking their interactions with prokaryotes are needed. Clustered regularly interspaced short palindromic repeats (CRISPRs), which contain viral sequences in bacterial genomes, might help document the history of virus-host interactions in the environment. In this study, a bioinformatics network linking viruses and their hosts using CRISPR sequences obtained from metagenomic data was developed and applied to metagenomes from Arctic glacial ice and soil. The application of our network approach showed that putative interactions were more commonly detected in the ice samples than the soil which would be consistent with the ice viral-bacterial interactions being more dynamic than those in soil. Further analysis of the viral sequences in the CRISPRs indicated that Ralstonia phages might be agents of transduction in the Arctic glacial ice. [ABSTRACT FROM AUTHOR]

Published
2015
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15. Draft genome sequence of Dyadobacter tibetensis type strain (Y620-1) isolated from glacial ice.

Author

Liu, Yongqin, Hu, Anyi, Shen, Liang, Yao, Tandong, Jiao, Nianzhi, Wang, Ninglian, and Xu, Baiqing

Subjects
*GENOMES, *SNOW, *GLACIERS, *CRYOSPHERE
Abstract

Dyadobacter tibetensis Y620-1 is the type strain of the species Dyadobacter tibetensis, isolated from ice at a depth of 59 m from a high altitude glacier in China (5670 m above sea level). It is psychrotolerant with growth temperature ranges of 4 to 35°C. Here we describe the features of this organism, together with the draft genome sequence and annotation. The 5,313,963 bp long genome contains 4,828 protein-coding genes and 39 RNA genes. To the best of our knowledge, this is the first Dyadobacter strain that was isolated from glacial ice. This study provides genetic information of this organism to identify the genes linked to its specific mechanisms for adaption to extreme glacial environment. [ABSTRACT FROM AUTHOR]

Published
2014
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16. Greenland and Svalbard glaciers host unknown basidiomycetes: the yeast

Author

Laura, Perini, Kristina, Andrejašič, Cene, Gostinčar, Nina, Gunde-Cimerman, and Polona, Zalar

Subjects
glacial ice, New Taxa, filamentous, Basidiomycota, Greenland Ice Sheet, Greenland, Sequence Analysis, DNA, yeast, Microbotryomycetes, DNA, Ribosomal, Svalbard, Taxonomic Description, Yeasts, psychrophiles, Ice Cover, DNA, Fungal, Mycological Typing Techniques, Phylogeny, Eukaryotic Micro-Organisms
Abstract

Sampling campaigns in Greenland and Svalbard were executed to explore fungal diversity in cold habitats. Three very abundant groups of strains were discovered, consisting either of recently described or of yet-undescribed psychrophilic and oligotrophic yeasts and dimorphic fungi, accounting for around 50 % of the total cultivable diversity of basidiomycetes in our studies. The occurrence of these taxa has also been demonstrated by culture-independent methods. Based on phylogenetic analyses of ribosomal gene cluster sequences (D1/D2 domains of 28S (LSU), 18S (SSU), ITS with 5.8S rDNA) and sequences of protein-coding genes for elongation factor one alpha (TEF), cytochrome b (CYTB) and two subunits of the RNA polymerase II (RPB1 and RPB2) obtained from pure cultures, the isolated taxa presented in this study belong to Basidiomycota, subphylum Pucciniomycotina, class Microbotryomycetes, family Camptobasidiaceae. The dataset of the sequences supported the recognition of three species: Camptobasidium gelus, Camptobasidium arcticum sp. nov. (ex-type strain EXF-12713) and Psychromyces glacialis gen. and sp. nov. (ex-type strain EXF-13111). Camptobasidium gelus was found in the Svalbard and Greenland samples, while representatives of the here proposed new species, C. arcticum, were found only in the Greenland Ice Sheet. Psychromyces gen. nov. was erected for the dimorphic/filamentous isolates found in Svalbard and Greenland glacial environments. The taxon, for which the invalid name ‘Rhodotorula svalbardensis’ has been used, belongs to this genus. Based on ribosomal genes, Camptobasidium arcticum and Psychromyces glacialis are related, phylogenetically most closely related to the genera Glaciozyma and Cryolevonia. Seven genes phylogeny restricted to taxa with available sequences, supported the placement of Psychromyces to Camptobasidiaceae.

Published
2021

18. Searching for eV-scale sterile neutrinos with eight years of atmospheric neutrinos at the IceCube Neutrino Telescope

Author

Aartsen, M. G., Abbasi, R., Anderson, T., Gallagher, J., Ganster, E., Garrappa, S., Gerhardt, L., Glauch, T., Glüsenkamp, T., Goldschmidt, A., Gonzalez, J. G., Grant, D., Grégoire, T., Ansseau, I., Griffith, Z., Griswold, S., Günder, M., Gündüz, M., Haack, C., Hallgren, A., Halliday, R., Halve, L., Halzen, F., Hanson, K., Anton, G., Hardin, J., Haungs, A., Hauser, S., Hebecker, D., Heereman, D., Heix, P., Helbing, K., Hellauer, R., Henningsen, F., Hickford, S., Argüelles, C., Hignight, J., Hill, G. C., Hoffman, K. D., Hoffmann, R., Hoinka, T., Hokanson-Fasig, B., Hoshina, K., Huang, F., Huber, M., Huber, Thomas, Auffenberg, J., Hultqvist, K., Hünnefeld, M., Hussain, R., In, S., Iovine, N., Ishihara, A., Jansson, M., Japaridze, G. S., Jeong, M., Jones, B. J. P., Axani, S., Jonske, F., Joppe, R., Kang, D., Kang, W., Kappes, A., Kappesser, D., Karg, T., Karl, M., Karle, A., Katz, U., Bagherpour, H., Kauer, M., Kellermann, M., Kelley, J. L., Kheirandish, A., Kim, J., Kintscher, Thomas, Kiryluk, J., Kittler, T., Klein, S. R., Koirala, R., Bai, X., Kolanoski, H., Köpke, L., Kopper, C., Kopper, S., Koskinen, D. J., Koundal, P., Kowalski, M., Krings, K., Krückl, G., Kulacz, N., Balagopal, A., V., Kurahashi, N., Kyriacou, A., Lanfranchi, J. L., Larson, M. J., Lauber, F., Lazar, J. P., Leonard, K., Leszczyńska, A., Li, Y., Liu, Q. R., Barbano, A., Lohfink, E., Lozano Mariscal, C. J., Lu, L., Lucarelli, F., Ludwig, A., Lünemann, J., Luszczak, W., Lyu, Y., Ma, W. Y., Madsen, J., Ackermann, M., Barwick, S. W., Maggi, G., Mahn, K. B. M., Makino, Y., Mallik, P., Mancina, S., Mariş, I. C., Maruyama, R., Mase, K., Maunu, R., McNally, F., Bastian, B., Meagher, K., Medici, M., Medina, A., Meier, M., Meighen-Berger, S., Merz, J., Meures, T., Micallef, J., Mockler, D., Momenté, G., Basu, V., Montaruli, T., Moore, R. W., Morse, R., Moulai, M., Muth, P., Nagai, R., Naumann, U., Neer, G., Nguyen, L. V., Niederhausen, H., Baum, V., Nisa, M. U., Nowicki, S. C., Nygren, D. R., Obertacke Pollmann, A., Oehler, M., Olivas, A., O'Murchadha, A., O'Sullivan, E., Palczewski, T., Pandya, H., Baur, S., Pankova, D. V., Park, N., Parker, G. K., Paudel, E. N., Peiffer, P., Pérez de los Heros, C., Philippen, S., Pieloth, D., Pieper, S., Pinat, E., Bay, R., Pizzuto, A., Plum, M., Popovych, Y., Porcelli, A., Prado Rodriguez, M., Price, P. B., Przybylski, G. T., Raab, C., Raissi, A., Rameez, M., Beatty, J. J., Rauch, L., Rawlins, K., Rea, I. C., Rehman, A., Reimann, R., Relethford, B., Renschler, M., Renzi, G., Resconi, E., Rhode, W., Becker, K.-H., Richman, M., Riedel, B., Robertson, S., Rongen, M., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk Cantu, D., Safa, I., Sanchez Herrera, S. E., Becker Tjus, J., Sandrock, A., Sandroos, J., Santander, M., Sarkar, S., Satalecka, K., Scharf, M., Schaufel, M., Schieler, H., Schlunder, P., BenZvi, S., Schmidt, T., Schneider, A., Schneider, J., Schröder, F. G., Schumacher, L., Sclafani, S., Seckel, D., Seunarine, S., Shefali, S., Silva, M., Adams, J., Berley, D., Smithers, B., Snihur, R., Soedingrekso, J., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stachurska, J., Stamatikos, M., Stanev, T., Bernardini, E., Stein, Robert, Stettner, J., Steuer, A., Stezelberger, T., Stokstad, R. G., Stössl, A., Strotjohann, Nora Linn, Stürwald, T., Stuttard, T., Sullivan, G. W., Besson, D. Z., Taboada, I., Tenholt, F., Ter-Antonyan, S., Terliuk, Andrii, Tilav, S., Tollefson, K., Tomankova, L., Tönnis, C., Toscano, S., Tosi, D., Binder, G., Trettin, A., Tselengidou, M., Tung, C. F., Turcati, A., Turcotte, R., Turley, C. F., Ty, B., Unger, E., Unland Elorrieta, M. A., Usner, Marcel, Bindig, D., Vandenbroucke, J., Van Driessche, W., van Eijk, D., van Eijndhoven, N., Vannerom, D., Santen, Jakob van, Verpoest, S., Vraeghe, M., Walck, C., Wallace, A., Blaufuss, E., Wallraff, M., Watson, T. B., Weaver, C., Weindl, A., Weiss, M. J., Weldert, J., Wendt, C., Werthebach, J., Whelan, B. J., Whitehorn, N., Blot, S., Wiebe, K., Wiebusch, C. H., Williams, D. R., Wills, L., Wolf, M., Wood, T. R., Woschnagg, K., Wrede, G., Wulff, J., Xu, X. W., Bohm, C., Xu, Y., Yanez, J. P., Yodh, G., Yoshida, S., Yuan, T., Zhang, Z., Zöcklein, M., IceCube Collaboration, Böser, S., Botner, O., Aguilar, J. A., Böttcher, J., Bourbeau, E., Bourbeau, J., Bradascio, F., Braun, J., Bron, S., Brostean-Kaiser, J., Burgman, A., Buscher, J., Busse, R. S., Ahlers, M., Carver, T., Chen, C., Cheung, E., Chirkin, D., Choi, S., Clark, B. A., Clark, K., Classen, L., Coleman, A., Collin, G. H., Ahrens, M., Conrad, J. M., Coppin, P., Correa, P., Cowen, D. F., Cross, R., Dave, P., De Clercq, C., DeLaunay, J. J., Dembinski, H., Deoskar, K., Alispach, C., De Ridder, S., Desai, A., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., DeYoung, T., Dharani, S., Diaz, A., Díaz-Vélez, J. C., Amin, N. M., Dujmovic, H., Dunkman, M., DuVernois, M. A., Dvorak, E., Ehrhardt, T., Eller, P., Engel, R., Evenson, P. A., Fahey, S., Fazely, A. R., Andeen, K., Fedynitch, A., Felde, J., Fienberg, A. T., Filimonov, K., Finley, C., Fox, D., Franckowiak, Anna, Friedman, E., Fritz, A., Gaisser, T. K., Physics, Faculty of Sciences and Bioengineering Sciences, Vriendenkring VUB, and Elementary Particle Physics

Subjects
Sterile neutrino, Physics::Instrumentation and Detectors, PROTON, sterile [neutrino], 01 natural sciences, High Energy Physics - Experiment, CROSS-SECTIONS, IceCube, Subatomär fysik, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Astronomi, astrofysik och kosmologi, neutrino: atmosphere, Subatomic Physics, Astronomy, Astrophysics and Cosmology, detector [neutrino], Physics, oscillation [neutrino], Astrophysics::Instrumentation and Methods for Astrophysics, hep-ph, OPTICAL-PROPERTIES, neutrino: sterile, atmosphere [neutrino], mass difference [neutrino], ddc, High Energy Physics - Phenomenology, neutrino: detector, Physique des particules élémentaires, SOUTH-POLE ICE, Neutrino, data analysis method, Astrophysics::High Energy Astrophysical Phenomena, Neutrino telescope, neutrino: mass difference, FOS: Physical sciences, Context (language use), statistical analysis, 0103 physical sciences, OSCILLATIONS, conservation law, ddc:530, 010306 general physics, hep-ex, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Astronomy, neutrino: mixing angle, CONVERSION, Physics and Astronomy, LSND, RESOLUTION, High Energy Physics::Experiment, neutrino: oscillation, GLACIAL ICE, mixing angle [neutrino], experimental results
Abstract

Physical review / D D102(5), 052009 (1-32) (2020). doi:10.1103/PhysRevD.102.052009, We report in detail on searches for eV-scale sterile neutrinos, in the context of a 3+1 model, using eight years of data from the IceCube neutrino telescope. By analyzing the reconstructed energies and zenith angles of 305,735 atmospheric $\nu_\mu$ and $\bar{\nu}_\mu$ events we construct confidence intervals in two analysis spaces: $\sin^2 (2\theta_{24})$ vs. $\Delta m^2_{41}$ under the conservative assumption $\theta_{34}=0$; and $\sin^2(2\theta_{24})$ vs. $\sin^2 (2\theta_{34})$ given sufficiently large $\Delta m^2_{41}$ that fast oscillation features are unresolvable. Detailed discussions of the event selection, systematic uncertainties, and fitting procedures are presented. No strong evidence for sterile neutrinos is found, and the best-fit likelihood is consistent with the no sterile neutrino hypothesis with a p-value of 8% in the first analysis space and 19% in the second., Published by Inst.302363, Melville, NY

Published
2020

19. On the shape factor in iceberg deterioration by forced convection.

Author

Shipilova, Olga, Olsson, Andreas, and Thomson, Mark

Subjects
*BOUNDARY layer equations, *FORCED convection, *HEAT convection, *AXIAL flow, *ICEBERGS, *THREE-dimensional flow, *BOUNDARY layer (Aerodynamics)
Abstract

The present paper concerns the conventional use, in offshore ice engineering, of the convective heat transfer equation presented by White, et al. (1980) for iceberg keel degradation due to forced convection. The equation describing loss of iceberg keel mass involves a shape factor which depends on both the actual shape of the keel and on the governing convective heat transfer law applicable across the boundary layer over the keel. Two shape factor values from White et al. (1980) depend on a binary overall shape classification: tabular and non-tabular icebergs. Since the relative mass loss varies linearly with the shape factor, any uncertainty in it propagates directly into the mass loss model. The formulation proposed in White et al. (1980) is justified for very wide icebergs in a flow which can be presented as two-dimensional. However, it is not clear whether all arbitrary icebergs in arbitrary flow may be represented by the same shape factor values and how the shape factor over an ensemble of tabular or non-tabular icebergs would vary. The present work provides further insight into the quantification of the shape factor. For this, the model provided in White et al. (1980) is applied to several analytical geometrical shapes in either two-dimensional flow or three-dimensional axisymmetric flow. The iceberg keel is presented either by half of a cylinder with elliptic cross-section or by half of a spheroid, i.e., a body of revolution. The shape factor values for the analytical shapes have been found to be around 12%–20% lower than the shape factors given in White et al. (1980). The values reported here for the elliptic deep half-cylinder can be used as conservative limit for engineering estimations of the iceberg deterioration rate due to forced convection. • Standard shape factors might yield overestimation of iceberg deterioration rate. • The shape factor based on deep cylinder is recommended for engineering applications. • Shape variation within iceberg type is described via longitudinal eccentricity. • Type of iceberg shape affects shape factor more than way of flow description. [ABSTRACT FROM AUTHOR]

Published
2022
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20. Microbial Analyses of Ancient Ice Core Sections from Greenland and Antarctica.

Author

Knowlton, Caitlin, Veerapaneni, Ram, D'Elia, Tom, and Rogers, Scott O.

Subjects
*ICE cores, *ATMOSPHERE, *SCANNING electron microscopy
Abstract

Ice deposited in Greenland and Antarctica entraps viable and nonviable microbes, as well as biomolecules, that become temporal atmospheric records. Five sections (estimated to be 500, 10,500, 57,000, 105,000 and 157,000 years before present, ybp) from the GISP2D (Greenland) ice core, three sections (500, 30,000 and 70,000 ybp) from the Byrd ice core, and four sections from the Vostok 5G (Antarctica) ice core (10,500, 57,000, 105,000 and 105,000 ybp) were studied by scanning electron microscopy, cultivation and rRNA gene sequencing. Bacterial and fungal isolates were recovered from 10 of the 12 sections. The highest numbers of isolates were found in ice core sections that were deposited during times of low atmospheric CO2, low global temperatures and low levels of atmospheric dust. Two of the sections (GISP2D at 10,500 and 157,000 ybp) also were examined using metagenomic/metatranscriptomic methods. These results indicated that sequences from microbes common to arid and saline soils were deposited in the ice during a time of low temperature, low atmospheric CO2 and high dust levels. Members of Firmicutes and Cyanobacteria were the most prevalent bacteria, while Rhodotorula species were the most common eukaryotic representatives. Isolates of Bacillus, Rhodotorula, Alternaria and members of the Davidiellaceae were isolated from both Greenland and Antarctica sections of the same age, although the sequences differed between the two polar regions. [ABSTRACT FROM AUTHOR]

Published
2013
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21. Antarctic circumpolar current's role in the Antarctic ice system: An overview

Author

Martinson, Douglas G.

Subjects
*ANTARCTIC Circumpolar Current, *ICE sheets, *OCEAN surface topography, *SEA ice, *HEAT flux, *ANTARCTIC ice, *OCEAN currents
Abstract

Abstract: The Antarctic Circumpolar Current (ACC) provides fundamental control on the Antarctic ice system. The tilt of the isopycnals of the ACC, in response to strong westerlies, serves to thermally isolate the Antarctic continent from directly receiving the overwhelming subtropical ocean surface heat. This same tilt provides the northern boundary of the polar seas; as such it “contains” the statically stable cold fresh surface polar waters required for sea ice formation. In this manner it effectively sets the northern limit for seasonal sea ice formation. The isopycnal tilt also allows warm deep water to upwell to the surface near the continental margin in western Antarctica where the ACC skirts the continental shelf, leading to excessive ocean heat flux to the atmosphere in winter, and providing heat to melt the underside of the glacial ice. [Copyright &y& Elsevier]

Published
2012
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22. Ultrawideband Gated Step Frequency Ground-Penetrating Radar.

Author

Oyan, M. J., Hamran, S., Hanssen, L., Berger, T., and Plettemeier, D.

Subjects
*LAND cover, *LAPLACIAN operator, *SYNTHETIC aperture radar, *ULTRA-wideband radar, *SIGNAL processing, *ICE sheets, *PERMAFROST
Abstract

We describe a prototype ultrawideband radar. We show how the system was designed and how the hardware was developed for the radar prototype. Waveform generation, radar parameters, and signal processing for the stepped frequency waveform are discussed. The radar operates from 500 MHz to 3 GHz with a nominal resolution of 6 cm in air. The advantage of the stepped frequency approach over an impulse radar is better matching between the transmitted waveform and the receiver. We use range gating to improve the system dynamic range. The advantages are illustrated with laboratory measurements and field measurements from glacial ice and permafrost in Svalbard, showing penetration depths of 11 m. Antennas which do not require contact with the ground were developed and used in the experiments. [ABSTRACT FROM AUTHOR]

Published
2012
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23. Comparison of impact forces measured by different instrumentation systems on the CCGS Terry Fox during the Bergy Bit Trials

Author

Johnston, M., Ritch, R., and Gagnon, R.

Subjects
*MECHANICS (Physics), *INERTIAL navigation systems, *SHIPS, *SHIP hull fouling
Abstract

Abstract: A comparison of the forces that were measured by different instrumentation systems during a number of ship collisions with bergy bits is presented. Three types of instruments were used to measure ship impact forces: an inertial measurement system called MOTAN, a 5.4 m2 strain gauged area and a 3.5 m2 external Impact Panel. Forces on the Impact Panel were consistently lower than forces on the strain gauged area, for different impacts. The maximum force on the Impact Panel was 1.2 MN, and the highest force on the strain gauged area was 5.1 MN. Forces from MOTAN are calculated using two different approaches; one requires information about where the impact occurred, and the other does not. The agreement in forces from MOTAN and the strain gauged area or Impact Panel depended upon how completely the hull instrumentation captured the loaded area. When the strain gauged area provided good coverage of the loaded area (7 impacts), forces from MOTAN were from 17% lower to 33% higher than forces on the strain gauged area, if the impact location was used to calculate the forces. When the impact location was not used in the calculation, forces from MOTAN were up to 120% higher than forces on the strain gauged area. The four most significant impacts to the Impact Panel, all of which extended beyond the Panel''s sensing area, indicated that forces from MOTAN were from 11% lower to 233% higher than forces on the Impact Panel. [Copyright &y& Elsevier]

Published
2008
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24. Molecular identification of Bacteria and Eukarya inhabiting an Antarctic cryoconite hole.

Author

Christner, Brent C., Kvitko, Brian H., and Reeve, John N.

Subjects
*CRYOCONITE, *DNA, *GENE amplification, *NUCLEOTIDE sequence, *CYANOBACTERIA, *CYTOPHAGALES
Abstract

Inhabitants of a cryoconite hole formed in the Canada Glacier in the McMurdo Dry Valley region of Antarctica have been isolated and identified by small subunit (16S/18S) rDNA amplification, cloning, and sequencing. The sequences obtained revealed the presence of members of eight bacterial lineages (Acidobacterium, Actinobacteria, Cyanobacteria, Cytophagales, Gemmimonas, Planctomycetes, Proteobacteria, and Verrucomicrobia) and metazoan (nematode, tardigrade, and rotifer), truffle (Choiromyces), ciliate (Spathidium), and green algal (Pleurastrium) Eukarya. Bacterial recovery was ~20-fold higher at 4 °C and 15 °C than at 22 °C, and obligately psychrophilic bacteria were identified and isolated. Several of the rDNA molecules amplified from isolates and directly from cryoconite DNA preparations had sequences similar to rDNA molecules of species present in adjacent lake ice and microbial mat environments. This cryoconite hole community was therefore most likely seeded by particulates from these local environments. Cryoconite holes may serve as biological refuges that, on glacial melting, can repopulate the local environments. [ABSTRACT FROM AUTHOR]

Published
2003
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25. Microbial community development on the surface of Hans and Werenskiold Glaciers (Svalbard, Arctic): a comparison

Author

Tamara Aleksandrzak-Piekarczyk, Katarzyna Szatraj, Jakub Grzesiak, Dorota Górniak, Aleksander Świątecki, and Marek K. Zdanowski

Subjects
Microbiology, Cryoconite, Microbial community, Snow line, Photoautotroph, Glacial ice, Ice Cover, Microbial abundance, geography, Original Paper, geography.geographical_feature_category, Ecology, Arctic Regions, Microbiota, Cryoconite holes, Tidewater glacier cycle, Sediment, Glacier, General Medicine, Glacier morphology, Tundra, Arctic, Environmental science, Molecular Medicine, Physical geography, Tidewater glacier
Abstract

Surface ice and cryoconite holes of two types of polythermal Svalbard Glaciers (Hans Glacier—grounded tidewater glacier and Werenskiold Glacier—land-based valley glacier) were investigated in terms of chemical composition, microbial abundance and diversity. Gathered data served to describe supraglacial habitats and to compare microbe–environment interactions on those different type glaciers. Hans Glacier samples displayed elevated nutrient levels (DOC, nitrogen and seston) compared to Werenskiold Glacier. Adjacent tundra formations, bird nesting sites and marine aerosol were candidates for allochtonic enrichment sources. Microbial numbers were comparable on both glaciers, with surface ice containing cells in the range of 104 mL−1 and cryoconite sediment 108 g−1 dry weight. Denaturating gradient gel electrophoresis band-based clustering revealed differences between glaciers in terms of dominant bacterial taxa structure. Microbial community on Werenskiold Glacier benefited from the snow-released substances. On Hans Glacier, this effect was not as pronounced, affecting mainly the photoautotrophs. Over-fertilization of Hans Glacier surface was proposed as the major factor, desensitizing the microbial community to the snow melt event. Nitrogen emerged as a limiting factor in surface ice habitats, especially to Eukaryotic algae. Electronic supplementary material The online version of this article (doi:10.1007/s00792-015-0764-z) contains supplementary material, which is available to authorized users.

Published
2015

26. Glacial ice impacts: Part I: Wave-driven motion and small glacial ice feature impacts.

Author

Lu, Wenjun, Amdahl, Jørgen, Lubbad, Raed, Yu, Zhaolong, and Løset, Sveinung

Subjects
*OFFSHORE structures, *RELATIVE motion, *OCEAN waves, *MOTION analysis, *MOTION, *WEIBULL distribution, *AXIOMATIC design
Abstract

Glacial ice features in the northern and central Barents Sea may threaten ships and offshore structures. Particularly, small glacial ice features, which are difficult to detect and manage by concurrent technologies, are of concern. Additionally, small glacial ice features are more susceptible to wave-driven oscillatory motions, which increases their pre-impact kinetic energy and may damage ships and offshore structures. This paper is part of three related papers. An initial paper (Monteban et al., 2020) studied glacial ice features' drift, size distribution and encounter frequencies with an offshore structure in the Barents Sea. The following two papers (Paper I and Paper II) further performed glacial ice impact studies, including impact motion analysis (Paper I) and structural damage assessment (Paper II). This paper (Paper I) studies the wave-driven motion of small glacial ice features and their subsequent impact with a given offshore structure. The aim here is to develop a numerical model that is capable of efficiently calculating the relative motion between the ice feature and structure and to sample a sufficient amount of impact events from which statistical information can be obtained. The statistical information entails the distributions of the impact location and associated impact velocities. Given the distributions of the impact velocities at different locations, we can quantify the kinetic energy for related impact scenarios for a further structural damage assessment in Paper II (Yu et al., 2020). In Paper I, a numerical model that separately calculates the wave-driven oscillatory motion and the mean drift motion of small glacial ice features is proposed, implemented and validated. Practical and fit-for-purpose hydrodynamic simplifications are made to simulate and sample sufficient impact events. The numerical model has been favourably validated against existing numerical results and experimental data. A case study is presented where a 10 m wide glacial ice feature is drifting under the influence of surface waves towards an offshore structure. The case study shows that if an impact happens, the overall impact location and impact velocity can be best fitted by the Normal and Weibull distributions, respectively. Additionally, the impact velocity increases with impact height. Moreover, the impact velocity increases and the impact range is more dispersed in a higher sea state. It is also important to notice that the approaches and methods proposed in this paper adhere to and reflect the general requirements stated in ISO19906 (2019) and NORSOK N-003 (2017) for estimating the design kinetic energy for glacial ice impacts. • An efficient numerical model was developed to calculate the wave-driven motions of small glacial ice features irregular wave conditions. • The numerical model is extensively validated against existing numerical and (lab- and field-) experimental data. • A method to efficiently sample ice – structure impact events was extended from an existing ship-platform collision method. • The impact probability in the height direction is found to be a Normal distribution and the impact velocity is found to be a Weibull distribution. • The general trends of the impact velocity and location's dependence on different wave conditions are demonstrated. [ABSTRACT FROM AUTHOR]

Published
2021
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27. The IceCube Neutrino Observatory: instrumentation and online systems

Author

Aartsen, M. G., Ackermann, M., Anton, G., Gaisser, T. K., Gallagher, J., Gerhardt, L., Ghorbani, K., Giang, W., Gladstone, L., Glauch, T., Glowacki, D., Glüsenkamp, T., Goldschmidt, A., Archinger, M., Gonzalez, J. G., Grant, D., Griffith, Z., Gustafsson, L., Haack, C., Hallgren, A., Halzen, F., Hansen, E., Hansmann, T., Hanson, K., Argüelles, C., Haugen, J., Hebecker, D., Heereman, D., Helbing, K., Hellauer, R., Heller, R., Hickford, S., Hignight, J., Hill, G. C., Hoffman, K. D., Auer, R., Hoffmann, R., Hoshina, K., Huang, F., Huber, M., Hulth, P. O., Hultqvist, K., In, S., Inaba, M., Ishihara, A., Jacobi, E., Auffenberg, J., Jacobsen, J., Japaridze, G. S., Jeong, M., Jero, K., Jones, A., Jones, B. J. P., Joseph, J., Kang, W., Kappes, A., Karg, T., Axani, S., Karle, A., Katz, U., Kauer, M., Keivani, A., Kelley, J. L., Kemp, J., Kheirandish, A., Kim, J., Kim, M., Kintscher, T., Baccus, J., Kiryluk, J., Kitamura, N., Kittler, T., Klein, S. R., Kleinfelder, S., Kleist, M., Kohnen, G., Koirala, R., Kolanoski, H., Konietz, R., Bai, X., Köpke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krasberg, M., Krings, K., Kroll, M., Krückl, G., Krüger, C., Barnet, S., Kunnen, J., Kunwar, S., Kurahashi, N., Kuwabara, T., Labare, M., Laihem, K., Landsman, H., Lanfranchi, J. L., Larson, M. J., Lauber, F., Barwick, S. W., Laundrie, A., Lennarz, D., Leich, H., Lesiak-Bzdak, M., Leuermann, M., Lu, L., Ludwig, J., Lünemann, J., Mackenzie, C., Madsen, J., Adams, J., Baum, V., Maggi, G., Mahn, K. B. M., Mancina, S., Mandelartz, M., Maruyama, R., Mase, K., Matis, H., Maunu, R., McNally, F., McParland, C. P., Bay, R., Meade, P., Meagher, K., Medici, M., Meier, M., Meli, A., Menne, T., Merino, G., Meures, T., Miarecki, S., Minor, R. H., Beattie, K., Montaruli, T., Moulai, M., Murray, T., Nahnhauer, R., Naumann, U., Neer, G., Newcomb, M., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Beatty, J. J., Pollmann, A. Obertacke, Olivas, A., O'Murchadha, A., Palczewski, T., Pandya, H., Pankova, D. V., Patton, S., Peiffer, P., Penek, Ö., Pepper, J. A., Tjus, J. Becker, Heros, C. Pérez de los, Pettersen, C., Pieloth, D., Pinat, E., Price, P. B., Przybylski, G. T., Quinnan, M., Raab, C., Rädel, L., Rameez, M., Becker, K.-H., Rawlins, K., Reimann, R., Relethford, B., Relich, M., Resconi, E., Rhode, W., Richman, M., Riedel, B., Robertson, S., Rongen, M., Bendfelt, T., Roucelle, C., Rott, C., Ruhe, T., Ryckbosch, D., Rysewyk, D., Sabbatini, L., Herrera, S. E. Sanchez, Sandrock, A., Sandroos, J., Sandstrom, P., BenZvi, S., Sarkar, S., Satalecka, K., Schlunder, P., Schmidt, T., Schoenen, S., Schöneberg, S., Schukraft, A., Schumacher, L., Seckel, D., Seunarine, S., Berley, D., Solarz, M., Soldin, D., Song, M., Spiczak, G. M., Spiering, C., Stanev, T., Stasik, A., Stettner, J., Steuer, A., Stezelberger, T., Bernardini, E., Stokstad, R. G., Stößl, A., Ström, R., Strotjohann, N. L., Sulanke, K.-H., Sullivan, G. W., Sutherland, M., Taavola, H., Taboada, I., Tatar, J., Aguilar, J. A., Bernhard, A., Tenholt, F., Ter-Antonyan, S., Terliuk, A., Tešić, G., Thollander, L., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tosi, D., Besson, D. Z., Tselengidou, M., Turcati, A., Unger, E., Usner, M., Vandenbroucke, J., Eijndhoven, N. van, Vanheule, S., Rossem, M. van, Santen, J. van, Vehring, M., Binder, G., Voge, M., Vogel, E., Vraeghe, M., Wahl, D., Walck, C., Wallace, A., Wallraff, M., Wandkowsky, N., Weaver, Ch., Weiss, M. J., Bindig, D., Wendt, C., Westerhoff, S., Wharton, D., Whelan, B. J., Wickmann, S., Wiebe, K., Wiebusch, C. H., Wille, L., Williams, D. R., Wills, L., Bissok, M., Wisniewski, P., Wolf, M., Wood, T. R., Woolsey, E., Woschnagg, K., Xu, D. L., Xu, X. W., Xu, Y., Yanez, J. P., Yodh, G., Blaufuss, E., Yoshida, S., Zoll, M., IceCube Collaboration, Blot, S., Boersma, D., Bohm, C., Börner, M., Ahlers, M., Bos, F., Bose, D., Böser, S., Botner, O., Bouchta, A., Braun, J., Brayeur, L., Bretz, H.-P., Bron, S., Burgman, A., Ahrens, M., Burreson, C., Carver, T., Casier, M., Cheung, E., Chirkin, D., Christov, A., Clark, K., Classen, L., Coenders, S., Collin, G. H., Altmann, D., Conrad, J. M., Cowen, D. F., Cross, R., Day, C., Day, M., de André, J. P. A. M., Clercq, C. De, Rosendo, E. del Pino, Dembinski, H., Ridder, S. De, Andeen, K., Descamps, F., Desiati, P., de Vries, K. D., de Wasseige, G., de With, M., DeYoung, T., Díaz-Vélez, J. C., di Lorenzo, V., Dujmovic, H., Dumm, J. P., Anderson, T., Dunkman, M., Eberhardt, B., Edwards, W. R., Ehrhardt, T., Eichmann, B., Eller, P., Euler, S., Evenson, P. A., Fahey, S., Fazely, A. R., Ansseau, I., Feintzeig, J., Felde, J., Filimonov, K., Finley, C., Flis, S., Fösig, C.-C., Franckowiak, A., Frère, M., Friedman, E., and Fuchs, T.

Subjects
NEEM ICE CORE, AMANDA, Technology and Engineering, Physics - Instrumentation and Detectors, TELESCOPE, Computer science, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, Real-time computing, FOS: Physical sciences, STRATIGRAPHY, Cosmic ray, DATA-ACQUISITION SYSTEM, Online farms and online filtering, 01 natural sciences, IceCube Neutrino Observatory, DESIGN, SOUTH-POLE, 0103 physical sciences, RECONSTRUCTION, Neutrino detectors, Instrumentation (computer programming), ddc:610, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Instrumentation, Mathematical Physics, Large detector systems for particle and astroparticle physics, 010308 nuclear & particles physics, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Instrumentation and Detectors (physics.ins-det), PERFORMANCE, Trigger concepts and systems (hardware and software), Physics and Astronomy, Neutrino detector, High Energy Physics::Experiment, Neutrino, Astrophysics - Instrumentation and Methods for Astrophysics, GLACIAL ICE
Abstract

The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy neutrino detector built into the ice at the South Pole. Construction of IceCube, the largest neutrino detector built to date, was completed in 2011 and enabled the discovery of high-energy astrophysical neutrinos. We describe here the design, production, and calibration of the IceCube digital optical module (DOM), the cable systems, computing hardware, and our methodology for drilling and deployment. We also describe the online triggering and data filtering systems that select candidate neutrino and cosmic ray events for analysis. Due to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are operating and collecting data. IceCube routinely achieves a detector uptime of 99% by emphasizing software stability and monitoring. Detector operations have been stable since construction was completed, and the detector is expected to operate at least until the end of the next decade., 83 pages, 50 figures; updated with minor changes from journal review and proofing

Published
2017

28. A global multiproxy database for temperature reconstructions of the Common Era

Author

Dmitry Divine, Dmitriy V. Ovchinnikov, Hugues Goosse, Marit-Solveig Seidenkrantz, Anne Hormes, Narayan Prasad Gaire, Joelle Gergis, Katrine Husum, David J. Nash, Konrad Gajewski, Jens Zinke, Vladimir Mikhalenko, Darrell S. Kaufman, Eugene R. Wahl, Martin Grosjean, Nancy A. N. Bertler, Pierre Francus, Anastasia Gornostaeva, Diana Vladimirova, Kaustubh Thirumalai, Lucien von Gunten, Kevin J. Anchukaitis, Michael Sigl, Ryu Uemura, Michael N. Evans, Hideaki Motoyama, Scott St. George, Marie-Alexandrine Sicre, Chris S. M. Turney, Johannes P. Werner, Robert Mulvaney, Jianghao Wang, Brian M. Chase, Mark A. J. Curran, Julien Emile-Geay, Takeshi Nakatsuka, David J. Sauchyn, Nerilie J. Abram, Bronwyn C. Dixon, Raphael Neukom, Cody C. Routson, Trevor J. Porter, Selvaraj Kandasamy, Mirko Severi, Massimo Frezzotti, Steven J. Phipps, Hans W. Linderholm, A. E. Viau, P. Graham Mortyn, Jessica E. Tierney, Eric J. Steig, Heidi A. Roop, K. Halimeda Kilbourne, Jason A. Addison, Jonathan J. Tyler, Mandy Freund, Daniel A. Dixon, Belen Martrat, Chenxi Xu, Krystyna M. Saunders, Min Te Chen, Xuemei Shao, Vasile Ersek, Philipp Munz, Hans Oerter, Masaki Sano, Zhixin Hao, Meloth Thamban, Alexey A. Ekaykin, Barbara Stenni, Kazuho Horiuchi, Ignacio A. Mundo, Zicheng Yu, Gregory T. Pederson, James W. C. White, Nalan Koc, Elisabeth Isaksson, Kathryn Allen, Rixt de Jong, Jeannine-Marie St. Jacques, Andrew Lorrey, Guillaume Leduc, Quansheng Ge, Kristine L. DeLong, Kenji Kawamura, Anais Orsi, Thomas Opel, Edward R. Cook, Kate E. Sinclair, Benjamin J. Henley, Nicholas P. McKay, Helen McGregor, Andrew D. Moy, Elizabeth R. Thomas, Jesper Björklund, Helena L. Filipsson, Udya Kuwar Thapa, Casey Saenger, Northern Arizona University [Flagstaff], Australian National University (ANU), United States Geological Survey [Reston] (USGS), University of Maryland [College Park], University of Maryland System, Spanish National Research Council [Madrid] (CSIC), School of Biological, Earth and Environmental Sciences [Sydney] (BEES), University of New South Wales [Sydney] (UNSW), Oeschger Centre for Climate Change Research (OCCR), University of Bern, Dipartimento di Scienze Geologiche [Trieste], Università degli studi di Trieste, University of Texas at Austin [Austin], Department of Earth and Space Sciences [Seattle], University of Washington [Seattle], Department of Earth Sciences [Oxford], University of Oxford [Oxford], Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Climate Change Institute (CCI), University of Maine, University of Northumbria at Newcastle [United Kingdom], Lund University [Lund], Centre Eau Terre Environnement - INRS (INRS-ETE), Institut National de la Recherche Scientifique [Québec] (INRS), Italian National agency for new technologies, Energy and sustainable economic development [Frascati] (ENEA), Nepal Academy of Science and Technology, Université Catholique de Louvain (UCL), Quaternary Geology, The University Centre in Svalbard (UNIS), Norwegian Polar Institute, Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], University of Maryland Center for Environmental Science, Horn Point Laboratory, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Universitat Autònoma de Barcelona [Barcelona] (UAB), National Institute of Polar Research [Tokyo] (NiPR), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), School of Environment and Technology, University of Brighton, Abteilung Klinische Sozialmedizin, Berufs- und Umweltdermatologie, Universität Heidelberg [Heidelberg], Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Université Panthéon-Sorbonne (UP1), Aarhus University [Aarhus], Department of Chemistry, University of Florence (UNIFI), Biogéochimie-Traceurs-Paléoclimat (BTP), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Paul Scherrer Institute (PSI), University of the Ryukyus [Okinawa], Australian Institute of Marine Science (AIMS), PAGES 2k, Università degli studi di Trieste = University of Trieste, University of Oxford, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Climate Change Institute [Orono] (CCI), Centre Eau Terre Environnement [Québec] (INRS - ETE), Université Catholique de Louvain = Catholic University of Louvain (UCL), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universitat Autònoma de Barcelona (UAB), Universität Heidelberg [Heidelberg] = Heidelberg University, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Glaces et Continents, Climats et Isotopes Stables (GLACCIOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), The University of Tokyo (UTokyo), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Firenze = University of Florence (UniFI), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Università degli Studi di Firenze = University of Florence [Firenze] (UNIFI), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Emile-Geay, J., Mckay, N. P., Kaufman, D. S., Von Gunten, L., Wang, Junrong, Anchukaitis, K. J., Abram, N. J., Addison, J. A., Curran, M. A. J., Evans, M. N., Henley, B. J., Hao, Z., Martrat, B., Mcgregor, H. V., Neukom, R., Pederson, G. T., Stenni, B., Thirumalai, K., Werner, J. P., Xu, C., Divine, D. V., Dixon, B. C., Gergis, J., Mundo, I. A., Nakatsuka, T., Phipps, S. J., Routson, C. C., Steig, E. J., Tierney, J. E., Tyler, J. J., Allen, K. J., Bertler, N. A. N., Bjorklund, J., Chase, B. M., Chen, M. -T., Cook, E., De Jong, R., Delong, K. L., Dixon, D. A., Ekaykin, A. A., Ersek, V., Filipsson, H. L., Francus, P., Freund, M. B., Frezzotti, M., Gaire, N. P., Gajewski, K., Ge, Q., Goosse, H., Gornostaeva, A., Grosjean, M., Horiuchi, K., Hormes, A., Husum, K., Isaksson, E., Kandasamy, S., Kawamura, K., Kilbourne, K. H., Koc, N., Leduc, G., Linderholm, H. W., Lorrey, A. M., Mikhalenko, V., Mortyn, P. G., Motoyama, H., Moy, A. D., Mulvaney, R., Munz, P. M., Nash, D. J., Oerter, H., Opel, T., Orsi, A. J., Ovchinnikov, D. V., Porter, T. J., Roop, H. A., Saenger, C., Sano, M., Sauchyn, D., Saunders, K. M., Seidenkrantz, M. -S., Severi, M., Shao, X., Sicre, M. -A., Sigl, M., Sinclair, K., St George, S., St Jacques, J. -M., Thamban, M., Thapa, U. K., Thomas, E. R., Turney, C., Uemura, R., Viau, A. E., Vladimirova, D. O., Wahl, E. R., White, J. W. C., Yu, Z., Zinke, J., École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, and UCL - SST/ELI/ELIC - Earth & Climate

Subjects
Data Descriptor, 010504 meteorology & atmospheric sciences, VDP::Mathematics and natural science: 400::Mathematics: 410::Statistics: 412, VDP::Matematikk og Naturvitenskap: 400::Matematikk: 410::Statistikk: 412, F800, computer.software_genre, Palaeoclimate, 01 natural sciences, Proxy (climate), CECI [CISM], calcification, data integration objective, Climate change, trace metal analysis, 910 Geography & travel, geography.geographical_feature_category, Database, G500, data acquisition system, temperature of environmental material, Computer Science Applications, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, Temperature reconstruction, Statistics, Probability and Uncertainty, Tree ring, Geology, wood, Information Systems, Statistics and Probability, glacial ice, radiance, 010506 paleontology, observation design, Library and Information Sciences, archaeal metabolite, Education, time series design, stable isotope analysis, Dendrochronology, 550 Earth sciences & geology, 0105 earth and related environmental sciences, geography, Global temperature, Glacier, 15. Life on land, Sea surface temperature, sediment, 13. Climate action, North Atlantic oscillation, Oceanic basin, computer
Abstract

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high- and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python., PAGES, a core project of Future Earth, is supported by the U.S. and Swiss National Science Foundations. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Some of this work was conducted as part of the North America 2k Working Group supported by the John Wesley Powell Center for Analysis and Synthesis, funded by the U.S. Geological Survey. B. Bauer, W. Gross, and E. Gille (NOAA National Centers for Environmental Information) are gratefully acknowledged for helping assemble the data citations and creating the NCEI versions of the PAGES 2k data records. We thank all the investigators whose commitment to data sharing enables the open science ethos embodied by this project.

Published
2017

29. Greenland and Svalbard glaciers host unknown basidiomycetes: the yeast Camptobasidium arcticum sp. nov. and the dimorphic Psychromyces glacialis gen. and sp. nov.

Author

Perini L, Andrejašič K, Gostinčar C, Gunde-Cimerman N, and Zalar P

Subjects
Basidiomycota isolation & purification, DNA, Fungal genetics, DNA, Ribosomal genetics, Greenland, Mycological Typing Techniques, Sequence Analysis, DNA, Svalbard, Yeasts classification, Basidiomycota classification, Ice Cover microbiology, Phylogeny
Abstract

Sampling campaigns in Greenland and Svalbard were executed to explore fungal diversity in cold habitats. Three very abundant groups of strains were discovered, consisting either of recently described or of yet-undescribed psychrophilic and oligotrophic yeasts and dimorphic fungi, accounting for around 50 % of the total cultivable diversity of basidiomycetes in our studies. The occurrence of these taxa has also been demonstrated by culture-independent methods. Based on phylogenetic analyses of ribosomal gene cluster sequences (D1/D2 domains of 28S (LSU), 18S (SSU), ITS with 5.8S rDNA) and sequences of protein-coding genes for elongation factor one alpha ( TEF ), cytochrome b ( CYTB ) and two subunits of the RNA polymerase II ( RPB1 and RPB2 ) obtained from pure cultures, the isolated taxa presented in this study belong to Basidiomycota, subphylum Pucciniomycotina, class Microbotryomycetes, family Camptobasidiaceae. The dataset of the sequences supported the recognition of three species: Camptobasidium gelus , Camptobasidium arcticum sp. nov. (ex-type strain EXF-12713) and Psychromyces glacialis gen. and sp. nov. (ex-type strain EXF-13111). Camptobasidium gelus was found in the Svalbard and Greenland samples, while representatives of the here proposed new species, C. arcticum , were found only in the Greenland Ice Sheet. Psychromyces gen. nov. was erected for the dimorphic/filamentous isolates found in Svalbard and Greenland glacial environments. The taxon, for which the invalid name ' Rhodotorula svalbardensis ' has been used, belongs to this genus. Based on ribosomal genes, Camptobasidium arcticum and Psychromyces glacialis are related, phylogenetically most closely related to the genera Glaciozyma and Cryolevonia . Seven genes phylogeny restricted to taxa with available sequences, supported the placement of Psychromyces to Camptobasidiaceae.

Published
2021
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30. Linking environmental prokaryotic viruses and their host through CRISPRs

Author

Laure Franqueville, Catherine Larose, Laura Sanguino, Timothy M. Vogel, Ampère, Département Bioingénierie (BioIng), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)

Subjects
glacial ice, viruses, Bacterial genome size, Environment, Applied Microbiology and Biotechnology, Microbiology, 03 medical and health sciences, Transduction (genetics), Ralstonia, RNA, Ribosomal, 16S, CRISPR, Bacteriophages, Clustered Regularly Interspaced Short Palindromic Repeats, Ice Cover, Ecosystem, Soil Microbiology, 030304 developmental biology, virus-host interactions, 0303 health sciences, Ecology, biology, CRISPRs, Bacteria, Base Sequence, 030306 microbiology, Arctic Regions, Norway, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Computational Biology, biology.organism_classification, transduction, The arctic, Arctic, Evolutionary biology, Metagenomics, Metagenome, Network approach, Genome, Bacterial, Virus Physiological Phenomena
Abstract

International audience; The ecological pressure that viruses place on microbial communities is not only based on predation, but also on gene transfer. In order to determine the potential impact of viruses and transduction, we need a better understanding of the dynamics of interactions between viruses and their hosts in the environment. Data on environmental viruses are scarce, and methods for tracking their interactions with prokaryotes are needed. Clustered regularly interspaced short palindromic repeats (CRISPRs), which contain viral sequences in bacterial genomes, might help document the history of virus-host interactions in the environment. In this study, a bioinformatics network linking viruses and their hosts using CRISPR sequences obtained from metagenomic data was developed and applied to metagenomes from Arctic glacial ice and soil. The application of our network approach showed that putative interactions were more commonly detected in the ice samples than the soil which would be consistent with the ice viral-bacterial interactions being more dynamic than those in soil. Further analysis of the viral sequences in the CRISPRs indicated that Ralstonia phages might be agents of transduction in the Arctic glacial ice.

Published
2015

31. Draft genome sequence of Dyadobacter tibetensis type strain (Y620-1) isolated from glacial ice

Author

Liang Shen, Nianzhi Jiao, Baiqing Xu, Ninglian Wang, Tandong Yao, Yongqin Liu, and Anyi Hu

Subjects
Genetics, Whole genome sequencing, geography, glacial ice, food.ingredient, geography.geographical_feature_category, draft genome, Strain (biology), Dyadobacter tibetensis, Glacier, Biology, medicine.disease_cause, Dyadobacter, Genome, Short Genome Reports, food, medicine, Glacial period, Gene, psychrotolerant bacterium
Abstract

Dyadobacter tibetensis Y620-1 is the type strain of the species Dyadobacter tibetensis, isolated from ice at a depth of 59 m from a high altitude glacier in China (5670 m above sea level). It is psychrotolerant with growth temperature ranges of 4 to 35°C. Here we describe the features of this organism, together with the draft genome sequence and annotation. The 5,313,963 bp long genome contains 4,828 protein-coding genes and 39 RNA genes. To the best of our knowledge, this is the first Dyadobacter strain that was isolated from glacial ice. This study provides genetic information of this organism to identify the genes linked to its specific mechanisms for adaption to extreme glacial environment.

Published
2014

32. Energy Reconstruction Methods in the IceCube Neutrino Telescope

Author

Aartsen, M. G., Abbasi, R., Baker, M., Heinen, D., Helbing, K., Hellauer, R., Hickford, S., Hill, G. C., Hoffman, K. D., Hoffmann, R., Homeier, A., Hoshina, K., Huang, F., Barwick, S. W., Huelsnitz, W., Hulth, P. O., Hultqvist, K., Hussain, S., Ishihara, A., Jackson, S., Jacobi, E., Jacobsen, J., Jagielski, K., Japaridze, G. S., Baum, V., Jero, K., Jlelati, O., Kaminsky, B., Kappes, A., Karg, T., Karle, A., Kauer, M., Kelley, J. L., Kiryluk, J., Kläs, J., Bay, R., Klein, S. R., Köhne, J -H, Kohnen, G., Kolanoski, H., Köpke, L., Kopper, C., Kopper, S., Koskinen, D. J., Kowalski, M., Krasberg, M., Beatty, J. J., Kriesten, A., Krings, K., Kroll, G., Kunnen, J., Kurahashi, N., Kuwabara, T., Labare, M., Landsman, H., Larson, M. J., Lesiak-Bzdak, M., Tjus, J Becker, Leuermann, M., Leute, J., Lünemann, J., Macías, O., Madsen, J., Maggi, G., Maruyama, R., Mase, K., Matis, H. S., McNally, F., Becker, K -H, Meagher, K., Merck, M., Meures, T., Miarecki, S., Middell, E., Milke, N., Miller, J., Mohrmann, L., Montaruli, T., Morse, R., BenZvi, S., Nahnhauer, R., Naumann, U., Niederhausen, H., Nowicki, S. C., Nygren, D. R., Obertacke, A., Odrowski, S., Olivas, A., Omairat, A., O'Murchadha, A., Berghaus, P., Paul, L., Pepper, J. A., Pfendner, C., Pieloth, D., Pinat, E., Posselt, J., Price, P. B., Przybylski, G. T., Quinnan, M., Rädel, L., Berley, D., Rameez, M., Rawlins, K., Redl, P., Reimann, R., Resconi, E., Rhode, W., Ribordy, M., Richman, M., Riedel, B., Robertson, S., Ackermann, Markus, Bernardini, E., Rodrigues, J. P., Rott, C., Ruhe, T., Ruzybayev, B., Ryckbosch, D., Saba, S. M., Sander, H -G, Santander, M., Sarkar, S., Schatto, K., Bernhard, A., Scheriau, F., Schmidt, T., Schmitz, M., Schoenen, S., Schöneberg, S., Schönwald, A., Schukraft, A., Schulte, L., Schulz, O., Seckel, D., Besson, D. Z., Sestayo, Y., Seunarine, S., Shanidze, R., Sheremata, C., Smith, M. W. E., Soldin, D., Spiczak, G. M., Spiering, C., Stamatikos, M., Stanev, T., Binder, G., Stanisha, N. A., Stasik, A., Stezelberger, T., Stokstad, R. G., Stößl, A., Strahler, E. A., Ström, R., Strotjohann, N. L., Sullivan, G. W., Taavola, H., Bindig, D., Taboada, I., Tamburro, A., Tepe, A., Ter-Antonyan, S., Tilav, S., Toale, P. A., Tobin, M. N., Toscano, S., Tselengidou, M., Unger, E., Bissok, M., Usner, M., Vallecorsa, S., Eijndhoven, N van, Overloop, A Van, Santen, J van, Vehring, M., Voge, M., Vraeghe, M., Walck, C., Waldenmaier, T., Blaufuss, E., Wallraff, M., Weaver, Ch, Wellons, M., Wendt, C., Westerhoff, S., Whelan, B., Whitehorn, N., Wiebe, K., Wiebusch, C. H., Williams, D. R., Blumenthal, J., Wissing, H., Wolf, M., Wood, T. R., Woschnagg, K., Xu, D. L., Xu, X. W., Yanez, J. P., Yodh, G., Yoshida, S., Zarzhitsky, P., Boersma, D. J., Ziemann, J., Zierke, S., Zoll, M., Bretz, Hans-Peter, Cruz Silva, Angel Humberto, van Santen, Jakob, Perez de los Heros, C., Tesic, G., Bohm, C., Adams, J., Bose, D., Böser, S., Botner, O., Brayeur, L., Brown, A. M., Bruijn, R., Casey, J., Casier, M., Chirkin, D., Christov, A., Aguilar, J. A., Christy, B., Clark, K., Classen, L., Clevermann, F., Coenders, S., Cohen, S., Cowen, D. F., Danninger, M., Daughhetee, J., Davis, J. C., Ahlers, M., Day, M., Clercq, C De, Ridder, S De, Desiati, P., de Vries, K. D., de With, M., DeYoung, T., Díaz-Vélez, J. C., Dunkman, M., Eagan, R., Altmann, D., Eberhardt, B., Eichmann, B., Eisch, J., Euler, S., Evenson, P. A., Fadiran, O., Fazely, A. R., Fedynitch, A., Feintzeig, J., Feusels, T., Arguelles, C., Filimonov, K., Finley, C., Fischer-Wasels, T., Flis, S., Franckowiak, A., Frantzen, K., Fuchs, T., Gaisser, T. K., Gallagher, J., Gerhardt, L., Auffenberg, J., Gladstone, L., Glüsenkamp, T., Goldschmidt, A., Golup, G., Gonzalez, J. G., Goodman, J. A., Góra, D., Grandmont, D. T., Grant, D., Gretskov, P., Bai, X., Groh, J. C., Groß, A., Ha, C., Ismail, A Haj, Hallen, P., Hallgren, A., Halzen, F., Hanson, K., Hebecker, D., Heereman, D., Physics, and Elementary Particle Physics

Subjects
Physics - Instrumentation and Detectors, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 7. Clean energy, Upper and lower bounds, Spectral line, IceCube Neutrino Observatory, IceCube, dE/dx detectors, Nuclear physics, MEDIA, DEPENDENCE, SOUTH-POLE, ddc:610, Neutrino detectors, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instrumentation, Mathematical Physics, Cherenkov radiation, Cherenkov detectors, Performance of High Energy Physics Detectors, Physics, Muon, High Energy Physics::Phenomenology, Observable, Instrumentation and Detectors (physics.ins-det), PERFORMANCE, Charged particle, Physics and Astronomy, High Energy Physics::Experiment, Neutrino, Astrophysics - Instrumentation and Methods for Astrophysics, physics, SYSTEM, GLACIAL ICE
Abstract

Accurate measurement of neutrino energies is essential to many of the scientific goals of large-volume neutrino telescopes. The fundamental observable in such detectors is the Cherenkov light produced by the transit through a medium of charged particles created in neutrino interactions. The amount of light emitted is proportional to the deposited energy, which is approximately equal to the neutrino energy for $\nu_e$ and $\nu_\mu$ charged-current interactions and can be used to set a lower bound on neutrino energies and to measure neutrino spectra statistically in other channels. Here we describe methods and performance of reconstructing charged-particle energies and topologies from the observed Cherenkov light yield, including techniques to measure the energies of uncontained muon tracks, achieving average uncertainties in electromagnetic-equivalent deposited energy of $\sim 15\%$ above 10 TeV., Comment: 21 pages, 23 figures. New version reflects referee comments. Accepted by J. Instrumentation

Published
2014

33. Microbial analyses of ancient ice core sections from greenland and antarctica

Author

Ram Veerapaneni, Scott O. Rogers, Tom D’Elia, and Caitlin N. Knowlton

Subjects
Cyanobacteria, glacial ice, Firmicutes, Greenland, Rhodotorula, General Biochemistry, Genetics and Molecular Biology, Article, Ice core, metagenomic, bacteria, lcsh:QH301-705.5, metatranscriptomic, geography, geography.geographical_feature_category, General Immunology and Microbiology, biology, Ecology, Glacier, Before Present, biology.organism_classification, Alternaria, Arid, cultures, Oceanography, lcsh:Biology (General), microbes, fungi, Antarctica, General Agricultural and Biological Sciences
Abstract

Ice deposited in Greenland and Antarctica entraps viable and nonviable microbes, as well as biomolecules, that become temporal atmospheric records. Five sections (estimated to be 500, 10,500, 57,000, 105,000 and 157,000 years before present, ybp) from the GISP2D (Greenland) ice core, three sections (500, 30,000 and 70,000 ybp) from the Byrd ice core, and four sections from the Vostok 5G (Antarctica) ice core (10,500, 57,000, 105,000 and 105,000 ybp) were studied by scanning electron microscopy, cultivation and rRNA gene sequencing. Bacterial and fungal isolates were recovered from 10 of the 12 sections. The highest numbers of isolates were found in ice core sections that were deposited during times of low atmospheric CO2, low global temperatures and low levels of atmospheric dust. Two of the sections (GISP2D at 10,500 and 157,000 ybp) also were examined using metagenomic/metatranscriptomic methods. These results indicated that sequences from microbes common to arid and saline soils were deposited in the ice during a time of low temperature, low atmospheric CO2 and high dust levels. Members of Firmicutes and Cyanobacteria were the most prevalent bacteria, while Rhodotorula species were the most common eukaryotic representatives. Isolates of Bacillus, Rhodotorula, Alternaria and members of the Davidiellaceae were isolated from both Greenland and Antarctica sections of the same age, although the sequences differed between the two polar regions.

Published
2012

34. Monitoring of Glaciers, Climate, and Runoff in the Hindu Kush-Himalaya Mountains

Author

Donald Alford, David Archer, Bodo Bookhagen, Wolfgang Grabs, Sarah Halvorson, Kenneth Hewitt, Walter Immerzeel, Ulrich Kamp, and Brandon Krumwiede

Subjects
CLIMATIC VARIABLES, HYDROLOGICAL REGIME, CLIMATE CHANGES, SEA ICE, REGIONAL CLIMATE CHANGE, RAINFALL DATA, LAND SURFACE, SURFACE AIR, CLIMATIC FACTORS, WARMING CLIMATE, RAIN DAYS, AERIAL PHOTOGRAPHY, HYDROMETEOROLOGY, CLIMATE VARIABLES, CLIMATE CHANGE ANALYSIS, AERIAL PHOTOGRAPHS, RAINFALL, SURFACE PARAMETERS, ICE COVER, ICE MASS, CLIMATE-CHANGE, AIR TEMPERATURE, GLACIAL LAKES, SEASONAL PRECIPITATION, CLIMATOLOGISTS, ICE STREAM, SCIENCE, TEMPORAL RESOLUTION, SUMMER MONSOON RAINFALL, TEMPERATURE CHANGE, SURFACE REFLECTANCE, METEOROLOGICAL ORGANIZATION, SCIENTIFIC ASSESSMENT, CLIMATE CYCLES, GLACIER INVENTORY, ICE VOLUME, CLIMATE NETWORKS, TEMPORAL VARIATIONS, CLIMATE CHANGE SCIENCE, ICE TONGUES, ICE CAPS, RAINFALL MEASUREMENT, CLIMATE MONITORING SYSTEMS, EXTREME CONDITIONS, HYDROLOGICAL BUDGET, NATIONAL METEOROLOGICAL SERVICES, METEOROLOGICAL STATIONS, CLIMATE SYSTEMS, TEMPERATURE FLUCTUATIONS, HYDROLOGICAL RECORDS, REGIONAL CLIMATE, CONVECTIVE RAINFALL, CLIMATE MODELS, MEAN TEMPERATURE, HYDROLOGICAL CYCLE, INTERGOVERNMENTAL PANEL ON CLIMATE CHANGE, CLIMATE MONITORING, CLIMATES, HYDROLOGY, CLIMATE CHANGE IMPLICATIONS, HYDROLOGICAL REGIMES, ICE MELTING, CLIMATIC BEHAVIOR, GLACIERS, CLIMATE RESEARCH, GLACIER AREA, METEOROLOGICAL OBSERVATIONS, TEMPORAL VARIATION, SURFACE MELTING, SURFACE ALBEDO, METEOROLOGICAL SERVICES, SURFACE ROUGHNESS, RAINY DAYS, RAIN, GLOBAL CLIMATE, ICE AGE, MINIMUM TEMPERATURE, METEOROLOGICAL DATA, SUMMER TEMPERATURE, LOCAL TEMPERATURE, RESPONSE TO CLIMATE CHANGE, HYDROLOGICAL PROCESSES, SCIENTISTS, CLIMATIC VARIABILITY, RAINFALL TREND, SUMMER TEMPERATURES, SURFACE TEMPERATURE, CLIMATE TRENDS, CLIMATE DATA, HYDROLOGICAL RESPONSE, HYDROLOGICAL DATA, GLACIAL ICE, IMPACT OF CLIMATE, INCREASE IN TEMPERATURE, CLIMATIC CHANGE, CONVENTION ON CLIMATE CHANGE, CLIMATE STATIONS, CLIMATE RESEARCH UNIT, CLIMATE CHANGE, DAILY TEMPERATURE, SEASON, GLACIER RETREAT, WIND SPEED, AVERAGE RAINFALL, REGIONAL CLIMATES, CLIMATE VARIABILITY, SURFACE AIR TEMPERATURE, GLOBAL CLIMATE CHANGE, TEMPERATURES, CLIMATE CHANGE CHALLENGES, CLOUD TOP TEMPERATURE, TEMPERATURE, SURFACE LAYERS, IMPACT OF CLIMATE CHANGE, ENVIRONMENTAL SCIENCE, TEMPERATURE INCREASES, GLOBAL CLIMATE OBSERVING SYSTEM, CLIMATIC INFORMATION, CLIMATIC FLUCTUATIONS, RAINFALL–RUNOFF, AIR, GLACIER MELTING, CLOUDS, MINIMUM TEMPERATURES, HYDROLOGICAL SCIENCES, SEASONAL TEMPERATURE, CLIMATE FORCING, MAXIMUM TEMPERATURE, ICE MASSES, CLIMATE VARIATIONS, TEMPERATURE RECORD, SURFACE MODELS, GLACIER MELT, CLOUD COVER, INTENSE RAINFALL, GLOBAL TEMPERATURE, CLIMATOLOGY, SCIENTIFIC STUDY, TEMPORAL PATTERNS, ATLANTIC OCEAN, CLIMATE CHANGE IMPACTS, CLIMATE CHANGE STUDIES, CLIMATE ANALYSIS, FRAMEWORK CONVENTION ON CLIMATE CHANGE, HYDROLOGICAL MODELS, GLOBAL CLIMATIC CHANGE, CLIMATE SYSTEM, TEMPERATURE CHANGES, GLACIAL LAKE, COLD CLIMATES, METEOROLOGY, GLACIAL LAKE OUTBURST, OCEANS, RAINFALL DISTRIBUTION, SURFACE ELEVATION, METEOROLOGICAL VARIABLES, CLIMATIC GRADIENTS, TEMPERATURE RECORDS, CLIMATIC RECORD, CLIMATE CHANGE ADAPTATION, RAINFALL INTENSITY, HYDROLOGICAL SYSTEMS, SEASONS, SURFACE ENERGY, CLIMATE CHANGE SCENARIOS, GLACIER MELT RUNOFF, TEMPERATURE DATA, CLIMATE DYNAMICS, ASSESSMENT OF CLIMATE CHANGE, CLIMATIC RECORDS, LAND SURFACE MODELS, SCIENTIST, ICE, ICE STREAMS, RAINFALL RUNOFF, WIND, CLOUDY CONDITIONS, AIR MASS, SUMMER RAINFALL, MOUNTAIN GLACIERS, CLIMATE, CLIMATE ACTION, ICE MELT, IMPACTS OF CLIMATE CHANGE, SOLAR RADIATION, TEMPERATURE RANGE, CLIMATE VARIATION
Abstract

Hydrometeorological monitoring, as discussed here, describes the activities required to characterize the properties and processes of the hydrosphere as it exists in the three-dimensional mesoscale environment of the high-mountain catchment basins of the Hindu Kush-Himalaya (HKH) Mountains. Credible monitoring involves: (a) functional institutions; (b) operational instruments; (c) trained, motivated individuals; (d) scientific procedures; and (e) dedicated funding. Establishing a regional hydro-meteorological research facility in the HKH Mountains will involve developing solutions in the areas of integrated data collection and analysis procedures, instrument selection and placement, compatibility of monitoring instruments and procedures, training of personnel, procedures related to scale and modeling, ensuring accessibility of monitoring sites, and management, analysis, and archiving of the acquired data, all in the context of processes within the mountain basins, not in the adjacent lowlands. Mountain hydrometeorology is defined by a set of complex, three-dimensional, biophysical environments, produced by interactions among terrain, geology, and meteorology. The homogeneity seen from the distant lowlands becomes a complex mosaic of environments within the headwater basins. Altitude determines the properties of an atmospheric column extending upwards from a point within the mountains. These atmospheric properties determine the potential water and energy budgets at a point, or within a basin, in the mountains. Relief, slope aspect and angle, defines local topography.

Published
2012

35. Comparison of impact forces measured by different instrumentation systems on CCGS Terry Fox during the Bergy Bit Trials

Author

M. Johnston, Robert E. Gagnon, and Ron Ritch

Subjects
Engineering, Inertial frame of reference, business.industry, Instrumentation, MOTAN, Structural engineering, Impact test, Geotechnical Engineering and Engineering Geology, Collision, Bit (horse), Acceleration, Impact Panel, Bergy Bit Trials, Hull, Impact Forces, Forensic engineering, General Earth and Planetary Sciences, Glacial Ice, business, Strain gauge
Abstract

A comparison of the forces that were measured by different instrumentation systems during a number of ship collisions with bergy bits is presented. Three types of instruments were used to measure ship impact forces: an inertial measurement system called MOTAN, a 5.4 m2 strain gauged area and a 3.5 m2 external Impact Panel. Forces on the Impact Panel were consistently lower than forces on the strain gauged area, for different impacts. The maximum force on the Impact Panel was 1.2 MN, and the highest force on the strain gauged area was 5.1 MN. Forces from MOTAN are calculated using two different approaches; one requires information about where the impact occurred, and the other does not. The agreement in forces from MOTAN and the strain gauged area or Impact Panel depended upon how completely the hull instrumentation captured the loaded area. When the strain gauged area provided good coverage of the loaded area (7 impacts), forces from MOTAN were from 17% lower to 33% higher than forces on the strain gauged area, if the impact location was used to calculate the forces. When the impact location was not used in the calculation, forces from MOTAN were up to 120% higher than forces on the strain gauged area. The four most significant impacts to the Impact Panel, all of which extended beyond the Panel's sensing area, indicated that forces from MOTAN were from 11% lower to 233% higher than forces on the Impact Panel.

Published
2008

36. Analysis of microbes in Greenland ice cores from periods of high and low atmospheric carbon dioxide levels

Author

Knowlton, Caitlin N.

Subjects
Microbiology, Molecular Biology, Bioinformatics, glacial ice, Greenland, metagenomic, metatranscriptomic, microbes, bacteria, bioinformatics, carbon dioxide
Abstract

Glacial ice entraps microbial cells and nucleic acids that have been deposited from the atmosphere by precipitation or on dust particles carried by the wind. The ice is deposited in sequential layers representing distinct past periods of time. Metagenomics and metatranscriptomics offer means to perform comprehensive analyses of microbial genes and taxa within the ice. During the past 400,000 years, fluctuations in atmospheric carbon dioxide levels have directly coincided with temperature fluctuations. Three ice core sections from Byrd Station, Antarctica (80° 1’ S, 119° 31’ W) and three ice core sections from GISP 2D (Greenland Ice Sheet Project, core 2D; 72o 36' N, 38o 30'W) were aseptically melted. Two of the ice core sections from GISP 2D (at 1600 m = 10,500 ybp [years before present] and at 3014 m = 157,000 ybp) were analyzed using metagenomic and metatranscriptomic analyses. The 157,000 year old ice core section was deposited during low atmospheric CO2 levels that would have led to low temperatures, low precipitation rates, and high dust levels, while the 10,500 year old core section was deposited during high CO2 levels that would have led to higher temperatures, higher precipitation rates, and lower dust levels. Nucleic acids from ultracentrifuge-concentrated meltwater were subjected to 454 pyrosequencing. Taxonomic analyses were based on rRNA and mRNA sequences. Taxa in the 10,500 ybp ice primarily included bacterial species of Proteobacteria, Firmicutes, and Cyanobacteria. This sample also contained black particulate matter indicative of volcanic activity. Major volcanic activity was reported in Iceland, Alaska, and from a super volcano in Italy during the 10,500 ybp time period. The 157,000 ybp sample also contained a large number of Proteobacteria and Firmicute species, a few Actinobacteria and Cyanobacteria, but most were common soil bacteria, as well as animal pathogens. The number and frequency of cyanobacterial species was much higher. While some species were in common to both samples, a large number of unique taxa and genes were present in each of the samples. These unique taxa and genes suggest different atmospheric conditions may influence the deposition of microbes in ice.

Published
2013

37. IDENTIFICATION AND COMPARISION OF FUNGI FROM DIFFERENT DEPTHS OF ANCIENT GLACIAL ICE

Author

Patel, Angira N.

Subjects
Biology, Molecular, Fungi, Glacial ice, Microorganisms, Greenland, Antarctica
Abstract

Glacial ice serves as a unique preservation matrix for contemporary and ancient microorganisms. The main objective of this study was to evaluate and test the existence of the fungi encased in ancient glacial ice of Antarctica and Greenland. PCR (polymerase chain reaction) amplification was used to isolate the DNA followed by DNA sequencing to obtain the DNA sequences of the ancient microorganisms. Most of the sequences obtained from ancient microbes were similar to the contemporary fungi. Few fungi cultured were approximately 10,000 years old. Microorganisms isolated from ancient glacial ice have undergone repeated phases of evolutionary changes, such as irradiation, freezing and thawing, and in the process they have been archiving various biogenic materials over the period of time. These microorganisms entrapped in glacial ice provide valuable information about the evolutionary processes, as well as the rich biodiversity during ancient times. Hence, various species of microorganisms may appear to be extinct, but factually they might be dormant, entrapped in ice for millions of years and are capable to reappear amidst suitable conditions. The results of this study can be used in future to relate the biological, biogeochemical and genetic composition to a unique and well characterized geologic history of the fungi entrapped in ancient glacial ice.

Published
2006

38. Detection, recovery, isolation, and characterization of bacteria in glacial ice and Lake Vostok accretion ice

Author

Christner, Brent C.

Subjects
Biology, Microbiology, microbial survival, glacial ice, extreme environment, exobiology, Lake Vostok
Abstract

An extraction system has been constructed that melts ice from the interior of ice cores and collects the resulting melt water aseptically. Using this system, bacteria entrapped in modern and ancient glacial ice from worldwide locations and in an ice core extending into accreted Lake Vostok ice have been isolated using enrichment culture and identified by amplification and sequencing of DNA-encoding 16S rRNA genes. In general, ice cores from non-polar locations contained larger numbers and species of cultivable bacteria than samples from polar ices, presumably due to the closer proximity of terrestrial biological ecosystems and exposed landscape. When compared with other polar locations, higher numbers of isolates were obtained from ices adjacent to the Dry Valley complex of Antarctica, consistent with the influx of airborne biological particles from local environments serving as the primary factor controlling the numbers of microorganisms present. The numbers of recoverable bacteria did not correlate directly with the age of the ice, and isolates were recovered from the oldest samples examined (>500K years old). The 16S rDNA sequences from bacterial isolates and amplicons obtained directly from samples position within 6 different bacterial lines of descent (alpha, beta, and gamma-proteobacteria, high and low G+C gram positive bacteria, and the Cytophaga/Flavobacterium/Bacteroides). Some of the isolated bacteria have close phylogenetic relationships with species originating from permanently cold environments, and other ice core sites or different portions (time periods) of the same core. Macromolecular synthesis was demonstrated in bacteria frozen under conditions analogous to those in glacial ice, and the possibility exists that metabolic activity and repair may occur during extended periods of glacial entrapment. Several of the species identified in Lake Vostok accretion ice are also related to glacial isolates and species from other cold environments. These ice core studies have provided a glimpse of the microorganisms likely to inhabitant this potentially unique subsurface ecosystem. Investigating microbial survival in ice and exploring potential habitats for activity within the glacial and subglacial environment has confirmed that these could have served as refuge environments for life during periods of global glaciation (Snowball Earth), and has provided data for extrapolations to the likelihood of microorganisms surviving frozen in extraterrestrial habitats or during interplanetary transport.

Published
2002

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