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Relevant bibliographies by topics / Icecore

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Academic literature on the topic 'Icecore'

Author: Grafiati

Published: 9 March 2023

Last updated: 10 March 2023

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Journal articles on the topic "Icecore"

1

Bush, Elizabeth. "Icecore: A Carl Hobbes Thriller (review)." Bulletin of the Center for Children's Books 61, no. 6 (2008): 270. http://dx.doi.org/10.1353/bcc.2008.0068.

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Siggaard-Andersen, Marie-Louise, Jørgen Peder Steffensen, and Hubertus Fischer. "Lithium in Greenland ice cores measured by ion chromatography." Annals of Glaciology 35 (2002): 243–49. http://dx.doi.org/10.3189/172756402781816483.

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AbstractIon chromatography (IC) is a widely used technique for analyzing ice cores for ions like Na+, NH4+, K+, Mg2+, Ca2+, F–, MSA–, Cl–, NO2– and SO42– that are present in polar ice cores at ppb level. By using sample preconcentration and an optimized separation technique, we have been able to detect Li+ in ice-core samples in concentrations as low as 0.0001 μeq kg–1 or 0.7 ppt by IC. During routine analysis of ions in ice cores, the lithium content has been evaluated and recorded. the IC technique used in these measurements and some exemplary IC data from the Greenland Icecore Project (GRIP) and the North Greenland Icecore Project (NorthGRIP) ice cores are presented. By these data we introduce Li+ concentration as a new parameter in the analysis of ice cores. Like other ions, Li+ reflects climatic changes and shows seasonal cycles. on the basis of the geochemistry of lithium, we suggest that Li+ measured in the Greenland ice cores is derived from mineral dust. However, data from the NorthGRIP ice core representing the 8.2 kyr BPHolocene cold event show a strong Li+ signal that does not correlate with any other ionic component measured. This means that the lithium content in ice cores is a signal with its own pattern, which is not yet understood.

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Dahl-Jensen, Dorthe, Niels S. Gundestrup, Heinz Miller, Okitsugu Watanabe, Sigfús J. Johnsen, Jørgen P. Steffensen, Henrik B. Clausen, Anders Svensson, and Lars B. Larsen. "The NorthGRIP deep drilling programme." Annals of Glaciology 35 (2002): 1–4. http://dx.doi.org/10.3189/172756402781817275.

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AbstractThe North Greenland Icecore Project (NorthGRIP) was initiated in 1995 as a joint international programme involving Denmark, Germany, Japan, Belgium, Sweden, Iceland, the U.S.A., France and Switzerland. the main goal was to obtain undisturbed high-resolution information about the Eemian climatic period (115–130 kyr BP). the records from the Greenland Icecore Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) in central Greenland are different and disturbed down in the ice covering this period. Internal radio-echo sounding layers show that NorthGRIP, placed 325 km north-northwest of GRIP at the Summit of the Greenland ice sheet, is located on a gently sloping ice ridge with very flat bedrock and internal layers found so high that an undisturbed Eemian record is possible. Internal layers much farther above bedrock than their apparent counter parts at GRIP suggest that conditions are favourable for recovery of an undisturbed Eemian record. So far, a 1351 mdeep ice core (NorthGRIP1) and a 3001 mdeep ice core (NorthGRIP 2) have been recovered. the ice thickness is expected to be 3080 m, and the ice temperature at 3001 m is –5.6°C, so we expect basal melting at the bedrock. Most of the Eemian ice will be melted away, leaving only the last part and the transition between the Eem and the Last Glacial Period. At 3001 m the age of the ice is 110 kyr BP and the annual layers are of the order 1 cm.With modern methods the annual layers can be resolved, resulting in detailed information on the decline of the warm Eemian period into the Last Glacial Period.

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Mathiesen, Joachim, Jesper Ferkinghoff-Borg, Mogens H. Jensen, Mogens Levinsen, Poul Olesen, Dorthe Dahl-Jensen, and Anders Svensson. "Dynamics of crystal formation in the Greenland NorthGRIP ice core." Journal of Glaciology 50, no. 170 (2004): 325–28. http://dx.doi.org/10.3189/172756504781829873.

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AbstractThe North Greenland Icecore Project (NorthGRIP) palaeoclimatic information back to about 120 kyr BP. The size distributions of ice crystals in the upper 880 m of the NorthGRIP ice core, which cover a time-span of approximately 5300 years, have been obtained previously. The distributions evolve towards a universal curve, indicating a common underlying physical process in the formation of crystals. We identify this process as an interplay between fragmentation of the crystals and diffusion of their grain boundaries. The process is described by a two-parameter differential equation to which we obtain the exact solution. The solution is in excellent agreement with the measured distributions.

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Thomas, Elizabeth R., Robert Mulvaney, and Eric W. Wolff. "A change in seasonality in Greenland during a Dansgaard–Oeschger warming." Annals of Glaciology 48 (2008): 19–24. http://dx.doi.org/10.3189/172756408784700590.

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AbstractA new sub-seasonal chemical record is presented from the North Greenland Icecore Project (NorthGRIP) ice core during the onset of one of the longest and strongest interstadials of the last glacial period, Dansgaard–Oeschger event 8 (approximately 38 000 years ago). This is the first time that a record of such resolution has been achieved over several metres of deep glacial ice and provides a unique opportunity for using additional parameters to carry out accurate dating using annual-layer counting. The very high-resolution chemical data were used to assess the phasing of various ions and determine changes in the seasonal strength of chemical deposition and the shape of the seasonal cycle. The study shows that a change in seasonality accompanied the dramatic warming transition from stadial to interstadial conditions in Greenland.

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Hvidberg, Christine Schøtt, Kristian Keller, and Niels S. Gundestrup. "Mass balance and ice flow along the north-northwest ridge of the Greenland ice sheet at NorthGRIP." Annals of Glaciology 35 (2002): 521–26. http://dx.doi.org/10.3189/172756402781816500.

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AbstractThe North Greenland Icecore Project (NorthGRIP) deep drilling site (75˚05’47’’N, 42˚19’42’’ W) is located at the north-northwest ridge of the Greenland ice sheet, 320 km from Summit. A strain net has been established around the NorthGRIP site and surveyed with global positioning system. Our results show that ice flows with a horizontal surface velocity of 1.329 ±0.015ma–1 along the ridge. Estimated principal surface strain rates at NorthGRIP are and in the directions along and transverse to the north-northwest ridge, respectively, i.e. ice is compressed along the ridge but stretched transverse to the ridge. Possible implications of the observed flow pattern for the stratigraphy are discussed. the average thickening rate in the strain-net area is found to be ∂H/∂t = 0.00 ±0.04ma– 1, in agreement with previous estimates of mass balance in high-elevation areas of Greenland.

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Svensson, Anders, Karen G. Schmidt, Dorthe Dahl-Jensen, Sigfús J. Johnsen, Yun Wang, Sepp Kipfstuhl, and Thorsteinn Thorsteinsson. "Properties of ice crystals in NorthGRIP late- to middle-Holocene ice." Annals of Glaciology 37 (2003): 113–18. http://dx.doi.org/10.3189/172756403781815636.

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AbstractDetailed measurements of crystal outlines and fabrics have been performed on 35 000 crystals in fifteen 10 × 20 cm2 vertical thin sections from the North Greenland Icecore Project (NorthGRIP) ice core, evenly distributed in the depth interval 115–880m. The crystals exhibit important changes over this period. As the ice gets older the mean crystal area increases towards a constant value, the shape of the crystals becomes increasingly irregular, and the area distribution of crystals develops from a single log-normal distribution into a bimodal lognormal distribution. The c-axis fabric of the ice shows a smooth development of an increasingly stronger vertical fabric with depth, and the formation of a weak vertical girdle. Already in the younger samples the fabric is rather strongly oriented towards vertical. The fabric and the area of individual crystals are found not to correlate. A simple model, which takes into account the vertical strain of the ice, is applied in an attempt to determine the crystal growth rate at NorthGRIP.

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Hvidberg, Christine Schøtt, Jørgen Peder Steffensen, Henrik B. Clausen, Hitoshi Shoji, and Joseph Kipfstuhl. "The NorthGRIP ice-core logging procedure: description and evaluation." Annals of Glaciology 35 (2002): 5–8. http://dx.doi.org/10.3189/172756402781817293.

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AbstractThe ice-core logging procedure used to log the North Greenland Icecore Project (NorthGRIP) ice cores is described. the existence of two deep ice cores, NorthGRIP 1and 2, drilled 25 mapart, allows an independent evaluation of the procedure. the logged depths of the NorthGRIP 1 and 2 cores deviate from the length of the unwound drill cable corrected for elongation of the cable when hanging in the hole, by 1.5‰ and 50.5‰ at depths of 1371 and 2931 m, respectively. Differences between logged depths of identified layers found in both cores are studied in the depth interval where they overlap. Layers are identified by electrical conductivity measurements and dielectric profiling. the difference between the logged depths of layers identified in both cores increases to 0.5 m close to the bottom of the NorthGRIP 1 core, which is <0.5 mm m–1 ice core. the comparison between the two cores shows that the NorthGRIP logging procedure is accurate and reproducible. Further, our results show that the temperature conditions and handling of the core during logging are important for obtaining a precise depth.

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Dahl-Jensen, Dorthe, Niels Gundestrup, S. Prasad Gogineni, and Heinz Miller. "Basal melt at NorthGRIP modeled from borehole, ice-core and radio-echo sounder observations." Annals of Glaciology 37 (2003): 207–12. http://dx.doi.org/10.3189/172756403781815492.

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AbstractFrom temperature measurements down through the 3001 m deep borehole at the North Greenland Icecore Project (NorthGRIP) drill site, it is now clear that the ice at the base, 3080 m below the surface, is at the pressure-melting point. This is supported by the measurements on the ice core where the annual-layer thicknesses show there is bottom melting at the site and upstream from the borehole. Surface velocity measurements, internal radio-echo layers, borehole and ice-core data are used to constrain a time-dependent flow model simulating flow along the north-northwest-trending ice-ridge flow-line, leading to the NorthGRIP site. Also time-dependent melt rates along the flowline are calculated with a heat-flow model. The results show the geothermal heat flow varies from 50 to 200 mW m–2 along the 100km section of the modeled flowline. The melt rate at the NorthGRIP site is 0.75 cm a–1, but the deep ice in the NorthGRIP core originated 50 km upstream and has experienced melt rates as high as 1.1 cm a–1.

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Svensson, Anders, Pauli Baadsager, Asbjørn Persson, Christine Schøtt Hvidberg, and Marie-Louise Siggaard-Andersen. "Seasonal variability in ice crystal properties at NorthGRIP: a case study around 301 m depth." Annals of Glaciology 37 (2003): 119–22. http://dx.doi.org/10.3189/172756403781815582.

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AbstractThe aim of this case study is to quantify the seasonal variability in crystal properties and to discuss the reason for the variability. A continuous 1.10 m long vertical thin-section profile covering approximately five annual cycles has been obtained from the North Greenland Icecore Project (NorthGRIP) ice core at around 301 m depth. The crystal outline and the c-axis orientation of more than 13000 crystals in the profile have been measured on a new Australian automated ice-crystal analyzer. In 2.5 cm resolution we observe a strong seasonal variability in crystal areas of >30%deviation from the average value of 6.7 mm2. Each year, a band of smaller crystals is observed in ice deposited during spring. The area distribution function is found to be close to a lognormal distribution. The crystal areas are compared to the concentration of chemical impurities in the ice; at a 5 cm resolution, the best correlation is found with the concentration of Ca2+. Our results show no seasonal variability of the average c-axis orientation of ice crystals.

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Dissertations / Theses on the topic "Icecore"

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Santanam, Suresh. "A trend study of atmospheric methane : 1965-81 GC and polar icecore measurements /." Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,168.

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GARZONIO, ROBERTO. "Modelling the suitability for ice core drilling of mountain glaciers and development of new spectroscopy systems for cold room laboratory and environmental monitoring." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/102667.

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I ghiacciai montani sono importanti fonti di dati paleoclimatici, essenziali allo studio dei cambiamenti climatici e ambientali. L'aumento della fusione dei ghiacciai sta portando alla perdita di preziose informazioni utili a predire l’evoluzione del clima. In questo contesto, è fondamentale definire le linee guida e creare mappe per l’identificazione delle aree idonee ad essere perforate. Nel primo anno di dottorato, ho definito l’idoneità di un ghiacciaio alla perforazione (SICD) come la probabilità di estrarre un campione di ghiaccio che possiede una stratigrafia ben conservata, utile alla ricostruzione del clima del passato. Le varabili ambientali introdotte nel modello, relazionate con la perforabilità, sono state selezionate in accordo alle perforazioni già effettuate, e alla letteratura scientifica, considerando l’opinione degli esperti. Due modelli spaziali sono stati sviluppati: il promo basato sulla conoscenza di esperti, il secondo di tipo probabilistico. Le variabili scelte (pendenza, rilievo locale, temperatura, radiazione solare diretta) sono state così combinate al fine di mappare le aree potenzialmente perforabili presenti nelle Alpi e in Asia. L’accuratezza del modello è stata valutata e sono state indicati i siti più idonei ad essere perforati. La ricerca ha permesso di fornire preziose informazioni utili alla scelta dei prossimi siti di perforazione. Nel secondo anno di dottorato un Sistema Aeromobile a Pilotaggio Remoto (SAPR) è stato sviluppato per acquisire misure spettrali durante campagne di spettroscopia di campo. Il sistema, nominato HyUAV, è basato su una piattaforma APR equipaggiata con uno spettrometro e una camera RGB. HyUAV è in grado di acquisire simultaneamente dati iperspettrali (350-1000 nm, 1.5 nm di risoluzione spettrale) della radiazione riflessa dalla Terra e immagini RGB. Un’ottica specifica (EOR) è stata sviluppata al fine di ottimizzare il campo di vista dello spettrometro e di misurare il segnale di Durk Current durante il volo. Le performance geometriche, radiometriche e spettrali del sistema sono state caratterizzate attraverso alcuni test di laboratorio ed è stata valutata l’accuratezza e la precisione dei dati iperspettrali raccolti attraverso un test di volo. Due metodi per la stima della riflettanza da UAV sono stati proposti e discussi. I risultati raggiunti mostrano: i) un’ottima stabilità del sistema (in termini geometrici, radiometrici e spettrali); ii) misure spettrali accurate (sia in termini di radianza che di riflettanza); iii) risultati simili tra i due metodi di stima della riflettanza. Lo studio ha dimostrato che il sistema HyUAV può essere considerato affidabile al fine di supportare indagini di spettroscopia di campo e promettente per un'ampia gamma di applicazioni ambientali. La spettroscopia ad immagine è una tecnica efficace che fornisce importanti informazioni per la caratterizzazione delle proprietà ottica delle superfici a scala spaziale di dettaglio. Applicata all’analisi delle carote di ghiaccio, essa può essere considerata una tecnica innovativa utile a migliorare la conoscenza dei cambiamenti climatici. Durante il terzo anno di dottorato, ho sviluppato un sistema automatico per acquisire immagini iperspettrali (HYCE) in camera fredda. Il sistema è composto da una un motore lineare ad alta precisione spaziale, il quale trasporta uno spettrometro iperspettrale ad immagine (Headwall Photonics VINR, 380-1000 nm, 2-3 nm di risoluzione spettrale, 1004 pixels spaziali) e una lampada alogena dedicata. Test di laboratorio sono stati effettuati al fine di valutare le componenti del sistema. Le prime immagini iperspettrali di una carota di ghiaccio sono state acquisite in camera fredda ed analizzate. In particolare è stato calcolato lo Snow Darkening Index (SDI) ed è stata verificare la sua applicabilità per la stima delle concentrazione di deposizioni atmosferiche minerarie nelle carote di ghiaccio.
Mountain glaciers and non-polar ice cores are very detailed sources of paleo-proxy data essential to achieve a complete overview of climate and environmental change. The increase in the glaciers melting leads to a loss of information, affecting the possibility to predict the climate evolution. In this context, is important to define a set of guidelines and create dedicated maps to identify suitable glaciers for ice core drilling. In the first year of the research, the Suitability for Ice Core Drilling (SICD) was defined as the likelihood of drilling a glacier to retrieve an ice core with preserved stratigraphic information that allows the reconstruction of historical climate conditions. Environmental variables related to the SICD were selected on the basis of previously drilled sites, according to available scientific literature and on the base of glaciologists opinions. A quantitative Weight of Evidence method was implemented and key variables (slope, local relief, temperature and direct solar radiation) are combined to map the potential drilling sites in the European Alps and in the Asian High Mountain glaciers. Accuracy is evaluated and first indications of potential drilling sites are reviewed. Results are valuable for future selection of potential drilling sites of mountain glacier. In the second year of the PhD, a light UAV for collecting spectral measurements was developed in support of field spectroscopy surveys. The system, namely HyUAV, is based on a four-rotors platform with hovering capability, equipped with a non-imaging spectrometer and a RGB camera. The HyUAV collects simultaneously hyperspectral data (350-1000 nm, ~1.5 nm spectral resolution) of Earth reflected radiance and RGB images. The Entrance Optics Receptor (EOR) was specifically developed to optimize the spectrometer field of view and to collect in-flight dark current. The geometric, radiometric and spectral performances of the system were characterized through dedicated laboratory tests. Then, the accuracy of the hyperspectral data were evaluated during flight tests, comparing spectral data collected from HyUAV with ground-based measurements. Two methods to estimate surface reflectance from HyUAV were investigated and discussed, with the aim of providing further suggestions for an accurate retrieval of surface reflectance. The results achieved shown: i) good systems stability of the system (in terms of geometric, radiometric and spectral features); ii) accurate spectra measurements (in terms of radiance and reflectance); iii) similar results for the delineated methods to calculate reflectance. The HyUAV demonstrated to be a reliability systems for supporting field spectroscopy surveys and a promising platform for a wide range of environmental applications. Imaging spectroscopy is a powerful technique that provides insights information, with the aim to investigate spectral features, related to surfaces properties and materials composition, at very detailed spatial resolution. Applied to ice cores analysis hyperspectral imaging, it can be considered an innovative technique, that could provide valuable information improving the understanding of climate change. During the third year of PhD, a fully automated Hyperspectral systems for Imaging Ice core (HyIICE) was developed in a cold-room environment. The HyIICE is composed by an high-precision linear stage, which embeds a imaging hyperspectral sensor (Headwall Photonics VINR spectrometer, 380-1000 nm, 2-3 nm spectral resolution, 1004 spatial pixels) and a dedicated stable halogen light source. Several tests were performed on the system to evaluate the components and verify the efficiency in cold environments. First hyperspectral imaging of ice cores were collected in order to inspecting the potential of hyperspectral imaging for the quantitative estimation of parameters related to past atmospheric and climate conditions.

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Silverwood, Hamish George Miles. "Supersymmetric Dark Matter in IceCube." Thesis, University of Canterbury. Physics and Astronomy, 2012. http://hdl.handle.net/10092/6927.

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The Minimally Supersymmetric Standard Model (MSSM) provides us with a WIMP dark matter candidate particle, the neutralino. Neutralinos from the dark matter halo can potentially become captured by the sun and concentrated in the core, where they can undergo self-annihilation and so produce a distinct neutrino signal. The IceCube Neutrino Observatory has the potential to detect this neutrino signal and thus give indirect evidence of the presence and properties of neutralino dark matter. Although the full, unconstrained MSSM has 105 parameters this can be reduced to 25 parameters by the application of physically motivated assumptions. Scans of this MSSM-25 parameter space are conducted using the DarkSUSY software package and an adaptive scanning technique based on the Monte-Carlo VEGAS algorithm. The IceCube exclusion confidence level is then calculated for a set of points produced by these scans. Results indicate that the detection capability of IceCube exceeds that of current direct detection methods in certain regions of the parameter space. The use of a 25 dimensional parameter space reveals that there are new regions of observables with high exclusion confidence levels compared to earlier simulations performed with a seven dimensional parameter space.

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Stachurska, Juliana. "Astrophysical Tau Neutrinos in IceCube." Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21611.

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Das IceCube Neutrino Observatorium am Südpol hat die Existenz eines diffusen astrophysikalischen Neutrinoflusses nachgewiesen. Die Flavor-Zusammensetzung astrophysikalischer Neutrinos trägt Informationen über Orte kosmischer Teilchenbeschleunigung und Auswirkungen potenzieller neuer Physik auf die Neutrinoausbreitung. Zur seiner Bestimmung ist die Beobachtung von Tau-Neutrinos nötig. Ab einer Energie von ~O(100 TeV) kann deren Wechselwirkung über geladene Ströme eine Doppelkaskaden-Topologie ergeben, bei der die zwei Energiedepositionen am Tau-Entstehungs- und Tau-Zerfallsvertex aufgelöst werden können. Diese wird zusammen mit den bereits bekannten Topologien Einzel-Kaskade und Spur zur Messung der Flavor-Zusammensetzung auf der Erde benutzt. In dieser Arbeit werden im Detektorvolumen von IceCube anfangende Ereignisse mit hohen Energien algorithmisch in drei Topologien klassifiziert. Im Datensatz mit einer Lebensdauer von 7.5 Jahren werden zum ersten Mal zwei Doppelkaskaden identifiziert; diese sind Kandidaten für Tau-Neutrinos. Die Eigenschaften der zwei Tau-Neutrino-Kandidaten werden in einer a-posteriori Analyse im Detail studiert. Die statistische Methode wird durch einen Log-Likelihood-Quotienten-Test mit multi-dimensionalen Wahrscheinlichkeitsdichten verbessert. Eine der Doppelkaskaden ist konsistent mit dem Szenario einer misklassifizierten Einzelkaskade, während für die zweite Doppelkaskade die Wahrscheinlichkeit eines nicht-Tau-Neutrino Szenarios auf nur 3% bestimmt wird. Die gemessene Flavor-Zusammensetzung ist konsistent mit der Annahme von astrophysikalischen Neutrinos sowie mit bisher veröffentlichen Resultaten. Die Messung ergibt einen astrophysikalischen Tau-Neutrino Fluss von dPhi / dE=3.0 (-1.8,+2.2) (E / 100TeV)^(-2.87) 10^(-18) GeV^(-1) cm^(-2) s^(-1) sr^(-1), was dem ersten positiven Ergebnis für die Tau-Normalisierung entspricht. Die Nichtexistenz eines astrophysikalischen Tau-Neutrino Flusses wird mit einer Signifikanz von 2.8 sigma abgelehnt.
The IceCube neutrino observatory at the South Pole has confirmed the existence of a diffuse astrophysical neutrino flux. The flavor composition of astrophysical neutrinos carries information on the environments at the sites of cosmic particle acceleration as well as potential imprints of new physics acting during neutrino propagation. To measure the flavor composition the observation of the long-elusive tau neutrinos is required. Starting at an energy of ~O(100 TeV) a tau neutrino charged current interaction can produce a double cascade topology, where the two energy depositions from the tau creation and the tau decay vertices are resolvable. This topology together with the well-established track and single cascade topology is used to measure the flavor composition on Earth. In this work, high-energy events starting in IceCube's detector volume are classified algorithmically into the three topologies. In the dataset with a livetime of 7.5 years, two events are classified as double cascades for the first time, yielding multi-TeV tau-neutrino candidates. The properties of the two tau-neutrino candidates are investigated in an a-posteriori analysis. The statistical method is improved by performing a log-likelihood-ratio test using multi-dimensional probability densities. One of the double cascades is consistent with being a misclassified single cascade, while the second double cascade is found to have a misclassification probability of only 3%. The measured flavor composition nu_e:nu_mu:nu_tau = 0.20:0.39:0.42 is consistent with astrophysical neutrinos and with previously published results. The astrophysical tau-neutrino flux is measured to dPhi / dE=3.0 (-1.8,+2.2) (E / 100TeV)^(-2.87) 10^(-18) GeV^(-1) cm^(-2) s^(-1) sr^(-1) with spectral index gamma=2.87 (-0.20,+0.21), yielding the first non-zero results for the tau normalization. The absence of an astrophysical tau-neutrino flux is disfavored at 2.8 sigma.

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Wren, Steven. "Neutrino mass ordering studies with IceCube-DeepCore." Thesis, University of Manchester, 2018. https://www.research.manchester.ac.uk/portal/en/theses/neutrino-mass-ordering-studies-with-icecubedeepcore(70414fde-3bef-4028-877b-5e1e86b2165d).html.

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The IceCube Neutrino Observatory at the South Pole is the world's largest neutrino detector with over 1km^3 of instrumented Antarctic ice. While it has been primarily designed to observe astrophysical neutrinos, this size also allows it to collect vast quantities of atmospheric neutrinos. These high-statistics datasets allow for measurements of the properties of neutrinos, in particular the phenomena of neutrino oscillation. One of the outstanding questions in this field is that of the neutrino mass ordering (NMO). The Precision IceCube Next Generation Upgrade (PINGU) is a proposed low-energy extension to IceCube for which a determination of the NMO is a priority science goal. The current low-energy atmospheric neutrino experiment at the South Pole, DeepCore, has been successfully collecting data since 2011. In this thesis the potential of this existing data to determine the NMO has been explored. While it was not expected to have a large sensitivity, this work has explored a Feldman-Cousins treatment for converting the delta-chi^2 between the two discrete mass ordering hypotheses into the standard Gaussian significance metric. Using 2.7 years of data from the DeepCore detector, the inverted mass ordering was preferred at the level of 0.05sigma. The second aspect of this thesis was to study the impact of the systematic uncertainties on the NMO determination. This particular analysis was actually statistics-limited and so the only impactful systematic uncertainties were the parameters that govern atmospheric neutrino oscillations, theta_23 and Deltam^2_31. Therefore, to improve the NMO results, these parameters were constrained by including the global information on them in the fits, yielding a new NMO sensitivity of 0.29sigma. This new global fit also yields measurements of the oscillation parameters of Deltam^2_32,NO=(2.443+/-0.037)e-3eV^2 and sin^2theta_23,NO=0.442+0.026-0.018 for the hypothesis of the normal mass ordering and Deltam^2_32,IO=(-2.510+/-0.036)e-3eV^2 and sin^2theta_23,IO=0.579+0.019-0.021 for the hypothesis of the inverted mass ordering. In addition to the work on the neutrino mass ordering, this thesis also investigated two issues related to predictions of the flux of atmospheric particles. The first related to the treatment of the predictions of the atmospheric neutrino flux, provided in binned tables. Crucially, these contain values representative of the integral of the flux across that bin and so an integral-preserving interpolation must be used. One such method will be presented along with a discussion of how it performs in the two-dimensional case of the atmospheric neutrino flux. The second issue related to quantifying uncertainties on the background muon distributions observed with the IceCube detector coming from the uncertainties on the initial cosmic ray flux. This involved performing a global fit on the available cosmic ray flux measurements and then propagating these uncertainties in to the muon distributions. To finalise this section, the exact manner in which these uncertainties can be included in the physics analyses of IceCube will be discussed.

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Stachurska, Juliana [Verfasser]. "Astrophysical Tau Neutrinos in IceCube / Juliana Stachurska." Berlin : Humboldt-Universität zu Berlin, 2020. http://d-nb.info/1216876991/34.

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Hickford, Stephanie Virginia. "Simulation of Cascades for the IceCube Neutrino Telescope." Thesis, University of Canterbury. Physics and Astronomy, 2007. http://hdl.handle.net/10092/1427.

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Neutrino telescopes open a new observational window on the universe. Neutrino interactions in these detectors can give rise to a combination of electromagnetic cascades, hadronic cascades and long range muons. Cerenkov radiation from these products is detected by the neutrino telescope. In this thesis the observational signatures associated with various neutrino-nucleon interaction products are investigated. Cerenkov radiation is emitted at a distinctive angle, about 40o in ice. The maximum number of optical photons that can be produced per unit charged tracklength is calculated to be 562 photons cm−1. The simulation programs Pythia and GEANT are used to study neutrino interactions using ice as the medium. The production of tau from the tau neutrino interaction is considered and it is found that the Cerenkov angle from tau is not distinctive at low energies, due to its lifetime tau decays before travelling an observable distance. The energy required for a tau neutrino to produce a sharp tau Cerenkov signal is on the order of 1 PeV. In a high energy electron neutrino interaction the resulting hadronic cascade contains high energy pions and kaons. These particles decay, often producing muons that are also high energy and therefore long range. Due to the muons travelling faster than the local speed of light in ice, their signal may be received by the detector earlier than the signal resulting from the event that created the muon. This can complicate the reconstruction of electron neutrino events.

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Hickford, Stephanie Virginia. "A Cascade Analysis for the IceCube Neutrino Telescope." Thesis, University of Canterbury. Physics and Astronomy, 2012. http://hdl.handle.net/10092/10014.

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IceCube is the largest operating neutrino observatory. An array of photomultiplier tubes deployed throughout a cubic kilometre of the Antarctic ice at the South Pole detect the Cherenkov radiation from neutrino-nucleon interactions. IceCube is capable of detecting neutrinos over a large energy range. The physics manifesto includes dark matter searches, cosmic ray observation, all sky point source searches, and particle physics parameter constraints. Astrophysical neutrinos are expected to originate from hadronic interactions in some of the most energetic regions in the Universe. The detection of high energy astrophysical neutrinos will provide direct information about the astrophysical sources that produced them. This thesis concentrates on the cascade channel for neutrino detection. Two separate studies are performed; a high energy cascade analysis and a parameterisation of the production of muons within hadronic cascades. The experimental data for the cascade analysis was taken by IceCube from April 2008 to May 2009 when the first 40 IceCube strings were deployed and operational. The analysis was designed to isolate the astrophysical neutrino signal from the atmospheric and muon background. Fourteen cascade-like events were observed, on a background of 2.2 ⁺⁰·⁶ ₋₀·₈ atmospheric neutrino events and 7.7 ± 1.0 atmospheric muon events. This gives a 90% confidence level upper limit of ΦlimE²≤ 7.46 × 10⁻⁸ GeVsr⁻¹s⁻¹cm⁻² , assuming an E⁻² spectrum and a neutrino flavour ratio of 1 : 1 : 1, for the energy range 25.12 TeV to 5011.87 TeV. Decay of hadronic particles in cascades produces muons. If the muons are energetic enough they can significantly alter the topology of the cascade and hence the reconstruction of the event in an analysis. The production of high energy muons within hadronic cascades was simulated and parameterised using Pythia and GEANT simulation programs.

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McCartin, Joseph William. "Cascade Reconstruction Analysis with the IceCube Neutrino Detector." Thesis, University of Canterbury. Physics and Astronomy, 2009. http://hdl.handle.net/10092/2609.

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A study into the reconstruction of cascade like events in the IceCube neutrino detector was performed by utilizing in-situ flasher devices. Reconstruction analysis was done with two different flasher settings at each optical module on string 63 at varying depths in the ice. Three different reconstruction algorithms were used to estimate the characteristics of these cascade type events. The characteristics included the estimated vertex position, and the number of photons produced by each flasher. The number of photons produced can be related to the energy for the cascade event via the detailed knowledge of the cascade physics. Results from the analysis show the strengths of using the center of gravity type approaches to estimating the vertex positions of very bright events, and the inability to reconstruct to an accurate position in z which can occur when using more complicated vertex algorithms on the same events. Analysis using the energy reconstruction modules demonstrated the strengths of using methods that take into account the ice properties inside the detector.

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10

Daughhetee, Jacob D. "Search for neutrino transients using IceCube and DeepCore." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53462.

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Observations indicate that there is a correlation between long duration gamma-ray bursts (GRBs) and core-collapse supernovae (SNe). The leading model for GRB production assumes that relativistic jets are generated by the core-collapse within the progenitor star. Charged particles undergo Fermi-acceleration within internal shocks of these jets and subsequently give rise to gamma ray emission once the jets breach the surrounding stellar envelope. Very few SNe result in the occurrence of GRBs, however, it has been suggested that a significant fraction of core-collapse SNe manage to produce mildly relativistic jets. These jets are insufficiently energetic to break through the envelope and are effectively ’choked’ resulting in a lack of observed gamma ray emission. In both the failed and successful GRB scenario, neutrino production can occur if protons are accelerated in the internal shocks of these jets. These neutrinos may be detectable by the IceCube neutrino observatory and its low energy extension DeepCore. This thesis presents the methods and results of a dedicated search for temporal and spatial clustering of neutrino events during the IceCube 2012 data season. Examination of 22,040 neutrino event candidates acquired over a detector livetime of 330 days revealed no statistically significant transient source of neutrino emission. Limits on the rate of choked GRBs in the nearby universe for possible values of neutrino emission model parameters are presented.

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Books on the topic "Icecore"

1

Whyman, Matt. Icecore: A Carl Hobbes thriller / Matt Whyman. New York: Atheneum Books for Young Readers, 2007.

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D, Clow G., and Geological Survey (U.S.), eds. Deconvolution of continuous borehole temperature logs: Example from the Greenland GISP2 icecore hole. [Reston, Va.]: Dept. of the Interior, U.S. Geological Survey, 1994.

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Breen, Jon L. The drowning icecube, and other stories. Unity, Me: Five Star, 1999.

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Hotel), International Conference on Electrical and Computer Engineering (5th 2008 Dhaka Sheraton. Proceedings of ICECE, 2008. Dhaka: ICECE 2008 Conference Secretariat, Dept. of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, 2008.

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International Conference on Electrical and Computer Engineering (5th 2008 Dhaka Sheraton Hotel). Proceedings of ICECE, 2008. Dhaka: ICECE 2008 Conference Secretariat, Dept. of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, 2008.

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Halzen, F. Icecube and the discovery of high-energy cosmic neutrinos. Firenze: Leo S. Olschki, 2018.

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International, Conference on Applied Electromagnetics and Communications (19th 2007 Dubrovnik Croatia). ICECom 2007: 19th International Conference on Applied Electromagnetics and Communications, 24-26 September 2007, Dubrovnik, Croatia. Zagreb, Croatia: KoREMA, 2007.

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International Conference on Applied Electromagnetics and Communications (19th 2007 Dubrovnik, Croatia). ICECom 2007: 19th International Conference on Applied Electromagnetics and Communications, 24-26 September 2007, Dubrovnik, Croatia. Edited by Bonefačić Davor. Zagreb, Croatia: KoREMA, 2007.

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International Conference on Applied Electromagnetics and Communications (19th 2007 Dubrovnik, Croatia). ICECom 2007: 19th International Conference on Applied Electromagnetics and Communications, 24-26 September 2007, Dubrovnik, Croatia. Edited by Bonefačić Davor. Zagreb, Croatia: KoREMA, 2007.

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International Conference on Applied Electromagnetics and Communications (19th 2007 Dubrovnik, Croatia). ICECom 2007: 19th International Conference on Applied Electromagnetics and Communications, 24-26 September 2007, Dubrovnik, Croatia. Edited by Bonefačić Davor. Zagreb, Croatia: KoREMA, 2007.

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Book chapters on the topic "Icecore"

1

Bast, Hannah, and Claudius Korzen. "The Icecite Research Paper Management System." In Lecture Notes in Computer Science, 396–409. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-41154-0_30.

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Sadhukhan, Soumya, Ashish Narang, and Subhendra Mohanty. "Icecube Spectrum: Neutrino Splitting and Neutrino Absorption." In Springer Proceedings in Physics, 987–93. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4408-2_143.

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Chauhan, Bhavesh, and Subhendra Mohanty. "Signature of Light Sterile Neutrinos at IceCube." In Springer Proceedings in Physics, 953–56. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4408-2_137.

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McLeod, Alexus. "Comet—A Sea ofDust Dust and IceComet Description." In Astronomy in the Ancient World, 109–25. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-23600-1_5.

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Hieronymus, Maicon, Bertil Schmidt, and Sebastian Böser. "Reconstruction of Low Energy Neutrino Events with GPUs at IceCube." In Lecture Notes in Computer Science, 118–31. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50371-0_9.

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Pandey, Madhurima, Debasish Majumdar, Ashadul Halder, and Shibaji Banerjee. "Mass and Life Time of Heavy Dark Matter Decay into IceCube PeV Neutrinos." In Springer Proceedings in Physics, 311–16. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-6292-1_38.

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Philipp, C., J. Shaltout, and H. P. Berlien. "Continuous Icecube Cooling of the Skin During Nd:YAG-Laser Treatment of Congenital Vascular Disorders (CVD)." In Laser in der Medizin / Laser in Medicine, 304–7. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-80264-5_76.

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Pandey, Sujata. "Can New Interactions with Dark Matter Lead to Flux Change of Astrophysical Neutrinos at Icecube?" In Springer Proceedings in Physics, 977–80. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4408-2_141.

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Blaufuss, Erik, and Albrecht Karle. "A Next-Generation IceCube: The IceCube-Gen2 Facility for High-Energy Neutrino Astronomy." In Neutrino Astronomy, 183–97. WORLD SCIENTIFIC, 2017. http://dx.doi.org/10.1142/9789814759410_0013.

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Strahler, E. "RECENT RESULTS FROM THE ICECUBE NEUTRINO TELESCOPE." In Particle Physics at the Tercentenary of Mikhail Lomonosov, 181–85. WORLD SCIENTIFIC, 2013. http://dx.doi.org/10.1142/9789814436830_0039.

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Conference papers on the topic "Icecore"

1

Halzen, Francis, Livius Trache, Alexei Smirnov, and Sabin Stoica. "IceCube." In EXOTIC NUCLEI AND NUCLEAR∕PARTICLE ASTROPHYSICS (III): From Nuclei to Stars. AIP, 2010. http://dx.doi.org/10.1063/1.3527210.

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Karle, Albrecht. "IceCube." In XV International Workshop on Neutrino Telescopes. Trieste, Italy: Sissa Medialab, 2014. http://dx.doi.org/10.22323/1.196.0053.

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Hultqvist, Klas. "IceCube results." In XVI International Workshop on Neutrino Telescopes. Trieste, Italy: Sissa Medialab, 2016. http://dx.doi.org/10.22323/1.244.0053.

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Spiering, Christian. "IceCube: Astrophysics Results." In XVII International Workshop on Neutrino Telescopes. Trieste, Italy: Sissa Medialab, 2018. http://dx.doi.org/10.22323/1.307.0083.

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"ICECOCS 2020 Committees." In 2020 IEEE 2nd International Conference on Electronics, Control, Optimization and Computer Science (ICECOCS). IEEE, 2020. http://dx.doi.org/10.1109/icecocs50124.2020.9314299.

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Williams, Dawn. "Results from IceCube." In 36th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2019. http://dx.doi.org/10.22323/1.358.0016.

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Ahlers, Markus, and Francis Halzen. "Highlights from IceCube." In International School of Subnuclear Physics, ISSP 2016, 54th Course. WORLD SCIENTIFIC, 2019. http://dx.doi.org/10.1142/9789811206856_0014.

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Schulz, Olaf, Felix A. Aharonian, Werner Hofmann, and Frank Rieger. "The IceCube DeepCore." In HIGH ENERGY GAMMA-RAY ASTRONOMY: Proceedings of the 4th International Meeting on High Energy Gamma-Ray Astronomy. AIP, 2008. http://dx.doi.org/10.1063/1.3076796.

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Martin, Richard A., Tim Thompson, Naseem Ansari, and Chokri Guetari. "IceCube CFD Drilling Model." In ASME 2006 2nd Joint U.S.-European Fluids Engineering Summer Meeting Collocated With the 14th International Conference on Nuclear Engineering. ASMEDC, 2006. http://dx.doi.org/10.1115/fedsm2006-98042.

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A numerical model of a hot water drill used to produce deep holes in clear ice at the South Pole for the IceCube neutrino observatory program scheduled for completion in 2010 has been developed. The model was built using the ANSYS commercial computational fluid dynamics (CFD) code, ANSYS CFX. This drill model is helping us to understand the water/ice melting process near the bottom of the drill hole, and to evaluate the influence of nozzle size, spray angle, water flow rate, and water temperature on the drill hole shape, and on drilling speed. The basis for the model is ANSYS CFX, which has multi-phase, conjugate heat transfer capabilities. The model utilizes a multi-phase approach, and simulates motion of the drill with respect to the ice. The sensitivity of model predictions to mesh resolution, turbulence model, and interfacial heat transfer coefficients, area, and drag coefficient was studied, and the results were used to determine preferred values in each case. This multi-phase model was selected after evaluating an equilibrium model and obtaining results showing not completely satisfactory comparisons to experimental data from the South Pole. Computations at a drill depth of 1292 m allowed validation of code results using actual field data obtained during the 2004–2005 IceCube drilling season at Antarctica. A series of steady-state runs using two drill sizes, two drill speeds, and one spray angle were performed for conditions at 1292 m to determine if a smaller nozzle orifice would enable faster drilling, preferably by a factor of two. The model predicted a drill hole diameter of from 18 in to 25 in and an up-flow water temperature of from 20°C to 28°C. The drill hole diameter is consistent with values measured at the IceCube site, but the water temperature is about 10°C low. No evidence of the nozzle tip impacting the bottom of the hole was found in the drill speed range 3.5 ft/min to 7 ft/min. A nozzle spray angle of 25 degrees was found to make little difference in hole depth or diameter. Reducing the nozzle diameter from 1 in to 0.75 in at the same water volumetric flow rate resulted in an increase in the drill hole depth by from 16% to 20%. The latter result implies that faster drilling is expected when using a smaller size orifice with zero degree spray angle. The IceCube drill model is now available to determine the effects of key variables, to evaluate the performance of new nozzle designs, and to specify drill speed versus depth. Recommendations specific to faster drilling speeds resulted in a near doubling of actual speed during the 2005–2006 season at the South Pole.

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Matin, Kaiser, Avram Bar-Cohen, and Joseph J. Maurer. "Modeling and Simulation Challenges in Embedded Two Phase Cooling: DARPA’s ICECool Program." In ASME 2015 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems collocated with the ASME 2015 13th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ipack2015-48334.

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Modeling and simulation of two-phase phenomena, as well as their impact on electrical performance and physical integrity are critical to the success of embedded cooling strategies. In DARPA’s Intrachip/Interchip Embedded Cooling (ICECool) program, thermal/electrical/mechanical co-simulation and modeling tools are being applied to the analysis and design of RF GaN MMIC (Monolithic Microwave Integrated Circuit) Power Amplifiers (PA) and digital ICs, with the ultimate goal of achieving greater than 3X electronic performance improvement. This paper addresses various simulation strategies and numerical techniques adopted by the DARPA ICECool performers, with attention devoted to co-simulation through coupled iterations of thermal, mechanical and electrical behavior for capturing device characteristics and predicting reliability and “best in class” simulations that can provide an understanding of device behavior during rugged operating conditions impacted by multi-physics environments. The effect of CTE (Coefficient of Thermal Expansion) mismatch on bond and structural integrity, the impact of cooling fluid choice on performance, the factors affecting erosion/corrosion in the microchannels, as well as electro-migration limits and joule heating effects, will also be addressed. A separate discussion of various two-phase issues, including interface tracking, system pressure drops, conjugate heat transfer, estimating near wall heat transfer coefficients, and predicting CHF (Critical Heat Flux) and dryout is also provided.

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Reports on the topic "Icecore"

1

Laha, Ranjan, and Stanley J. Brodsky. IC at IC: IceCube can constrain the intrinsic charm of the proton. Office of Scientific and Technical Information (OSTI), August 2016. http://dx.doi.org/10.2172/1293666.

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