A5058353105- Mathematical Dynamics and Fractals
- Cryospheric studies and observations
- Winter Sports Injuries and Performance
- Landslides and related hazards
- Graphite, nuclear technology, radiation studies
- Nuclear Physics and Applications
- Radiation Effects in Electronics
- Nuclear reactor physics and engineering
- Arctic and Antarctic ice dynamics
- Radiation Therapy and Dosimetry
- Radiation Detection and Scintillator Technologies
- Chaos control and synchronization
- Advanced Semiconductor Detectors and Materials
- Astronomy and Astrophysical Research
- Advanced Topology and Set Theory
- Quantum chaos and dynamical systems
- Theoretical and Computational Physics
- Astronomical Observations and Instrumentation
- Radiation Shielding Materials Analysis
- Methane Hydrates and Related Phenomena
- Stellar, planetary, and galactic studies
- Marine and coastal ecosystems
- Geology and Paleoclimatology Research
- Water Quality Monitoring and Analysis
- Electron and X-Ray Spectroscopy Techniques
Plymouth Marine Laboratory
2020-2024
University of Bristol
2013-2022
Stanford University
2018-2022
National Energy Technology Laboratory
2018
Royal Surrey County Hospital
2018
W. M. Keck Foundation
2016
University of Southern California
2016
University of Georgia
2011-2015
MEI Technologies (United States)
2014
Seabrook
2014
Abstract Greenland's bed topography is a primary control on ice flow, grounding line migration, calving dynamics, and subglacial drainage. Moreover, fjord bathymetry regulates the penetration of warm Atlantic water (AW) that rapidly melts undercuts marine‐terminating glaciers. Here we present new compilation Greenland assimilates seafloor thickness data through mass conservation approach. A 150 m horizontal resolution topography/bathymetric map constructed with seamless transitions at...
Abstract The development of algorithms for remote sensing water quality (RSWQ) requires a large amount in situ data to account the bio-geo-optical diversity inland and coastal waters. GLObal Reflectance community dataset Imaging optical Aquatic environments (GLORIA) includes 7,572 curated hyperspectral reflectance measurements at 1 nm intervals within 350 900 wavelength range. In addition, least one co-located measurement chlorophyll , total suspended solids, absorption by dissolved...
Abstract Curie depths beneath Greenland are revealed by spectral analysis of data from the World Digital Magnetic Anomaly Map 2. A thermal model lithosphere then provides a corresponding geothermal heat flux map. This new map exhibits significantly higher frequency but lower amplitude variation than earlier maps and an important boundary condition for numerical ice‐sheet models interpretation borehole temperature profiles. In addition, it reveals geologically significant features. Notably,...
The proton-induced nonionizing energy loss (NIEL) for representative device materials are presented the range between displacement damage threshold to 1 GeV. All interaction mechanisms (Coulomb and nuclear elastic/nonelastic) fully accounted in present NIEL calculations. For Coulomb interactions, Ziegler-Biersack-Littmark (ZBL) screened potential was used lower (<50 MeV) relativistic formulation higher (/spl ges/50 MeV). A charged particle transport code, MCNPX, compute due interactions.
Abstract. Subglacial roughness can be determined at a variety of length scales from radio-echo sounding (RES) data either via statistical analysis topography or inferred basal radar scattering. Past studies have demonstrated that subglacial terrain exhibits self-affine (power law) scaling behaviour, but existing scattering models do not take this into account. Here, using RES northern Greenland, we introduce framework enables consistent integration topographic-scale with the electromagnetic...
Ice crystal orientation fabric (COF) records information about past ice-sheet deformation and influences the present-day flow of ice. Polarimetric radar sounding provides a means to infer anisotropic COF patterns due associated birefringence polar Here, we develop polarimetric coherence (phase-based) method determine horizontal properties COF. The utilizes azimuth depth dependence vertical gradient hhvv phase dielectric principal axes birefringence, which are then related second-order...
Abstract Here we use polarimetric measurements from an Autonomous phase-sensitive Radio-Echo Sounder (ApRES) to investigate ice fabric within Whillans Ice Stream, West Antarctica. The survey traverse is bounded at one end by the suture zone with Mercer Stream and other a basal ‘sticky spot’. Our data analysis employs phase-based coherence method estimate horizontal properties: orientation magnitude of asymmetry. We infer azimuthal rotation in prevailing c -axis between near-surface ( z ≈...
The Amundsen Sea Embayment of the West Antarctic Ice Sheet contains Thwaites and Pine Island Glaciers, two most rapidly changing glaciers in Antarctica. To date, Glaciers have only been observed by independent airborne radar sounding surveys, but a combined cross-basin analysis that investigates basal conditions across Island-Thwaites boundary has not performed. Here, we combine surveys correct for their differences system parameters to produce unified englacial attenuation relative...
We describe an analytical model for calculating nonionizing energy loss (NIEL) heavy ions based on screened Coulomb potentials in the nonrelativistic limit. The applies to any incident ion target material where interaction is primarily responsible atomic displacement. Results are compared with previous methods of extracting NIEL from Monte Carlo SRIM runs. Examples calculations given having energies ranging threshold displacement 1 GeV. include H, He, B, Si, Fe, Xe, and Au. Example targets...
Background β-Alanine (βA) has been shown to improve performance during cycling. This study was the first examine effects of βA supplementation on onset blood lactate accumulation (OBLA) incremental treadmill running.Methods Seventeen recreationally-active men (mean ± SE 24.9 4.7 yrs, 180.6 8.9 cm, 79.25 9.0 kg) participated in this randomized, double-blind, placebo-controlled pre/post test 2-treatment experimental design. Subjects two tests before and after 28 days with either (6.0...
We describe the bi-directed eyes of a mesopelagic teleost fish, Rhynchohyalus natalensis, that possesses an extensive lateral diverticulum to each tubular eye. Each contains mirror focuses light from ventro-lateral visual field. This species can thereby visualize both downwelling sunlight and bioluminescence over wide field view. Modelling shows is very likely be capable producing bright, well focused image. After Dolichopteryx longipes, this only second description eye in vertebrate having...
Abstract. There is widespread, but often indirect, evidence that a significant fraction of the bed beneath Greenland Ice Sheet thawed (at or above pressure melting point for ice). This includes beds major outlet glaciers and their tributaries large area around NorthGRIP borehole in ice-sheet interior. The ice-sheet-scale distribution basal water is, however, poorly constrained by existing observations. In principle, airborne radio-echo sounding (RES) enables detection from bed-echo...
Abstract We use polarimetric radar sounding to investigate ice crystal orientation fabric and its impact on viscosity within the near surface of Rutford Ice Stream, West Antarctica. The technique retrieves lateral depth variations in horizontal components but no direct information vertical component. In shallowest (depths 40–100 m), is consistent with flow‐induced development correlates compression direction. Notably, toward ice‐stream margin, angle azimuthal tend 45° relative flow which...
Abstract. In situ measurements of particulate inherent optical properties (IOPs) – absorption (ap(λ)), scattering (bp(λ)), and beam attenuation (cp(λ)) are crucial for the development algorithms that retrieve biogeochemical quantities such as chlorophyll a, organic carbon (POC), total suspended matter (TSM). Here we present a compilation absorption–attenuation spectrophotometric data measured underway on nine Atlantic Meridional Transect (AMT) cruises between 50° N S from 2009–2019. The...
A probabilistic model of cumulative solar heavy ion energy and LET spectra is developed for spacecraft design applications. Spectra are given as a function confidence level, mission time period during maximum shielding thickness. It shown that long-term fluxes exceed galactic cosmic ray levels interest. Cumulative fluences should therefore be accounted in single event effects rate calculations the planning space missions.
Abstract. The subglacial environment of the Greenland Ice Sheet (GrIS) is poorly constrained both in its bulk properties, for example geology, presence sediment, and water, interfacial conditions, such as roughness bed rheology. There is, therefore, limited understanding how spatially heterogeneous properties relate to ice-sheet motion. Here, via analysis 2 decades radio-echo sounding data, we present a new systematic beneath GrIS. We use two independent methods quantify roughness: first,...
In this paper we prove a multifractal formalism of Birkhoff averages for interval maps with countably many branches. Furthermore, that under certain regularity assumptions on the potential spectrum is real analytic. Applications these results to number theory are also given. Finally, compute Hausdorff dimension set points which average infinite.
Many animals use structural coloration to create bright and conspicuous visual signals. Selection of the size shape optical structures defines both colour intensity light reflected. The material used these reflectors is also important; however, are restricted a limited number materials: commonly chitin, guanine protein, reflectin. In this work we highlight that particular set properties can be under selection in order increase functionality reflectors. Specifically, polarization properties,...
Multilayer optical reflectors constructed from ‘stacks’ of alternating layers high and low refractive index dielectric materials are present in many animals. For example, stacks guanine crystals with cytoplasm gaps occur within the skin scales fish, protein platelets iridophores cephalopods. Common to all these animal multilayer different degrees random variation thicknesses individual stack, ranging highly periodic structures strongly disordered systems. However, previous discussions...
Abstract Radar‐sounding surveys measuring ice thickness in Greenland have enabled an increasingly “complete” knowledge of basal topography and glaciological processes. Where such observations are spatially limited, bed elevation has been interpolated through mass conservation or kriging. Ordinary kriging fails to resolve anisotropy geometry, however, leaving complex misrepresented models the sheet bed. Here, we demonstrate potential new high‐resolution (≤5 m) surface data (ArcticDEM) provide...
Abstract In airborne radargrams, undulating periodic patterns in amplitude that overprint traditional radiostratigraphic layering are occasionally observed, however, they have yet to be analyzed from a geophysical or glaciological perspective. We present evidence supported by theory these depth‐periodic consistent with modulation of the received radar power due birefringence polar ice, and therefore indicate presence bulk fabric anisotropy. Here, we investigate component...