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Real-Time Monitoring Of Uncertainty Due To Refraction In Multibeam Echo Sounding, Jonathan Beaudoin Oct 2010

Real-Time Monitoring Of Uncertainty Due To Refraction In Multibeam Echo Sounding, Jonathan Beaudoin

Center for Coastal and Ocean Mapping

A software toolkit has been developed to objectively monitor uncertainty due to refraction in multibeam echosounding, specifically mapping systems that employ underway sound speed profiling hardware. The toolkit relies on the use of a raytrace simulator which mimics the sounding geometry of any given echosounder, specifically array type, angular sector, draft, and availability of a surface sound speed probe. The simulator works by objectively comparing a pair of consecutively collected sound speed profiles and reporting sounding uncertainty across the entire potential sounding space. Realtime visualizations of the uncertainty as a function of time and space allow the operator to tune …


World's Rivers In State Of Crisis, Nature Report Details, David Sims Sep 2010

World's Rivers In State Of Crisis, Nature Report Details, David Sims

Media Relations

No abstract provided.


Evolving Outer Heliosphere: Large-Scale Stability And Time Variations Observed By The Interstellar Boundary Explorer, D. J. Mccomas, M. Bzowski, P. Frisch, G. B. Crew, M. A. Dayeh, R. Demajistre, H. O. Funsten, S. A. Fuselier, M. Gruntman, P. Janzen, M. A. Kubiak, G Livadiotis, Eberhard Moebius, D. B. Reisenfeld, Nathan A. Schwadron Sep 2010

Evolving Outer Heliosphere: Large-Scale Stability And Time Variations Observed By The Interstellar Boundary Explorer, D. J. Mccomas, M. Bzowski, P. Frisch, G. B. Crew, M. A. Dayeh, R. Demajistre, H. O. Funsten, S. A. Fuselier, M. Gruntman, P. Janzen, M. A. Kubiak, G Livadiotis, Eberhard Moebius, D. B. Reisenfeld, Nathan A. Schwadron

Physics & Astronomy

The first all-sky maps of Energetic Neutral Atoms (ENAs) from the Interstellar Boundary Explorer (IBEX) exhibited smoothly varying, globally distributed flux and a narrow "ribbon" of enhanced ENA emissions. In this study we compare the second set of sky maps to the first in order to assess the possibility of temporal changes over the 6 months between views of each portion of the sky. While the large-scale structure is generally stable between the two sets of maps, there are some remarkable changes that show that the heliosphere is also evolving over this short timescale. In particular, we find that (1) …


Conserving The Pawtuckaway River Focus Area And Kennard Hill Focus Area : Final Report, Brian Hart Sep 2010

Conserving The Pawtuckaway River Focus Area And Kennard Hill Focus Area : Final Report, Brian Hart

PREP Reports & Publications

The Piscataqua Region Estuaries Partnership provided $8,000 to support the Southeast Land Trust of New Hampshire’s land conservation work within the Pawtuckaway River and Kennard Hill Focus Areas, two areas identified by the Land Conservation Plan for New Hampshire’s Coastal Watershed. Through this grant, the Southeast Land Trust has: permanently conserved two parcels totaling 90.55 acres within the Pawtuckaway River Focus Area; entered into four agreements to acquire and conserve 221.4 acres within the Pawtuckaway River Focus Area and 190 acres within the Kennard Hill Focus Area; and facilitated, through the Wetlands Reserve Program, the protection of 60 acres within …


2010-11 Faculty Senate - September 27, 2010 Minutes Summary, Faculty Senate Sep 2010

2010-11 Faculty Senate - September 27, 2010 Minutes Summary, Faculty Senate

Faculty Senate Agendas & Minutes

No abstract provided.


Eelgrass Distribution In The Great Bay Estuary For 2009 : Final Report, Frederick T. Short Sep 2010

Eelgrass Distribution In The Great Bay Estuary For 2009 : Final Report, Frederick T. Short

PREP Reports & Publications

Eelgrass in the Great Bay Estuary in 2009 was once again present only in Great Bay itself and in Portsmouth Harbor. For the second year in a row, there was no eelgrass in Little Bay or in the Piscataqua River. In 2009, there was a continued loss of eelgrass biomass in Great Bay; there has been a 66.4% loss of biomass in Great Bay since 1996 and distribution is 30% less than in 1996. Although eelgrass distribution in Great Bay itself increased between 2008 and 2009, primarily due to continued expansion from natural seeding of bare areas, the Bay’s eelgrass …


Results Of The Gulfwatch 2010 Samples : Memorandum, Matthew A. Wood Sep 2010

Results Of The Gulfwatch 2010 Samples : Memorandum, Matthew A. Wood

PREP Reports & Publications

The purpose of this memorandum is to document the sample collection activities for Gulfwatch 2010. .


Unh Sidore Series Focuses On The Past, Present And Future Of The Ocean, Lori Wright Sep 2010

Unh Sidore Series Focuses On The Past, Present And Future Of The Ocean, Lori Wright

Media Relations

No abstract provided.


Unh Receives $1m+ To Prepare Math, Science Teachers For High-Need Schools, Beth Potier Sep 2010

Unh Receives $1m+ To Prepare Math, Science Teachers For High-Need Schools, Beth Potier

Media Relations

No abstract provided.


A Portable Neutron Spectroscope (Nspect) For Detection, Imaging And Identification Of Nuclear Material, James M. Ryan, Chris Bancroft, Peter F. Bloser, U Bravar, Dominique Fourguette, Colin Frost, Liane Larocque, Mark L. Mcconnell, Jason S. Legere, Jane Pavlich, Greg Ritter, Greg Wassick, Joshua Wood, R S. Woolf Sep 2010

A Portable Neutron Spectroscope (Nspect) For Detection, Imaging And Identification Of Nuclear Material, James M. Ryan, Chris Bancroft, Peter F. Bloser, U Bravar, Dominique Fourguette, Colin Frost, Liane Larocque, Mark L. Mcconnell, Jason S. Legere, Jane Pavlich, Greg Ritter, Greg Wassick, Joshua Wood, R S. Woolf

Space Science Center

We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the …


Studies Of Insulating Superconductors, Shawna M. Hollen, J C. Joy, Maura Lynch, H Q. Nguyen, M D. Stewart Jr, J Shainline, Aijun Yin, J M. Xu, J M. Valles Jr. Sep 2010

Studies Of Insulating Superconductors, Shawna M. Hollen, J C. Joy, Maura Lynch, H Q. Nguyen, M D. Stewart Jr, J Shainline, Aijun Yin, J M. Xu, J M. Valles Jr.

Physics & Astronomy

No abstract provided.


High Resolution Calibration Of A Multibeam Echo Sounder, Carlo Lanzoni, Thomas C. Weber Sep 2010

High Resolution Calibration Of A Multibeam Echo Sounder, Carlo Lanzoni, Thomas C. Weber

Center for Coastal and Ocean Mapping

Calibration can greatly increase the utility of collecting seafloor backscattering strength with multibeam echo sounders (MBES). A calibration procedure to determine high resolution, three dimensional transmit and receive beam patterns of a Reson SeaBat 7125 MBES was performed using the fresh water calibration tank at the University of New Hampshire. The measurements employed an omni-directional Reson TC4034 projector/hydrophone as a reference transducer at an acoustic distance of 13 m. The multibeam sonar system was configured for 256 beams equi-angle mode and operating frequency of 396 kHz. The transmit beam pattern was computed for across-track angular range between +/–90o in 0.1o …


Simulations Of A Monolithic Lanthanum Bromide Gamma-Ray Detector, Camden Ertley, Chris Bancroft, Peter F. Bloser, Taylor Connor, Jason S. Legere, Mark L. Mcconnell, James M. Ryan Aug 2010

Simulations Of A Monolithic Lanthanum Bromide Gamma-Ray Detector, Camden Ertley, Chris Bancroft, Peter F. Bloser, Taylor Connor, Jason S. Legere, Mark L. Mcconnell, James M. Ryan

Space Science Center

We have been working on the development of a detector design for a large area coded aperture imaging system operating in the 10-600 keV energy range. The detector design is based on an array of Lanthanum Bromide (LaBr3) scintillators, each directly coupled to a Hamamatsu 64-channel multi-anode photomultiplier tube (MAPMT). This paper focuses on the development of the GEANT4-based simulations as an aid in the optimization of the detector design. The simulations have been validated by comparisons with various laboratory data sets. We will summarize the current status and latest findings from this study.


The Production And Persistence Of Σrono2 In The Mexico City Plume, A E. Perring, T H. Bertram, D K. Farmer, Paul J. Wooldridge, Jack E. Dibb, N J. Blake, D R. Blake, H B. Singh, H Fuelberg, Glenn Diskin, G W. Sachse, Robert C. Cohen Aug 2010

The Production And Persistence Of Σrono2 In The Mexico City Plume, A E. Perring, T H. Bertram, D K. Farmer, Paul J. Wooldridge, Jack E. Dibb, N J. Blake, D R. Blake, H B. Singh, H Fuelberg, Glenn Diskin, G W. Sachse, Robert C. Cohen

Earth Sciences

Alkyl and multifunctional nitrates (RONO2, ΣANs) have been observed to be a significant fraction of NOy in a number of different chemical regimes. Their formation is an important free radical chain termination step ending production of ozone and possibly affecting formation of secondary organic aerosol. ΣANs also represent a potentially large, unmeasured contribution to OH reactivity and are a major pathway for the removal of nitrogen oxides from the atmosphere. Numerous studies have investigated the role of nitrate formation from biogenic compounds and in the remote atmosphere. Less attention has been paid to the role ΣANs may …


Unh Tech Camp Provides Hands-On Science For Secondary Students, David Sims Aug 2010

Unh Tech Camp Provides Hands-On Science For Secondary Students, David Sims

Media Relations

No abstract provided.


High Schoolers Launch Unique Balloon Experiment During Unh Summer Institute, David Sims Aug 2010

High Schoolers Launch Unique Balloon Experiment During Unh Summer Institute, David Sims

Media Relations

No abstract provided.


Meta-Analysis Of Fertilization Experiments Indicates Multiple Limiting Nutrients In Northeastern Deciduous Forests, Matthew A. Vadeboncoeur Aug 2010

Meta-Analysis Of Fertilization Experiments Indicates Multiple Limiting Nutrients In Northeastern Deciduous Forests, Matthew A. Vadeboncoeur

All Materials

It is widely accepted that nitrogen limits primary production in temperate forests, although co-limitation by N and P has also been suggested, and on some soils Ca and base cations are in short supply. I conducted a meta-analysis to assess the strength of existing experimental evidence for limitation of primary production by N, P, and Ca in hardwood forests of the northeastern United States and southeastern Canada, using data from 35 fertilization experiments in deciduous forests on glaciated soils across the region.

There is strong evidence for N limitation (formal meta-analysis weighted mean response ratio = 1.51, p < 0.01; simple mean = 1.42, p < 0.001). Forest productivity also tends to increase with additions of P (simple mean = 1.15, p = 0.05) and Ca (simple mean = 1.36 p < 0.001). Across all treatments, 85% of response ratios were positive. Multiple-element additions had larger effects than single elements, but factorial experiments showed little evidence of synergistic effects between nutrient additions. Production responses correlated positively with the rate of N fertilization, but this effect was reduced at high rates of ambient N deposition.


Plans For The First Balloon Flight Of The Gamma-Ray Polarimeter Experiment (Grape), Taylor Connor, Chris Bancroft, Peter F. Bloser, Jason S. Legere, Mark L. Mcconnell, James M. Ryan Jul 2010

Plans For The First Balloon Flight Of The Gamma-Ray Polarimeter Experiment (Grape), Taylor Connor, Chris Bancroft, Peter F. Bloser, Jason S. Legere, Mark L. Mcconnell, James M. Ryan

Space Science Center

We have developed a design for a hard X-ray polarimeter operating in the energy range from 50 to 500 keV. This modular design, known as GRAPE (Gamma-Ray Polarimeter Experiment), has been successfully demonstrated in the lab using partially polarized gamma-ray sources and using fully polarized photon beams at Argonne National Laboratory. In June of 2007, a GRAPE engineering model, consisting of a single detector module, was flown on a high altitude balloon flight to further demonstrate the design and to collect background data. We are currently preparing a much larger balloon payload for a flight in the fall of 2011. …


Development Of The Advance Energetic Pair Telescope (Adept) For Medium-Energy Gamma-Ray Astronomy, Stanley D. Hunter, Peter F. Bloser, Michael P. Dion, Mark L. Mcconnell, Georgia A. Denolfo, Seunghee Son, James M. Ryan, Floyd Stecker Jul 2010

Development Of The Advance Energetic Pair Telescope (Adept) For Medium-Energy Gamma-Ray Astronomy, Stanley D. Hunter, Peter F. Bloser, Michael P. Dion, Mark L. Mcconnell, Georgia A. Denolfo, Seunghee Son, James M. Ryan, Floyd Stecker

Space Science Center

Progress in high-energy gamma-ray science has been dramatic since the launch of INTEGRAL, AGILE and FERMI. These instruments, however, are not optimized for observations in the medium-energy (~0.3< Eγ < ~200 MeV) regime where many astrophysical objects exhibit unique, transitory behavior, such as spectral breaks, bursts, and flares. We outline some of the major science goals of a medium-energy mission. These science goals are best achieved with a combination of two telescopes, a Compton telescope and a pair telescope, optimized to provide significant improvements in angular resolution and sensitivity. In this paper we describe the design of the Advanced Energetic Pair Telescope (AdEPT) based on the Three-Dimensional Track Imager (3-DTI) detector. This technology achieves excellent, mediumenergy sensitivity, angular resolution near the kinematic limit, and gamma-ray polarization sensitivity, by high resolution 3-D electron tracking. We describe the performance of a 30×30×30 cm3 prototype of the AdEPT instrument.


A Fast Scintillator Compton Telescope For Medium-Energy Gamma-Ray Astronomy, Peter F. Bloser, James M. Ryan, Jason S. Legere, Manuel Julien, Chris Bancroft, Mark L. Mcconnell, Mark Wallace, R M. Kippen, Shawn Tornga Jul 2010

A Fast Scintillator Compton Telescope For Medium-Energy Gamma-Ray Astronomy, Peter F. Bloser, James M. Ryan, Jason S. Legere, Manuel Julien, Chris Bancroft, Mark L. Mcconnell, Mark Wallace, R M. Kippen, Shawn Tornga

Space Science Center

The field of medium-energy gamma-ray astronomy urgently needs a new mission to build on the success of the COMPTEL instrument on the Compton Gamma Ray Observatory. This mission must achieve sensitivity significantly greater than that of COMPTEL in order to advance the science of relativistic particle accelerators, nuclear astrophysics, and diffuse backgrounds, and bridge the gap between current and future hard X-ray missions and the high-energy Fermi mission. Such an increase in sensitivity can only come about via a dramatic decrease in the instrumental background. We are currently developing a concept for a low-background Compton telescope that employs modern scintillator …


Synthesis Of Satellite (Modis), Aircraft (Icartt), And Surface (Improve, Epa-Aqs, Aeronet) Aerosol Observations Over Eastern North America To Improve Modis Aerosol Retrievals And Constrain Surface Aerosol Concentrations And Sources, Easan Drury, Daniel J. Jacob, Robert J.D. Spurr, Jun Wang, Yohei Shinozuka, Bruce E. Anderson, A D. Clarke, Jack E. Dibb, Cameron Mcnaughton, Rodney J. Weber Jul 2010

Synthesis Of Satellite (Modis), Aircraft (Icartt), And Surface (Improve, Epa-Aqs, Aeronet) Aerosol Observations Over Eastern North America To Improve Modis Aerosol Retrievals And Constrain Surface Aerosol Concentrations And Sources, Easan Drury, Daniel J. Jacob, Robert J.D. Spurr, Jun Wang, Yohei Shinozuka, Bruce E. Anderson, A D. Clarke, Jack E. Dibb, Cameron Mcnaughton, Rodney J. Weber

Earth Sciences

We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations (PM2.5) from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and …


A Comparison Of Gc-Fid And Ptr-Ms Toluene Measurements In Ambient Air Under Conditions Of Enhanced Monoterpene Loading, Jesse L. Ambrose, K. Haase, R. S. Russo, Y. Zhou, M. L. White, E. K. Frinak, C. Jordan, Howard R. Mayne, Robert W. Talbot, B. C. Sive Jul 2010

A Comparison Of Gc-Fid And Ptr-Ms Toluene Measurements In Ambient Air Under Conditions Of Enhanced Monoterpene Loading, Jesse L. Ambrose, K. Haase, R. S. Russo, Y. Zhou, M. L. White, E. K. Frinak, C. Jordan, Howard R. Mayne, Robert W. Talbot, B. C. Sive

Chemistry

Toluene was measured using both a gas chromatographic system (GC), with a flame ionization detector (FID), and a proton transfer reaction-mass spectrometer (PTR-MS) at the AIRMAP atmospheric monitoring station Thompson Farm (THF) in rural Durham, NH during the summer of 2004. Simultaneous measurements of monoterpenes, including alpha- and beta-pinene, camphene, Delta(3)-carene, and d-limonene, by GC-FID demonstrated large enhancements in monoterpene mixing ratios relative to toluene, with median and maximum enhancement ratios of similar to 2 and similar to 30, respectively. A detailed comparison between the GC-FID and PTR-MS toluene measurements was conducted to test the specificity of PTR-MS for atmospheric …


Unh Eelgrass (Zostera Marina) Monitoring Program For 2010-2014: Quality Assurance Project Plan, Frederick T. Short, Phil Trowbridge Jul 2010

Unh Eelgrass (Zostera Marina) Monitoring Program For 2010-2014: Quality Assurance Project Plan, Frederick T. Short, Phil Trowbridge

PREP Reports & Publications

Eelgrass (Zostera marina) is essential to estuarine ecology because it filters nutrients and suspended particles from water, stabilizes sediments, provides food for wintering waterfowl, and provides habitat for juvenile fish and shellfish, as well as being the basis of an important estuarine food web. Healthy eelgrass both depends on and contributes to good water quality. The UNH Seagrass Ecology Lab, has mapped the distribution of eelgrass every year from 1986 through 2009 in the Great Bay. The entire Great Bay Estuary (Great Bay, Little Bay, tidal tributaries, Piscataqua River, Little Harbor, and Portsmouth Harbor) was mapped by these researchers in …


Do Scientists Agree About Climate Change? Public Perceptions From A New Hampshire Survey, Lawrence C. Hamilton Jul 2010

Do Scientists Agree About Climate Change? Public Perceptions From A New Hampshire Survey, Lawrence C. Hamilton

Carsey Publications

This report, a collaboration of the Carsey Institute, the UNH Survey Center, and the UNH Office of Sustainability, is the first of a new initiative that will track public perceptions about climate change as they change over time. Questions related to climate change were asked as part of New Hampshire's Granite State Poll, which surveyed 512 New Hampshire residents in April 2010.


Geodatabase Development To Support Hyperspectral Imagery Exploitation, Robert A. Fusina, John C. Fry, C Reid Nichols, Charles M. Bachmann, Rong-Rong Li, Jon Sellars, Christopher Parrish, Marcos J. Montes, Carl Gross, Stephen A. White, Krista Lee, Christopher A. Jones Jul 2010

Geodatabase Development To Support Hyperspectral Imagery Exploitation, Robert A. Fusina, John C. Fry, C Reid Nichols, Charles M. Bachmann, Rong-Rong Li, Jon Sellars, Christopher Parrish, Marcos J. Montes, Carl Gross, Stephen A. White, Krista Lee, Christopher A. Jones

Center for Coastal and Ocean Mapping

Geodatabase development for coastal studies conducted by the Naval Research Laboratory (NRL) is essential to support the exploitation of hyperspectral imagery (HSI). NRL has found that the remote sensing and mapping science community benefits from coastal classifications that group coastal types based on similar features. Selected features in project geodatabases relate to significant biological and physical forces that shape the coast. The project geodatabases help researchers understand factors that are necessary for imagery post processing, especially those features having a high degree of temporal and spatial variability. NRL project geodatabases include a hierarchy of environmental factors that extend from shallow …


Is New Hampshire's Climate Warming?, Lawrence C. Hamilton, Barry D. Keim, Cameron P. Wake Jul 2010

Is New Hampshire's Climate Warming?, Lawrence C. Hamilton, Barry D. Keim, Cameron P. Wake

Carsey Publications

This Carsey brief looks at temperature anomalies across New Hampshire and shows that not only is the state warmer than it has been in the past, but it is also warming faster than much of the planet. Sociologist Lawrence Hamilton, research associate professor Cameron Wake, and former NH state climatologist Barry Keim analyzed over 100 years of temperatures across the state to produce this data for the Carsey Institute in August 2010.


U.S. Law Of The Sea Cruise To Map The Southern Flank Of The Kingman Reef-Palmyra Atoll Section Of The Line Islands, Equatorial Pacific Ocean, James V. Gardner, Brian R. Calder Jun 2010

U.S. Law Of The Sea Cruise To Map The Southern Flank Of The Kingman Reef-Palmyra Atoll Section Of The Line Islands, Equatorial Pacific Ocean, James V. Gardner, Brian R. Calder

Center for Coastal and Ocean Mapping

U.S. Law of the Sea Cruise to Map the Southern Flank of the Kingman Reef-Palmyra Atoll section of the Line Islands, Equatorial Pacific Ocean CRUISE KM1009 May 17, to June 16, 2010 Pago Pago, American Samoa to Honolulu, HI


The Arctic Research Of The Composition Of The Troposphere From Aircraft And Satellites (Arctas) Mission: Design, Execution, And First Results, D J. Jacob, J H. Crawford, H Maring, A D. Clarke, Jack E. Dibb, L K. Emmons, R A. Ferrare, C A. Hostetler, Phil Russell, H B. Singh, A M. Thompson, G E. Shaw, E Mccauley, Judith Pederson, Jenny Fisher Jun 2010

The Arctic Research Of The Composition Of The Troposphere From Aircraft And Satellites (Arctas) Mission: Design, Execution, And First Results, D J. Jacob, J H. Crawford, H Maring, A D. Clarke, Jack E. Dibb, L K. Emmons, R A. Ferrare, C A. Hostetler, Phil Russell, H B. Singh, A M. Thompson, G E. Shaw, E Mccauley, Judith Pederson, Jenny Fisher

Earth Sciences

The NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was conducted in two 3-week deployments based in Alaska (April 2008) and western Canada (June–July 2008). Its goal was to better understand the factors driving current changes in Arctic atmospheric composition and climate, including (1) influx of mid-latitude pollution, (2) boreal forest fires, (3) aerosol radiative forcing, and (4) chemical processes. The June–July deployment was preceded by one week of flights over California (ARCTAS-CARB) focused on (1) improving state emission inventories for greenhouse gases and aerosols, (2) providing observations to test and improve models …


Structure And Oscillatory Multilayer Relaxation Of The Bismuth (100) Surface, J. Sun, J. Wang, J. Wells, Y. M. Koroteev, G. Bihlmayer, E. V. Chulkov, Ph Hofmann, Karsten Pohl Jun 2010

Structure And Oscillatory Multilayer Relaxation Of The Bismuth (100) Surface, J. Sun, J. Wang, J. Wells, Y. M. Koroteev, G. Bihlmayer, E. V. Chulkov, Ph Hofmann, Karsten Pohl

Physics & Astronomy

We present a combined experimental and theoretical study of the surface structure of single crystal Bi(100) via scanning tunneling microscopy (STM), low-energy electron diffraction intensity versus energy (LEED-IV) analysis and density functional theory (DFT). We find that the surface is unreconstructed and shows an unusually large oscillatory multilayer relaxation down to the sixth layer. This unexpected behavior will be explained by a novel mechanism related to the deeply penetrating electronic surface states. STM reveals wide (100) terraces, which are separated by two-layer high steps in which the shorter of the two interlayer spacings is terminating this surface, consistent with the …


Modeling Radiation Belt Radial Diffusion In Ulf Wave Fields: 2. Estimating Rates Of Radial Diffusion Using Combined Mhd And Particle Codes, Chia-Lin L. Huang, Harlan E. Spence, Mary K. Hudson, Scot R. Elkington Jun 2010

Modeling Radiation Belt Radial Diffusion In Ulf Wave Fields: 2. Estimating Rates Of Radial Diffusion Using Combined Mhd And Particle Codes, Chia-Lin L. Huang, Harlan E. Spence, Mary K. Hudson, Scot R. Elkington

Physics & Astronomy

[1] Quantifying radial transport of radiation belt electrons in ULF wave fields is essential for understanding the variability of the trapped relativistic electrons. To estimate the radial diffusion coefficients (DLL), we follow MeV electrons in realistic magnetospheric configurations and wave fields calculated from a global MHD code. We create idealized pressure-driven MHD simulations for controlled solar wind velocities (hereafter referred to as pressure-driven Vx simulations) with ULF waves that are comparable to GOES data under similar conditions, by driving the MHD code with synthetic pressure profiles that mimic the pressure variations of a particular solar wind velocity. The ULF wave …