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Butterfly Pitch-Angle Distribution Of Relativistic Electrons In The Outer Radiation Belt: Evidence Of Nonadiabatic Scattering, Nikolai O. Artemyev, O. V. Agapitov, F. S. Mozer, Harlan E. Spence

Physics & Astronomy

In this paper we investigate the scattering of relativistic electrons in the nightside outer radiation belt (around the geostationary orbit). We consider the particular case of low geomagnetic activity (|Dst|<20 nT), quiet conditions in the solar wind, and absence of whistler wave emissions. For such conditions we find several events of Van Allen probe observations of butterfly pitch angle distributions of relativistic electrons (energies about 1–3 MeV). Many previous publications have described such pitch angle distributions over a wide energy range as due to the combined effect of outward radial diffusion and magnetopause shadowing. In this paper we discuss another mechanism that produces butterfly distributions over a limited range of electron energies. We suggest that such distributions can be shaped due to relativistic electron scattering in the equatorial plane of magnetic field lines that are locally deformed by currents of hot ions injected into the inner magnetosphere. Analytical estimates, test particle simulations, and observations of the AE index support this scenario. We conclude that even in the rather quiet magnetosphere, small scale (magnetic local time (MLT)-localized) injection of hot ions from the magnetotail can likely influence the relativistic electron scattering. Thus, observations of butterfly pitch angle distributions can serve as an indicator of magnetic field deformations in the nightside inner magnetosphere. We briefly discuss possible theoretical approaches and problems for modeling such nonadiabatic electron scattering.

Evolution Of Brown Carbon In Wildfire Plumes, Haviland Forrister, Jiumeng Liu, Jack E. Dibb, Eric Scheuer, Luke D. Ziemba, Kenn L. Thornhill, Bruce Anderson, Glenn Diskin, Anne E. Perring, Joshua P. Schwarz, Pedro Campuzano-Jost, Douglas A. Day, Brett B. Palm, Jose L. Jimenez, Athanasios Nenes, Rodney J. Weber

Earth Sciences

Particulate brown carbon (BrC) in the atmosphere absorbs light at subvisible wavelengths and has poorly constrained but potentially large climate forcing impacts. BrC from biomass burning has virtually unknown lifecycle and atmospheric stability. Here, BrC emitted from intense wildfires was measured in plumes transported over 2 days from two main fires, during the 2013 NASA SEAC4RS mission. Concurrent measurements of organic aerosol (OA) and black carbon (BC) mass concentration, BC coating thickness, absorption Ångström exponent, and OA oxidation state reveal that the initial BrC emitted from the fires was largely unstable. Using back trajectories to estimate the transport time indicates …

Lightning Strikes Twice, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Evaluation Of A Computing And Engineering Outreach Program For Girls In Grades 8–10, Mihaela C. Sabin, Paul Snow, Mary Laturnau

Applied Engineering and Sciences Scholarship

An outreach program of workshops and guided group activities for New Hampshire's eighth, ninth and tenth grade girls was offered to stimulate the girls' interest in computing and engineering coursework and careers. Attitude changes before and after participation were measured using a survey instrument adapted from one developed by the Georgia Tech's Institute for Computing and Education. Eight attitudinal themes were surveyed. With suitable adjustments for simultaneous testing of multiple hypotheses, statistically significant changes with moderate effect sizes were detected for three of the themes: enjoyment of technology-related activities, motivation to succeed in technical problem solving, and intention to persist …

Crop Rotational Diversity Enhances Belowground Communities And Functions In An Agroecosystem, L. K. Tiemann, A. Stuart Grandy, E. E. Atkinson, E. Marin-Spiotta, M. D. Mcdaniel

Faculty Publications

Biodiversity loss, an important consequence of agricultural intensification, can lead to reductions in agroecosystem functions and services. Increasing crop diversity through rotation may alleviate these negative consequences by restoring positive aboveground–belowground interactions. Positive impacts of aboveground biodiversity on belowground communities and processes have primarily been observed in natural systems. Here, we test for the effects of increased diversity in an agroecosystem, where plant diversity is increased over time through crop rotation. As crop diversity increased from one to five species, distinct soil microbial communities were related to increases in soil aggregation, organic carbon, total nitrogen, microbial activity and decreases in …

Modification Of Electronic Surface States By Graphene Islands On Cu(111), Shawna M. Hollen, G A. Gambrel, S J. Tjung, N M. Santagata, Ezekiel Johnston-Halperin, Jay A. Gupta

Physics & Astronomy

We present a study of graphene/substrate interactions on ultrahigh-vacuum-grown graphene islands with minimal surface contamination using in situ low-temperature scanning tunneling microscopy. We compare the physical and electronic structure of the sample surface with atomic spatial resolution on graphene islands versus regions of bare Cu(111) substrate. We find that the Rydberg-like series of image potential states is shifted toward lower energy over the graphene islands relative to Cu(111), indicating a decrease in the local work function, and the resonances have a much smaller linewidth, indicating reduced coupling to the bulk. In addition, we show the dispersion of the occupied Cu(111) …

Disappearance Of Plasmaspheric Hiss Following Interplanetary Shock, Zhenpeng Su, Hui Zhu, Fuliang Xiao, Yuming Wang, Chao Shen, Min Zhang, Shui Wang, C A. Kletzing, W. S. Kurth, G. B. Hospodarsky, Harlan E. Spence, Geoffrey Reeves, H. O. Funsten, J. B. Blake, D. N. Baker, J. R. Wygant

Physics & Astronomy

Abstract Plasmaspheric hiss is one of the important plasma waves controlling radiation belt dynamics. Its spatiotemporal distribution and generation mechanism are presently the object of active research. We here give the first report on the shock-induced disappearance of plasmaspheric hiss observed by the Van Allen Probes on 8 October 2013. This special event exhibits the dramatic variability of plasmaspheric hiss and provides a good opportunity to test its generation mechanisms. The origination of plasmaspheric hiss from plasmatrough chorus is suggested to be an appropriate prerequisite to explain this event. The shock increased the suprathermal electron fluxes, and then the enhanced …

Yvette Olivia George ’71, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Mathematics Professor Kevin Short Inducted As National Academy Of Inventors Fellow, Brooks Payette

UNH Today Archive

No abstract provided.

Unraveling The Drivers Of The Storm Time Radiation Belt Response, E. K.J. Kilpua, H. Hietala, D. L. Turner, H. E.J. Koskinen, T. I. Pulkkinen, J. V. Rodriguez, Geoffrey Reeves, S. Claudepierre, Harlan E. Spence

Physics & Astronomy

We present a new framework to study the time evolution and dynamics of the outer Van Allen belt electron fluxes. The framework is entirely based on the large-scale solar wind storm drivers and their substructures. The Van Allen Probe observations, revealing the electron flux behavior throughout the outer belt, are combined with continuous, long-term (over 1.5 solar cycles) geosynchronous orbit data set from GOES and solar wind measurements A superposed epoch analysis, where we normalize the timescales for each substructure (sheath, ejecta, and interface region) allows us to avoid smearing effects and to distinguish the electron flux evolution during various …

Energetic, Relativistic And Ultra-Relativistic Electrons: Comparison Of Long-Term Verb Code Simulations With Van Allen Probes Measurements, A. Drozdov, Y. Y. Shprits, K. Orlova, A. C. Kellerman, D. A. Subbotin, D. N. Baker, Harlan E. Spence, Geoffrey Reeves

Physics & Astronomy

In this study, we compare long-term simulations performed by the Versatile Electron Radiation Belt (VERB) code with observations from the Magnetic Electron Ion Spectrometer and Relativistic Electron-Proton Telescope instruments on the Van Allen Probes satellites. The model takes into account radial, energy, pitch angle and mixed diffusion, losses into the atmosphere, and magnetopause shadowing. We consider the energetic (>100 keV), relativistic (~0.5–1 MeV), and ultrarelativistic (>2 MeV) electrons. One year of relativistic electron measurements (μ = 700 MeV/G) from 1 October 2012 to 1 October 2013 are well reproduced by the simulation during varying levels of geomagnetic …

Analysis Of Plasmaspheric Hiss Wave Amplitudes Inferred From Low-Altitude Poes Electron Data: Technique Sensitivity Analysis, M. De Soria-Santacruz, W. Li, R. M. Thorne, Q. Ma, J. Bortnik, B. Ni, C A. Kletzing, W. S. Kurth, G. B. Hospodarsky, Harlan E. Spence, Geoffrey Reeves, J. B. Blake, Joseph F. Fennell

Physics & Astronomy

A novel technique capable of inferring wave amplitudes from low-altitude electron measurements from the Polar Operational Environmental Satellites (POES) spacecraft has been previously proposed to construct a global dynamic model of chorus and plasmaspheric hiss waves. In this paper we focus on plasmaspheric hiss, which is an incoherent broadband emission that plays a dominant role in the loss of energetic electrons from the inner magnetosphere. We analyze the sensitivity of the POES technique to different inputs used to infer the hiss wave amplitudes during three conjunction events with the Van Allen Probes. These amplitudes are calculated with different input models …

Do Footprint-Based Cafe Standards Make Car Models Bigger?, Brianna Marie Jean

Economics

Corporate Average Fuel Economy (CAFE) standards have historically been set equal across all manufacturer fleets of the same type. Concerns about varying costs across firms and safety implications of standards that are set homogeneously across firms and models resulted in a policy shift towards footprint-based standards. Under this type of standard, individual car models face targets based on the size of the area between the wheelbase and wheel track, so that larger models face less stringent standards, and manufacturers who make, on average, larger cars will face a lighter fleet standard. Theoretical models have shown that this type of policy …

Excess Body Weight And Gait Influence Energy Cost Of Walking In Older Adults, Dain P. Laroche, Nise R. Marques, Heidi N. Shumila, Christopher R. Logan, Robyn St Laurent, Mauro Gonçalves

Kinesiology

Purpose: To study how excess body weight influences the energy cost of walking (Cw) and determine if overweight and obese older adults self-select stride frequency to minimize Cw.

Methods: Using body mass index (BMI) men and women between the ages of 65–80 yr were separated into normal weight (NW, BMI ≤ 24.9 kg m−2, n = 13) and overweight-obese groups (OWOB, BMI ≥25.0 kg m−2, n = 13). Subjects walked at 0.83 m s−1 on an instrumented treadmill that recorded gait parameters, and completed three, six-minute walking trials; at preferred stride frequency (PSF), at +10% PSF, and at −10% PSF. …

Grad Students Receive Prestigious Nsf Fellowships, Jeanne Sokolowski

UNH Today Archive

No abstract provided.

Biology Student Michael Neveu Named 2015 Commencement Student Speaker, Kassidy Taylor

UNH Today Archive

No abstract provided.

The New Hampshire, Vol. 104 [105], No. 47 (Apr. 27, 2015), The New Hampshire

The New Hampshire Print Edition

An independent student produced newspaper from the University of New Hampshire. This volume was printed as 104, but it is the 105th volume in the series. This was corrected in pencil.

Graduating Biology Major Pursues Dentistry Career, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

The New Hampshire, Vol. 104 [105], No. 42 (Apr. 9, 2015), The New Hampshire

The New Hampshire Print Edition

An independent student produced newspaper from the University of New Hampshire. This volume was printed as 104, but it is the 105th volume in the series. This was corrected in pencil.

Unh Launches Stem Teachers Collaborative, Joins National Effort To Prepare 100,000 Excellent Stem Teachers By 2021, Erika Mantz

Media Relations

No abstract provided.

Unh Launches Stem Teachers Collaborative, Joins National Effort To Prepare 100,000 Excellent Stem Teachers By 2021, Unh Communications And Public Affairs

UNH Today Archive

No abstract provided.

Taking A Deeper Look Into The Lives Of Disadvantaged Children Through Visual Content Analysis, Julianne Shimer

Inquiry Journal 2015

Asking children to draw a picture of family life is a simple and efficient way to assess their mental health.Children enjoy this activity and are more at ease as compared to filling out a questionnaire or having a formal interview. This past summer, I joined a research project in Ireland called the Healthy Schools Programme (HSP) that did just that. In total, 220 drawings of family life were collected from disadvantaged children aged eight to twelve years. The drawings gathered from this group were analyzed using a technique known as visual content analysis. This method involves examining drawings, pictures, or …

The Promise And Peril Of Intensive-Site-Based Ecological Research: Insights From The Hubbard Brook Ecosystem Study, Timothy J. Fahey, Pamela H. Templer, Bruce T. Anderson, John J. Battles, John L. Campbell, Charles T. Driscoll, Anthony R. Fusco, Mark B. Green, Karim-Aly S. Karrim, Nicholas L. Rodenhouse, Lindsay E. Rustad, Paul G. Schaberg, Matthew A. Vadeboncoeur

All Materials

Abstract.

Ecological research is increasingly concentrated at particular locations or sites. This trend reflects a variety of advantages of intensive, site-based research, but also raises important questions about the nature of such spatially delimited research: how well does site based research represent broader areas, and does it constrain scientific discovery?We provide an overview of these issues with a particular focus on one prominent intensive research site: the Hubbard Brook Experimental Forest (HBEF), New Hampshire, USA. Among the key features of intensive sites are: long-term, archived data sets that provide a context for new discoveries and the elucidation of ecological mechanisms; …

Study Of Emic Wave Excitation Using Direct Ion Measurements, Kyungguk Min, Kaijun Liu, J. Bonnell, Aaron W. Breneman, Richard E. Denton, H. O. Funsten, Joerg-Micha Jahn, C A. Kletzing, W. S. Kurth, B. A. Larsen, Geoffrey Reeves, Harlan E. Spence, J. R. Wygant

Physics & Astronomy

With data from Van Allen Probes, we investigate electromagnetic ion cyclotron (EMIC) wave excitation using simultaneously observed ion distributions. Strong He band waves occurred while the spacecraft was moving through an enhanced density region. We extract from helium, oxygen, proton, and electron mass spectrometer measurement the velocity distributions of warm heavy ions as well as anisotropic energetic protons that drive wave growth through the ion cyclotron instability. Fitting the measured ion fluxes to multiple sinm-type distribution functions, we find that the observed ions make up about 15% of the total ions, but about 85% of them are still missing. By …

International Collaboration In Physics Research: A Summer At Cern, Herbie Smith

Inquiry Journal 2015

During the summer of 2014, after my junior year as a physics major at the University of New Hampshire, I took part in a nine-week Research Experience for Undergraduates sponsored by the University of Michigan and the National Science Foundation. During the program, I lived and worked at the European Organization for Nuclear Research (CERN) just outside of Geneva,Switzerland. CERN is home to the largest particle collider in the world, the Large Hadron Collider (LHC), and is the world’s leading particle physics laboratory. As a summer student, I attended daily lectures on particle physics from leading experts in the field, …

Spring 2015, Fulbright Scholars Program, Lynette Hentges

UNH International Educator Newsletter

No abstract provided.

Unh Joins U.S. Engineering Schools In Transforming Engineering Education, Brooks Payette

Media Relations

No abstract provided.

Van Allen Probes Show That The Inner Radiation Zone Contains No Mev Electrons: Ect/Mageis Data, J. F. Fennell, S. Claudepierre, J. B. Blake, T. P. O'Brien, J. H. Clemmons, D. N. Baker, Harlan E. Spence, Geoffrey Reeves

Physics & Astronomy

Abstract

We present Van Allen Probe observations of electrons in the inner radiation zone. The measurements were made by the Energetic Particle, Composition, and Thermal Plasma/Magnetic Electron Ion Spectrometer (MagEIS) sensors that were designed to measure electrons with the ability to remove unwanted signals from penetrating protons, providing clean measurements. No electrons >900 keV were observed with equatorial fluxes above background (i.e., >0.1 el/(cm² s sr keV)) in the inner zone. The observed fluxes are compared to the AE9 model and CRRES observations. Electron fluxes <200 keV exceeded the AE9 model 50% fluxes and were lower than the higher-energy model fluxes. Phase space density radial profiles for 1.3 ≤ L* < 2.5 had mostly positive gradients except near L*~2.1, where the profiles for μ = 20–30 MeV/G were flat …

On The Use Of Drift Echoes To Characterize On-Orbit Sensor Discrepancies, T. P. O'Brien, S. Claudepierre, M. Looper, J. B. Blake, J. F. Fennell, J. H. Clemmons, J. Roeder, S. G. Kanekal, J. W. Manweiler, D. G. Mitchell, M. Gkioulidou, L. J. Lanzerotti, Harlan E. Spence, Geoffrey Reeves, D. N. Baker

Physics & Astronomy

No abstract provided.

Shock-Induced Prompt Relativistic Electron Acceleration In The Inner Magnetosphere, J. C. Foster, J. R. Wygant, M. K. Hudson, A. J. Boyd, D. N. Baker, P. J. Erickson, Harlan E. Spence

Physics & Astronomy

Abstract

We present twin Van Allen Probes spacecraft observations of the effects of a solar wind shock impacting the magnetosphere on 8 October 2013. The event provides details both of the accelerating electric fields associated with the shock and the response of inner magnetosphere electron populations across a broad range of energies. During this period, the two Van Allen Probes observed shock effects from the vantage point of the dayside magnetosphere at radial positions of L = 3 and L = 5, at the location where shock-induced acceleration of relativistic electrons occurs. The extended (~1 min) duration of the accelerating …