Physical Sciences and Mathematics Commons^™

Florida Energy Assurance Plan, Niescja Turner, W Murtagh, K Guthrie, K Nykyri, W Radasky, E Senkowicz

Niescja E. Turner

No abstract provided.

Reconciliation Of The Substorm Onset Determined On The Ground, In The Equatorial Magnetosphere, And At The Polar Spacecraft, P Toivanen, D Baker, W Peterson, H Singer, Niescja Turner, X Li, K Kauristie, M Syrjasuo, A Keiling, C Kletzing, C Russell

Niescja E. Turner

An isolated substorm on Oct. 17, 1997 during a close conjunction of the Polar spacecraft and the ground-based MIRACLE network is studied in detail. We identify signatures of substorm onset in the plasma sheet midway between the ionosphere and the equatorial plasma sheet, determine their timing relative to the ground signatures, and discuss their counterparts on the ground and in the equatorial plasma sheet. The substorm onset is determined as the negative bay onset at 2040:42(≠ 5 sec) UT coinciding with the onset of auroral precipitation, energization of plasma sheet electrons at Polar, and strong magnetic field variations perpendicular to …

Energy Dissipation During A Geomagnetic Storm: May 1998, T Pulkkinen, N Ganushkina, E Kallio, G Lu, D Baker, Niescja Turner, T Fritz, J Fennell, J Roeder

Niescja E. Turner

The energy input to the magnetosphere and its dissipation in the inner magnetosphere during a storm on May 2-9, 1998 is discussed. The methods to evaluate the energy input and the energy dissipation into the ionospheric Joule heat and the ring current are reviewed. It is shown that the energy dissipated in the ionosphere during individual substorms is proportional to the energy input during the same period. However, during very large energy input, the energy dissipation into the ionosphere seems to grow only slowly, and thus there seems to be a limit to how much energy can be dissipated via …

The Magnetic Field Induced By A Lightning Strikes Indirect Effect Double Exponential Current Waveform, S Meredith, S Earles, I Kostanic, Niescja Turner

Niescja E. Turner

Problem statement: Develop a new formula which describes the magnetic field induced by a lightning strike's indirect effect double exponential current waveform. Approach: A novel approach for developing a closed-form solution for the magnetic field from the indirect effect double exponential current waveform will be presented. In the literature, models typically employ the pulse waveform to derive the corresponding electromagnetic fields. However, given the Department of Defense (DoD) has incorporated the double exponential current waveform as part of their "Electromagnetic Environmental Effects Requirements For Systems", we felt it important to develop a solution for the magnetic field which utilized this …

Seasonal And Diurnal Variation Of Geomagnetic Activity: Revised Dst Versus External Drivers, L V.T Hakkinen, T I. Pulkkinen, R J. Pirjola, H Nevanlinna, E I. Tanskanen, Niescja E. Turner

Niescja E. Turner

Daily and seasonal variability of long time series of magnetometer data from Dst stations is examined. Each station separately shows a local minimum of horizontal magnetic component near 18 local time (LT) and weakest activity near 06 LT. The stations were found to have different baselines such that the average levels of activity differed by about 10 nT. This effect was corrected for by introducing a new “base method” for the elimination of the secular variation. This changed the seasonal variability of the Dst index by about 3 nT. The hemispheric differences between the annual variation (larger activity during local …

Energetics Of Magnetic Storms Driven By Corotating Interaction Regions: A Study Of Geoeffectiveness, Niescja E. Turner, E J. Mitchell, D J. Knipp, B A. Emery

Niescja E. Turner

We investigate the energetics of magnetic storms associated with corotating interaction regions (CIRs). We analyze 24 storms driven by CIRs and compare to 18 driven by ejecta-related events to determine how they differ in overall properties and in particular in their distribution of energy. To compare these different types of events, we look at events with comparable input parameters such as the epsilon parameter and note the properties of the resulting storms. We estimate the energy output by looking at the ring current energy along with ionospheric Joule heating derived from the PC and Dst indices. We also include the …

Energy Transport And Dissipation In The Magnetosphere During Geomagnetic Storms, D Baker, Niescja Turner, T Pulkkinen

Niescja E. Turner

Major geomagnetic storms represent a significant dissipation of energy by the magnetosphere. The energy is derived from the solar wind flow and the subsequent powerful conversion of that energy takes several different forms. Ring current injection and decay, ionospheric Joule heating, particle precipitation into the atmosphere, and several related physical processes are exhibited clearly in large storm events. The modern-day constellation of operating spacecraft gives an unprecedented opportunity to study magnetic storm processes and energetics. This paper focuses on recent coronal mass ejection (CME) events that have been well-observed near the sun. These disturbances are followed from the sun to …

Evaluation Of The Tail Current Contribution To Dst, Niescja Turner, D Baker, T Pulkkinen, R Mcpherron

Niescja E. Turner

The Dst index is produced using low-latitude ground magnetic field measurements and frequently is used as an estimate of the energy density of the ring current carried mainly by energetic (∼10-200 keV) ions relatively close to the Earth. However, other magnetospheric current systems can cause field perturbations at the Earth's surface: for example, dayside magnetopause currents are known to contribute to the Dst index. It has also been suggested that the nightside tail current sheet can significantly affect the Dst index during high magnetic activity periods when the currents are intense and flow relatively close to the Earth. In this …

A New Method To Describe Image Theory For An Imperfect Conductor, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

Problem statement: Modify the equations associated with image theory in order to account for perfect and imperfect conductors. Approach: A novel approach for describing the application of image theory for an imperfect conductive surface was presented. The method presented here purposely downplays the physics of how image theory was employed to account for a charge which is in the presence of an imperfect conductive surface. In turn, it adopted an approach which focused on the geometry that existed between the charged particle and surface ground. In doing so, the proposed method formulated a solution that had minimized the complexity of …

Geoefficiency And Energy Partitioning In Cir-Driven And Cme-Driven Storms, Niescja Turner, W Cramer, S Earles, B Emery

Niescja E. Turner

Magnetic storms due to corotating interaction regions (CIRs) have been shown to elicit different responses in the magnetosphere than those prompted by other types of solar wind driving conditions such as coronal mass ejections (CMEs). In particular, CIRs provoke a much weaker response in ground magnetometer data (Dst), possibly indicative of a weaker ring current. They also last many days longer than the CME events, yet over these longer events they couple a great deal of energy, sometimes comparable to that involved in typically larger-Dst CME events. It may seem at first that the weaker driving of CIR events must …

A New Method For Describing The Horizontal Electric Field Induced By A Lightning Strike Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

No abstract provided.

Effects Of Different Geomagnetic Storm Drivers On The Ring Current: Crcm Results, W D. Cramer, Niescja E. Turner, M C. Fok, N Y. Buzulukova

Niescja E. Turner

The storm-time magnetic disturbance at the Earth's equator, as commonly measured by the Dst index, is induced by currents in the near-Earth magnetosphere. The ring current is generally considered the most important contributor, but other magnetospheric currents have also been found to have significant effects. Of the two main types of solar geomagnetic storm drivers, Coronal Mass Ejections (CMEs) tend to have a much greater impact on Dst than Corotating Interaction Regions (CIRs). Ring current models have been found to underestimate Dst, particularly during storms driven by CIRs. One possible explanation is that the models neglect to handle some aspect …

Timing Of Substorm-Associated Auroral Oscillations, P Martin, Niescja E. Turner, J Wanliss

Niescja E. Turner

Previous studies have shown that auroral luminosity oscillations are often associated with substorms. Here we examine photometer data for the magnetospheric substorm on April 1, 2000 (expansive phase onset at 0525 UT) to study the detailed timing of the auroral oscillations relative to onset. Accurate timing information for the periodicities in the photometer data were determined using the wavelet transform. We find that the oscillations occur primarily during the recovery phase. Copyright © The Society of Geomagnetism and Earth

Geoeffectiveness Of Cir And Cme Events: Factors Contributing To Their Differences, L Laughlin, Niescja Turner

Niescja E. Turner

Recent work has shown that solar wind-magnetosphere coupling is moreefficient for CIR-driven events than for CME-driven events. The studyherein looks into the individual physical parameters of Corotating Interaction Regions (CIRs) and Coronal Mass Ejections (CMEs) and looks to isolate particular characteristics that leads to greater coupling ofenergy from the solar wind into the magnetosphere for certain classesof magnetic storms. While it is clear that these two types of events are distinct in their outcome, it is not known what in the nature of the events leads to these different results. The variation level in the z-component of the Interplanetary Magnetic …

Correlation Of Changes In The Outer-Zone Relativistic-Electron Population With Upstream Solar Wind Measurements, J Blake, D Baker, Niescja Turner, K Ogilvie, R Lepping

Niescja E. Turner

A study has been made of the correlation of the population of relativistic electrons in the outer-zone magnetosphere with the properties of the solar wind (speed, density, magnetic field) during a solar minimum period. The study is based upon observations made in the Spring of 1995 with sensors aboard 1994-026 and WIND. It is found that a large relativistic electron enhancement depends upon a substantial solar-wind speed increase associated with precursor solar-wind density enhancement, and, in particular, upon a southward turning of the interplanetary magnetic field

Ring Current Ion Composition During Solar Minimum And Rising Solar Activity: Polar/Cammice/Mics Results, T Pulkkinen, N Ganushkina, D Baker, Niescja Turner, J Fennell, J Roeder, T Fritz, M Grande, B Kellett, G Kettmann

Niescja E. Turner

This paper shows statistical results of the ring current ion composition and its variability as a function of solar cycle and magnetospheric activity for 3 < L < 8. Spin-averaged energetic particle (1-200 keV) measurements from Polar are combined with geomagnetic indices as well as solar wind and interplanetary observations from the Wind spacecraft during a period from September 1996 to March 1999. The statistics are performed both for time-averaged values for all periods as well as for peak flux values during geomagnetic storms (defined as Dst < -50 nT) that occurred during this period. The average O+ energy density increases by about …

Ring Current Development In Mhd Simulations, R Bruntz, R Lopez, Niescja Turner, M Wiltberger, J Lyon

Niescja E. Turner

A signature feature of magnetic storms is the development of a ring current. Recent ideas on ring current formation suggest that during the main phase of storms the ring current is primarily asymmetric, becoming symmetric only during the recovery phase. In this paper, we examine ring current formation during a magnetic storm using global magnetohydrodynamic simulations of the interaction between the solar wind and the magnetosphere. The magnetohydrodynamic simulation uses solar wind data as a boundary condition, allowing the modeling of actual events. The event modeled here is the January 1997 storm. Although the code does not develop a true …

Energy Content Of The Stormtime Ring Current, Niescja Turner, D Baker, T Pulkkinen, J Roeder, J Fennell, V Jordanova

Niescja E. Turner

Given the important role the ring current plays in magnetospheric energetics, it is essential to understand its strength and evolution in disturbed times. There are currently three main methods for deducing the strength of the ring current: measuring ground magnetic perturbations, measuring high-altitude magnetic perturbations, or directly measuring ring current particles. The use of ground magnetometers is the most convenient, and many use the ground magnetometer-derived Dst index as a proxy for the ring current. Recent work suggests, however, that a substantial portion of Dst may not be caused only by the ring current but also by local induction effects …

How Lightning Tortuosity Affects The Electromagnetic Fields By Augmenting Their Effective Distance, S Meredith, S Earles, I Kostanic, Niescja Turner, C Otero

Niescja E. Turner

A novel approach for developing the electromagnetic fields from a lightning return stroke which follows a tortuous path will be presented. The proposed model is unique in that it recognizes that the symmetrical tortuosity of lightning directly impacts the observable distance r, which in turn, alters the resulting electromagnetic fields. In the literature, lightning return stroke models typically employ the assumption that the cloud-to-ground path is straight. Although this assumption yields fairly consistent results across an array of varying approaches, it does not account for lightning's natural physical appearance. Furthermore, straight-line models only account for the cloud-to-ground discharges and do …

Solar Wind-Magnetosphere Coupling And Global Energy Budgets In The Earth's Magnetosphere, Niescja Turner

Niescja E. Turner

This thesis focuses on two different but related topics in magnetospheric physics: solar wind coupling into the magnetosphere and energy deposition within the magnetosphere. I first address solar wind coupling in a study of the interplanetary electric field and its influence on the high-altitude polar cap. I use POLAR EFI data and find changes in the electric field over the polar cap in response to sharp deviations in the interplanetary electric field. Then the focus is shifted towards estimation of global energy budgets. Estimates have been made in the past regarding the relative importance of auroral processes, ring current injection, …

High-Altitude Polar Cap Electric Field Responses To Southward Turnings Of The Interplanetary Magnetic Field, Niescja Turner, D Baker, T Pulkkinen, H Singer, F Mozer, R Lepping

Niescja E. Turner

Interplanetary electric field coupling with the magnetosphere has been analyzed predominantly using data from the Wind magnetometer and the Polar electric field instrument. The coupling was investigated using the Polar Electric Field Instrument (EFI) to measure the electric field in the northern polar cap immediately following sharp southward turnings of the IMF as observed by Wind. Southward turnings were chosen which exhibited a sudden change of the IMF north-south component from BZ > 0 to BZ < 0 (GSM coordinates) after an hour or more of relatively stable conditions, and for which Polar was in the northern polar cap. These BZ changes …

The Horizontal Electric Field Induced By A Lightning Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

Problem statement: Develop a new formula which describes the horizontal electric field induced by a lightning return stroke in contact with an imperfect conductive surface. Approach: A new method for describing the horizontal electric field induced by a lightning return stroke will be presented. The method presented here had utilized an approach which purposely downplayed the physics of how image theory was employed in the presence of an imperfect conductive surface. It did so by adopting a technique which had focused on the geometry that existed between the lightning channel and surface ground. In doing so, new expressions for surface …

Α-Hydroxyhippuric Acid Derivatives: Ph-Dependent Aqueous Kinetics And Buffer Catalysis., Kati Feken

Theses and Dissertations

Synthesis and kinetic investigations of the aqueous breakdown of α-hydroxyhippuric acid derivatives as a function of pH were performed to acquire an understanding of the reactivity of this biologically relevant carbinolamide functionality.

An Apparent Angular Unconformity In Western Connecticut, Stanley Schleifer, Nazrul I. Khandaker, Adisa Charles, Hernando Martinez, Shirley Jackson, Chiemeka Ihebom

Publications and Research

The recent extension, to the north, of the U. S. Route 7 ‘superhighway’ in the town of Brookfield, Connecticut has involved the excavation of crystalline bedrock of lower Paleozoic to upper Proterozoic age in the area. The road cuts produced by this excavation have exposed some interesting features of structure and lithology. An outcrop, observed by the authors off the east side of route 7, at grid coordinates 41.482444 N, 73.415307 W is of particular interest. It appears, to the casual observer to be an angular unconformity. Maps and publications regarding this area of Western Connecticut support the likelihood of …

Using Open Datasets And Simulations In Laboratories, Jim Crumley

Physics Faculty Publications

While advances in instrumentation physics have made many areas more accessible to undergraduate physics laboratories, other areas are still beyond reach. Open data sets and simulations can open up some other frontiers of physics, such as Space Physics and Astronomy. In this talk, I will give an overview of some resources for open data and simulations, and then describe my experiences using these tools in both introductory and advanced labs in our curriculum.

Community College Consortium Promotes Open Educational Practices Through Outreach And Collaboration, Una T. Daly, Lisa Storm, Barbara Illowsky

SJSU Open Access Conference

The Community College Consortium for Open Educational Resources (CCCOER) is a community of practice focused on awareness and promoting best practices for OER discovery and adoption including open textbooks, open MOOCs, and open repositories to enhance learning and teaching. Through monthly outreach webinars with OER leaders and online advisory meetings, the community shares their projects and expertise encouraging collaboration across institutions, disciplines, and higher education sectors. Hear from the consortium director and two leaders of the community college OER movement.

• Una Daly, Director of Community College Outreach, OpenCourseWare Consortium. Building a community to promote awareness and shared knowledge of …

Fearless: Heather Ipsen, Heather Ipsen

SURGE

In celebration of Sustainability Week on campus, we proudly feature Heather Ipsen ’16 who has fearlessly raised awareness for the environmental issues about which she’s passionate and started a group on campus to better facilitate dialogue between sustainability groups. [excerpt]

Mobimed: Framework For Rapid Application Development Of Medical Mobile Apps, Frank Hernadez

FIU Electronic Theses and Dissertations

In the medical field images obtained from high definition cameras and other medical imaging systems are an integral part of medical diagnosis. The analysis of these images are usually performed by the physicians who sometimes need to spend long hours reviewing the images before they are able to come up with a diagnosis and then decide on the course of action. In this dissertation we present a framework for a computer-aided analysis of medical imagery via the use of an expert system. While this problem has been discussed before, we will consider a system based on mobile devices.

Since the …

Effects Of Water Development On Arid Land Freshwater Ecosystems, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

This presentation focuses on the Columbia Basin Project

Emerging Contaminants In Oregon Coastal Waters: Hotspots, Landscape Drivers And Synergistic Effects On Bivalves, Elise F. Granek, William Fish, Angela L. Strecker

Environmental Science and Management Faculty Publications and Presentations

This presentation focuses on the following research questions:

• Types and levels of contaminants of emerging concern (CECs) in Oregon’s coastal ocean?
• Levels of CECs in native and commercial oysters?
• Ecological effects (growth, reproductive output, etc.) of these contaminants in marine bivalves?