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Sample records for active auroral program

  1. Upper atmospheric effects of the hf active auroral research program ionospheric research instrument (HAARP IRI)

    SciTech Connect

    Eccles, V.; Armstrong, R.

    1993-05-01

    The earth's ozone layer occurs in the stratosphere, primarily between 10 and 30 miles altitude. The amount of ozone, O3, present is the result of a balance between production and destruction processes. Experiments have shown that natural processes such as auroras create molecules that destroy O. One family of such molecules is called odd nitrogen of which nitric oxide (NO) is an example. Because the HAARP (HF Active Auroral Research Program) facility is designed to mimic and investigate certain natural processes, a study of possible effects of HAARP on the ozone layer was conducted. The study used a detailed model of the thermal and chemical effects of the high power HF beam, which interacts with free electrons in the upper atmosphere above 50 miles altitude. It was found only a small fraction of the beam energy goes into the production of odd nitrogen molecules, whereas odd nitrogen is efficiently produced by auroras. Since the total energy emitted by HAARP in the year is some 200,000 times less than the energy deposited in the upper atmosphere by auroras, the study demonstrates that HAARP HF beam experiments will cause no measurable depletion of the earth's ozone layer.... Ozone, Ozone depletion, Ozone layer, Odd nitrogen, Nitric oxide, HAARP Emitter characteristics.

  2. Mapping auroral activity with Twitter

    NASA Astrophysics Data System (ADS)

    Case, N. A.; MacDonald, E. A.; Heavner, M.; Tapia, A. H.; Lalone, N.

    2015-05-01

    Twitter is a popular, publicly accessible, social media service that has proven useful in mapping large-scale events in real time. In this study, for the first time, the use of Twitter as a measure of auroral activity is investigated. Peaks in the number of aurora-related tweets are found to frequently coincide with geomagnetic disturbances (detection rate of 91%). Additionally, the number of daily aurora-related tweets is found to strongly correlate with several auroral strength proxies (ravg≈0.7). An examination is made of the bias for location and time of day within Twitter data, and a first-order correction of these effects is presented. Overall, the results suggest that Twitter can provide both specific details about an individual aurora and accurate real-time indication of when, and even from where, an aurora is visible.

  3. Do interplanetary Alfven waves cause auroral activity?

    NASA Technical Reports Server (NTRS)

    Roberts, D. Aaron; Goldstein, Melvyn L.

    1990-01-01

    A recent theory holds that high-intensity, long-duration, continuous auroral activity (HILDCAA) is caused by interplanetary Alfven waves propagating outward from the sun. A survey of Alfvenic intervals in over a year of ISEE 3 data shows that while Alfvenic intervals often accompany HILDCAAs, the reverse is often not true. There are many Alfvenic intervals during which auroral activity (measured by high values of the AE index) is very low, as well as times of high auroral activity that are not highly Alfvenic. This analysis supports the common conclusion that large AE values are associated with a southward interplanetary field of sufficient strength and duration. This field configuration is independent of the presence of Alfven waves (whether solar generated or not) and is expected to occur at random intervals in the large-amplitude stochastic fluctuations in the solar wind.

  4. The Utility of Auroral Image-based Activities Metrics

    NASA Technical Reports Server (NTRS)

    Germany, G.; Spann, J.; Deverapalli, C.; Hung, C.-C.

    2004-01-01

    Auroral activity indices such as Hemispheric Power and Auroral Boundary are currently key data products used for space weather predictions and nowcasting. However, these products are necessarily based on limited observations which must be extrapolated to provide global coverage. The advent of routine space-based auroral imaging in the last decade offers the seeming advantage of more detailed measures of auroral activity. Examples of image-derived products include energy deposition maps, oval location, cap size, and morphological classification. However, activity metrics derived from auroral images have shortcomings, as well. For example, limited fields-of-view and orbital motion prevent full coverage of the auroral regions. This paper will examine the utility of activity metrics derived h m auroral images for operational purposes. The eight-year collection of Polar UVI images databased in the UVI Online Search Tool (OST) will be used to illustrate the advantages and shortcomings of auroral activity metrics. The potential role of other currently-active imaging missions will also be examined and correlative studies to date using auroral imaging will be summarized.

  5. ENA diagnostics of auroral activity at Mars

    NASA Astrophysics Data System (ADS)

    Ip, W.-H.

    2012-04-01

    One prominent feature of solar wind - Mars interaction has to do with the presence of strong crustal magnetic fields, especially, in the southern hemisphere. This physical property has set Mars apart from Venus as far as the kinetic effect in detail. In this paper, we review briefly the recent particles-and-fields measurements at Mars in connection to the auroral activity driven by magnetic field reconnection between the crustal magnetic fields and the interplanetary fields. It is suggested that the subsolar ENA (energetic neutral atoms) jets discovered by the NPD instrument of Mars Express could be resulting from charge exchange effect of the shocked solar wind protons at the magnetopause-like regions of the Martian mini-magnetospheres and at the cusp regions of the crustal magnetic fields. It also means that ENA and LENA (low energy neutral atom) detectors could be important experiments for diagnostics of the auroral process unique to Mars, which might contribute to the overall atmospheric loss budget.

  6. A study of auroral activity in the nightside polar cap

    SciTech Connect

    Wu, Q.

    1989-01-01

    Using various ground observations at South Pole, Antarctica (invariant magnetic latitude -74{degree}) and its conjugate point, Frobisher Bay, Canada, the author has studied the following aspects of nightside polar cap auroral activity: the appearance and disappearance of polar cap auroras (diffuse and discrete) associated with substorms and interplanetary magnetic field (IMF) variations; auroral optical emission line intensities; and the seasonal variation of auroral conjugacy. The observations show that the polar cap auroras usually fade away before the expansive phase of a substorm and bright auroral arcs reach high latitude (-74{degree}) near the recovery phase. Just before the auroras fade away the discrete polar cap auroral arcs, which are usually on the poleward boundary of the diffuse aurora, intensify for 1 to 2 minutes. The observations also indicate the IMF may have stronger control over polar cap auroral activity than do substorms. A search for energy spectral variation of precipitating electrons using the intensities of 630.0 nm (0) and 427 nm (N{sub 2}{sup +}) auroral emission lines reveals no dramatic changes in the energy spectrum; instead, the data show possible atmospheric scattering and geometric effects on the photometric measurements while the bright auroral arc is moving into the polar cap. The conjugate observations show that the stormtime auroral electrojet current, which is associated with the bright auroral arc, in most cases reaches higher (lower) latitudes in the winter (summer) hemisphere. An asymmetric plasma sheet (with respect to the neutral sheet) is proposed, which expands deeper into the winter lobe, under a tilted geomagnetic dipole. Accordingly, the winter polar cap would have smaller area and the auroral electrojet would be at higher latitude.

  7. Tail reconnection region versus auroral activity inferred from conjugate ARTEMIS plasma sheet flow and auroral observations

    NASA Astrophysics Data System (ADS)

    Nishimura, Y.; Lyons, L. R.; Xing, X.; Angelopoulos, V.; Donovan, E. F.; Mende, S. B.; Bonnell, J. W.; Auster, U.

    2013-09-01

    sheet flow bursts have been suggested to correspond to different types of auroral activity, such as poleward boundary intensifications (PBIs), ensuing auroral streamers, and substorms. The flow-aurora association leads to the important question of identifying the magnetotail source region for the flow bursts and how this region depends on magnetic activity. The present study uses the ARTEMIS spacecraft coordinated with conjugate ground-based auroral imager observations to identify flow bursts beyond 45 RE downtail and corresponding auroral forms. We find that quiet-time flows are directed dominantly earthward with a one-to-one correspondence with PBIs. Flow bursts during the substorm recovery phase and during steady magnetospheric convection (SMC) periods are also directed earthward, and these flows are associated with a series of PBIs/streamers lasting for tens of minutes with similar durations to that of the series of earthward flows. Presubstorm onset flows are also earthward and associated with PBIs/streamers. The earthward flows during those magnetic conditions suggest that the flow bursts, which lead to PBIs and streamers, originate from further downtail of ARTEMIS, possibly from the distant-tail neutral line (DNL) or tailward-retreated near-Earth neutral line (NENL) rather than from the nominal NENL location in the midtail. We find that tailward flows are limited primarily to the substorm expansion phase. They continue throughout the period of auroral poleward expansion, indicating that the expansion-phase flows originate from the NENL and that NENL activity is closely related to the auroral expansion of the substorm expansion phase.

  8. Dayside Auroral Activity During Solar Maximum and Minimum Periods

    NASA Astrophysics Data System (ADS)

    Rawie, M.; Fasel, G. J.; Flicker, J.; Angelo, A.; Bender, S.; Alyami, M.; Sibeck, D. G.; Sigernes, F.; Lorentzen, D. A.; Green, D.

    2014-12-01

    It is well documented that the dayside auroral oval shifts equatorward when the interplanetary magnetic field (IMF) Bz-component turns southward [Burch, 1973; Akasofu, 1977; Horwitz and Akasofu, 1977; Sandholt et al., 1986, 1988]. During these periods of oval expansion dayside transients are observed to move away from the poleward edge of the auroral oval and drift poleward. These poleward-moving auroral forms are believed to be ionospheric signatures of dayside merging. The dayside auroral oval usually begins to contract when the interplanetary magnetic field turns sharply northward, Bz>0. Eighteen years of meridian scanning photometer (MSP) data from the Kjell Henriksen Observatory in Longyearbyen, Norway are analyzed. During the boreal winter the Sun is several degrees below the horizon. This permits optical observations throughout the daytime period. The MSP Data is selected two hours before and after local noon in Longyearbeyn. Solar wind data (solar wind pressure and speed, along with the IMF Bx, By, Bz components) are collected for each interval and combined with the MSP observations. This data is then separated using solar maximum and minimum periods. Auroral activity (oval expansions and contractions along with the frequency and number of poleward-moving auroral forms) is documented for both solar maximum and minimum periods.

  9. Approximating ambient D-region electron densities using dual-beam HF heating experiments at the high-frequency Active Auroral Research Program (HAARP)

    NASA Astrophysics Data System (ADS)

    Agrawal, Divya

    Dual-beam ELF/VLF wave generation experiments performed at the High-frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska are critically compared with the predictions of a newly developed ionospheric high frequency (HF) heating model that accounts for the simultaneous propagation and absorption of multiple HF beams. The dual-beam HF heating experiments presented herein consist of two HF beams transmitting simultaneously: one amplitude modulated (AM) HF beam modulates the conductivity of the lower ionosphere in the extremely low frequency (ELF, 30 Hz to 3 kHz) and/or very low frequency (VLF, 3 kHz to 30 kHz) band while a second HF beam broadcasts a continuous waveform (CW) signal, modifying the efficiency of ELF/VLF conductivity modulation and thereby the efficiency of ELF/VLF wave generation. Ground-based experimental observations are used together with the predictions of the theoretical model to identify the property of the received ELF/VLF wave that is most sensitive to the effects of multi-beam HF heating, and that property is determined to be the ELF/VLF signal magnitude. The dependence of the generated ELF/VLF wave magnitude on several HF transmission parameters (HF power, HF frequency, and modulation waveform) is then experimentally measured and analyzed within the context of the multi-beam HF heating model. For all cases studied, the received ELF/VLF wave magnitude as a function of transmission parameter is analyzed to identify the dependence on the ambient D-region electron density (Ne) and/or electron temperature ( Te), in turn identifying the HF transmission parameters that provide significant independent information regarding the ambient conditions of the D-region ionosphere. A theoretical analysis is performed to determine the conditions under which the effects of Ne and Te can be decoupled, and the results of this analysis are applied to identify an electron density profile that can reproduce the unusually high level of ELF

  10. Kinetic processes in the plasma sheet observed during auroral activity

    NASA Astrophysics Data System (ADS)

    Fillingim, Matthew Owen

    In this dissertation we analyze plasma sheet magnetic field and plasma data observed during varying levels of auroral activity from very small, isolated events known as pseudobreakups to large, global events known as substorms. The plasma and magnetic field data are taken from instruments onboard the WIND spacecraft while it traverses the near-Earth plasma sheet. Simultaneous global auroral images from POLAR/UVI allow us to determine the auroral activity level. The goal of this dissertation is to provide the most complete set of plasma sheet observations during auroral activity currently available. The kinetic aspects of the plasma dynamics which have largely been ingnored in other works are emphasized here. We have the capability to resolve changes in the three dimensional ion distribution functions with a time resolution comparable to or faster than the local ion gyroperiod. In addition, we consider the typically neglected electron dynamics when relating plasma sheet processes to the aurora. We find that the plasma sheet signatures of both pseudobreakups and substorms appear very similar. During both types of events, increases in auroral precipitation into the ionosphere are associated with large amplitude, high frequency magnetic field fluctuations, large Earthward ion < v>, increases in the fluxes of high energy ions and electrons, and hardening of the electron spectrum. Both ion and electron distributions appear to be composed of multiple components. Electromagnetic waves with power at frequencies up to and above the local proton gyrofrequency area also observed. Additionally, the ion distributions can change significantly in one gyroperiod. Together, these results imply that the microphysical processes occurring in the plasma sheet during pseudobreakups and substorms are the same and that kinetic effects are important. Therefore, magnetohydrodynamics (MHD) cannot adequately describe the physics occurring during large ion < v> events.

  11. On the nature of ULF wave power during nightside auroral activations and substorms: 2. Temporal evolution

    NASA Astrophysics Data System (ADS)

    Rae, I. J.; Murphy, K. R.; Watt, C. E. J.; Mann, I. R.

    2011-01-01

    We present a statistical analysis of the time evolution of ground magnetic fluctuations in three (12-48 s, 24-96 s and 48-192 s) period bands during nightside auroral activations. We use an independently derived auroral activation list composed of both substorms and pseudo-breakups to provide an estimate of the activation times of nightside aurora during periods with comprehensive ground magnetometer coverage. One hundred eighty-one events in total are studied to demonstrate the statistical nature of the time evolution of magnetic wave power during the ˜30 min surrounding auroral activations. We find that the magnetic wave power is approximately constant before an auroral activation, starts to grow up to 90 s prior to the optical onset time, maximizes a few minutes after the auroral activation, then decays slightly to a new, and higher, constant level. Importantly, magnetic ULF wave power always remains elevated after an auroral activation, whether it is a substorm or a pseudo-breakup. We subsequently divide the auroral activation list into events that formed part of ongoing auroral activity and events that had little preceding geomagnetic activity. We find that the evolution of wave power in the ˜10-200 s period band essentially behaves in the same manner through auroral onset, regardless of event type. The absolute power across ULF wave bands, however, displays a power law-like dependency throughout a 30 min period centered on auroral onset time. We also find evidence of a secondary maximum in wave power at high latitudes ˜10 min following isolated substorm activations. Most significantly, we demonstrate that magnetic wave power levels persist after auroral activations for ˜10 min, which is consistent with recent findings of wave-driven auroral precipitation during substorms. This suggests that magnetic wave power and auroral particle precipitation are intimately linked and key components of the substorm onset process.

  12. Continuous auroral activity related to high speed streams with interplaneraty ALFV&N wave trains

    NASA Technical Reports Server (NTRS)

    Guarnieri, Fernando L.; Tsurutani, Bruce T.; Gonzalez, Walter D.; Kamide, Yosuke; Zhou, Xiaoyan

    2004-01-01

    We discuss a type of intense magnetospheric/auroral activity that is not always substorms: High-Intensity, Long-Duration, Continuous AE Activity (HILDCAA) events, which occur during high speed solar wind streams. The high speed streams contain large-amplitude, nonlinear Alfvtn waves. Analyses of POLAR UV images, demonstrate that the AE increases/AL decreases in HILDCAAs are not always substorm expansion phases (although some substorms may occur). The associated auroral W energy deposition is throughout a continuous (360') auroral oval. During some image intervals, the dayside aurora is the most remarkable feature. Our hypothesis is that solar wind energy transfer from the solar wind to the magnetosphere/ionosphere is primarily directly driven due to the finite wavelength Alfv6n waves and the rapid dBz/dt variability.

  13. Field-aligned current signatures during auroral activations of Feb. 16, 0220 UT substorm

    NASA Astrophysics Data System (ADS)

    Nakamura, R.; Angelopoulos, V.; Frey, H.; Auster, U.

    2009-04-01

    Two auroral activations with poleward/equatorward expansion were observed starting around 0216 UT and 0243 UT on 16 Feb 2008, when the five THEMIS spacecraft were distributed in the premidnight to midnight (22-24 MLT) region between 8 and 18 RE downtail. We compare and contrast the possible field-aligned current signatures associated with dipolarization accompanied by Earthward flows observed at the THD(P3) and THE(P4) spacecraft in the premidnight sector at downtail distances between 8 and 9 RE by referring also to the mid-tail spacecraft, THC(P2) and THB(P1), which provide information on the current sheet configuration. Both dipolarization events started from the tailward side, THD(P3), but had quite different profiles in the magnetic shear components relevant to the field aligned current, as well as in the magnetotail current sheet configuration and auroral signatures. The 0216 UT event occurred in a thinner near-Earth current sheet condition and THD(P3) and THE(P4) detected dipolarization accompanied by fast flows and enhanced shear in the magnetic field, while conjugate ground signatures suggest development of a slant North-south aligned aurora, east of a small surge. During the 0243 UT event, X-line signatures at a midtail thin current sheet were observed, followed by a large-scale plasma sheet expansion and the associated auroral activation took place more poleward. Dipolarization was again observed at THD(P3) and THE(P4) but accompanied by less significant shear component and delay in the fast flow signatures compared to the magnetic signatures. We discuss these two different dipolarization/field aligned current signatures in terms of different stages of the fast flows interacting with the ambient field in a different configuration of the tail current sheet.

  14. Interplanetary Alfven waves and auroral (substorm) activity: IMP 8

    SciTech Connect

    Tsurutani, B.T.; Gould, T.; Goldstein, B.E. ); Gonzalez, W.D. ); Sugiura, Masahisa )

    1990-03-01

    Almost year of IMP 8 interplanetary magnetic field and plasma data (Days 1-312, 1979) have been examined to determine the interplanetary causes of geomagnetic AE activity. The nature of the interplanetary medium (Alfvenic or non-Alfvenic) and the B{sub 2} correlation with AE were examined over 12-hour increments throughout the study. It is found that Alfvenic wave intervals (defined as V{sub x}-B{sub x} cross-correlation coefficients of >0.6) are present over 60% of the time and the southward component of the Alfven waves is well correlated with AE (average peak correlation coefficient 0.62), with a median lag of 43 min. The most probable delay of AE from B{sub s} is considerably shorter, about 20-25 min. Southward magnetic fields during non-Alfvenic intervals (V{sub x}-B{sub x} cross-correlation coefficients of < 0.4) are equally effective in producing geomagnetic activity. Peak correlation coefficients and lags are similar to those of Alfvenic intervals. From this statistical study, no major differences in the magnetospheric response to Alfvenic and non-Alfvenic intervals were obvious. The high-intensity long-duration continuous AE activity (HILDCAA) events discussed previously by Tsurutani and Gonzalez (1987) are demosntrated to be caused by the southward components of the Alfven waves, presumably through the process of magnetic reconnection. The lag times of AE from B{sub s} were variable from event to event (and at different times within the Alfven wave train), ranging from 45 min to as little as 0 min. The cause of this variable delay is somewhat surprising and is not presently well understood.

  15. Variability of Mass Dependence of Auroral Acceleration Processes with Solar Activity

    NASA Technical Reports Server (NTRS)

    Ghielmetti, Arthur G.

    1997-01-01

    The objectives of this investigation are to improve understanding of the mass dependent variability of the auroral acceleration processes and so to clarify apparent discrepancies regarding the altitude and local time variations with solar cycle by investigating: (1) the global morphological relationships between auroral electric field structures and the related particle signatures under varying conditions of solar activity, and (2) the relationships between the electric field structures and particle signatures in selected events that are representative of the different conditions occurring during a solar cycle. The investigation is based in part on the Lockheed UFI data base of UpFlowing Ion (UFI) events in the 5OO eV to 16keV energy range and associated electrons in the energy range 7O eV to 24 keV. This data base was constructed from data acquired by the ion mass spectrometer on the S3-3 satellite in the altitude range of I to 1.3 Re. The launch of the POLAR spacecraft in early 1996 and successful operation of its TIMAS ion mass spectrometer has provided us with data from within the auroral acceleration regions during the current solar minimum. The perigee of POLAR is at about 1 Re, comparable to that of S3-3. The higher sensitivity and time resolution of TIMAS compared to the ion mass spectrometer on S3-3 together with its wider energy range, 15 eV to 33 keV, facilitate more detailed studies of upflowing ions.

  16. Danish auroral science history

    NASA Astrophysics Data System (ADS)

    Stauning, P.

    2011-01-01

    Danish auroral science history begins with the early auroral observations made by the Danish astronomer Tycho Brahe during the years from 1582 to 1601 preceding the Maunder minimum in solar activity. Included are also the brilliant observations made by another astronomer, Ole Rømer, from Copenhagen in 1707, as well as the early auroral observations made from Greenland by missionaries during the 18th and 19th centuries. The relations between auroras and geomagnetic variations were analysed by H. C. Ørsted, who also played a vital role in the development of Danish meteorology that came to include comprehensive auroral observations from Denmark, Iceland and Greenland as well as auroral and geomagnetic research. The very important auroral investigations made by Sophus Tromholt are outlined. His analysis from 1880 of auroral observations from Greenland prepared for the significant contributions from the Danish Meteorological Institute, DMI, (founded in 1872) to the first International Polar Year 1882/83, where an expedition headed by Adam Paulsen was sent to Greenland to conduct auroral and geomagnetic observations. Paulsen's analyses of the collected data gave many important results but also raised many new questions that gave rise to auroral expeditions to Iceland in 1899 to 1900 and to Finland in 1900 to 1901. Among the results from these expeditions were 26 unique paintings of the auroras made by the artist painter, Harald Moltke. The expedition to Finland was headed by Dan la Cour, who later as director of the DMI came to be in charge of the comprehensive international geomagnetic and auroral observations made during the Second International Polar Year in 1932/33. Finally, the article describes the important investigations made by Knud Lassen during, among others, the International Geophysical Year 1957/58 and during the International Quiet Sun Year (IQSY) in 1964/65. With his leadership the auroral and geomagnetic research at DMI reached a high international

  17. Equatorial magnetospheric particles and auroral precipitations

    NASA Astrophysics Data System (ADS)

    McIlwain, C. E.

    The injection boundary beyond which fresh hot plasma appears each magnetospheric substorm is generalized and extended to circle the Earth. The concept of an auroral shell representing the inner limit of active auroral processes is introduced. It is proposed that at low altitudes, this shell marks the equatorward edge of the auroral ovals, and that at high altitudes, it marks the injection boundary. The auroral ring is defined as the intersection of the auroral shell with the magnetic equator. A simple equation for computing the expected location of the auroral ring as a function of local time and magnetic disturbance level is obtained. Tests indicate that the model is valid and reasonably accurate.

  18. ISIS-2 satellite imagery and auroral morphology

    NASA Technical Reports Server (NTRS)

    Anger, C. D.; Murphree, J. S.

    1976-01-01

    Auroral morphology is emphasized over auroral dynamics in a paper describing conspicuous auroral features picked up by the ISIS-2 scanning photometer. Results of improved programs designed to transform the data into a corrected geomagnetic coordinate frame and generate latitude profiles of auroral intensities at different magnetic local times are reported. The diffuse aurora and its relation to the morphology of discrete aurorae is given special attention.

  19. Substorm evolution of auroral structures

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Juusola, L.; Whiter, D.; Kauristie, K.

    2015-07-01

    Auroral arcs are often associated with magnetically quiet time and substorm growth phases. We have studied the evolution of auroral structures during global and local magnetic activity to investigate the occurrence rate of auroral arcs during different levels of magnetic activity. The ground-magnetic and auroral conditions are described by the magnetometer and auroral camera data from five Magnetometers — Ionospheric radars — All-sky cameras Large Experiment stations in Finnish and Swedish Lapland. We identified substorm growth, expansion, and recovery phases from the local electrojet index (IL) in 1996-2007 and analyzed the auroral structures during the different phases. Auroral structures were also analyzed during different global magnetic activity levels, as described by the planetary Kp index. The distribution of auroral structures for all substorm phases and Kp levels is of similar shape. About one third of all detected structures are auroral arcs. This suggests that auroral arcs occur in all conditions as the main element of the aurora. The most arc-dominated substorm phases occur in the premidnight sector, while the least arc-dominated substorm phases take place in the dawn sector. Arc event lifetimes and expectation times calculated for different substorm phases show that the longest arc-dominated periods are found during growth phases, while the longest arc waiting times occur during expansion phases. Most of the arc events end when arcs evolve to more complex structures. This is true for all substorm phases. Based on the number of images of auroral arcs and the durations of substorm phases, we conclude that a randomly selected auroral arc most likely belongs to a substorm expansion phase. A small time delay, of the order of a minute, is observed between the magnetic signature of the substorm onset (i.e., the beginning of the negative bay) and the auroral breakup (i.e., the growth phase arc changing into a dynamic display). The magnetic onset was

  20. Altitude Variations of the Peak Auroral Emissions within Auroral Structures

    NASA Astrophysics Data System (ADS)

    Sangalli, L.

    2015-12-01

    The MIRACLE network monitors auroral activity in the Fennoscandian sector of Europe. Network stations cover the range of 55° to 57° magnetic latitude North and span two hours in magnetic local time. Some of the MIRACLE network stations include digital all-sky cameras (ASC) with overlapping field-of-views located at the latitude aurora occurs. The ASCs in this network operate at three different wavelengths: 427.8 nm (blue line), 557.7 nm (green line) and 630.0 nm (red line). These wavelengths are selected using narrow band filters. The new ASC systems are based on electron multiplying CCDs (emCCD), which allow higher time and spatial resolutions. The peak auroral emission altitude is determined using two ASC images from a station pair. Different auroral events are used to evaluate the altitude variations of the peak auroral emissions within auroral structures and its evolution in time.

  1. Auroral particles

    NASA Technical Reports Server (NTRS)

    Evans, David S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  2. GPS scintillation effects associated with polar cap patches and substorm auroral activity: direct comparison

    NASA Astrophysics Data System (ADS)

    Jin, Yaqi; Moen, Jøran I.; Miloch, Wojciech J.

    2014-08-01

    We directly compare the relative GPS scintillation levels associated with regions of enhanced plasma irregularities called auroral arcs, polar cap patches, and auroral blobs that frequently occur in the polar ionosphere. On January 13, 2013 from Ny-Ålesund, several polar cap patches were observed to exit the polar cap into the auroral oval, and were then termed auroral blobs. This gave us an unprecedented opportunity to compare the relative scintillation levels associated with these three phenomena. The blobs were associated with the strongest phase scintillation (σϕ), followed by patches and arcs, with σϕ up to 0.6, 0.5, and 0.1 rad, respectively. Our observations indicate that most patches in the nightside polar cap have produced significant scintillations, but not all of them. Since the blobs are formed after patches merged into auroral regions, in space weather predictions of GPS scintillations, it will be important to enable predictions of patches exiting the polar cap.

  3. High frequency active auroral research program (HAARP) imager

    NASA Astrophysics Data System (ADS)

    Lance, Cyril; Eather, Robert

    1993-09-01

    A low-light-level monochromatic imaging system was designed and fabricated which was optimized to detect and record optical emissions associated with high-power RF heating of the ionosphere. The instrument is capable of detecting very low intensities, of the order of 1 Rayleigh, from typical ionospheric atomic and molecular emissions. This is achieved through co-adding of ON images during heater pulses and subtraction of OFF (background) images between pulses. Images can be displayed and analyzed in real time and stored in optical disc for later analysis. Full image processing software is provided which was customized for this application and uses menu or mouse user interaction.

  4. The Auroral Spatial Structures Probe: magnetic and electric field measurements during an active aurora at fine spatial and temporal scales

    NASA Astrophysics Data System (ADS)

    Martineau, R. J.; Pratt, J.; Swenson, C.

    2015-12-01

    The Auroral Spatial Structures Probe was a rocket campaign that launched from Poker Flat on January 28, 2015 at 10:41:01 UTC to make multi-point vector observations of the magnetic and electric fields during an active aurora. With 6 instrumented payloads deployed from the rocket in addition to the main payload, each payload making simultaneous measurements of the magnetic and electric fields, the goals of this mission are to resolve the temporal-spatial ambiguity concerning the structures of the electric and magnetic fields during an active auroral event. The vector nature of these measurements requires an accurate knowledge of attitude throughout the flight. Each payload was equipped with gyroscopes to obtain a post-processed attitude solution after the flight. While the main payload's inertial sensors functioned well, the spin axis gyroscope on the subpayloads saturated due to a design flaw. To obtain the attitude and render the vector measurements useful, a least-squares based approach to estimate the attitude history of the payloads was devised using the magnetic and electric field measurements. Once the attitude solution was applied the temporal structures seen in the magnetic and electric fields while flying through the auroral arc are strongly correlated between payloads. We present the new attitude history estimation approach and discuss its strengths and weaknesses compared to traditional attitude methods. We also present preliminary findings from the magnetic and electric field instruments.The Auroral Spatial Structures Probe was a rocket campaign that launched from Poker Flat on January 28, 2015 at 10:41:01 UTC to make multi-point vector observations of the magnetic and electric fields during an active aurora. With 6 instrumented payloads deployed from the rocket in addition to the main payload, each payload making simultaneous measurements of the magnetic and electric fields, the goals of this mission are to resolve the temporal-spatial ambiguity

  5. Energetic auroral and polar ion outflow at DE 1 altitudes Magnitude, composition, magnetic activity dependence, and long-term variations

    NASA Technical Reports Server (NTRS)

    Yau, A. W.; Lenchyshyn, L.; Shelley, E. G.; Peterson, W. K.

    1985-01-01

    Data acquired from the Dynamics Explorer I Energetic Ion Composition Spectrometer in the period from September 1981 to May 1984 are used to determine the magnitude of the terrestrial ion outflow in the 0.01-17 keV/el range. The data are also employed to investigate the mass composition and topology (local time and invariant latitude distributions) of the ion outflow, as well as the outflow's magnetic activity dependence and long-term variation. The relative importance of auroral versus polar cap upflowing ions as a source of energetic plasma for various parts of the magnetosphere is examined.

  6. Quantifying the auroral response from measured source populations of electrons and electromagnetic wave activity

    NASA Astrophysics Data System (ADS)

    Samara, M.; Michell, R.; Grubbs, G. A., II; Davidson, R. K.; Khazanov, G. V.; Glocer, A.; Hampton, D.

    2015-12-01

    A case study is presented, where a quantitative connection is made between the measured auroral intensities and the source populations of electromagnetic waves and trapped electrons measured by THEMIS. We combine a theoretical model and high-resolution multi-spectral ground based imaging of the aurora at the THEMIS footpoint in order to interpret these data in the context of the coupled magnetosphere-ionosphere system. The THEMIS wave and particle measurements form the inputs into the Khazanov, et al., 2014 model that uses a Boltzman-Landau kinetic equation, uniformly describing the entire electron distribution function, which includes the affiliated production of secondary electrons (E < 600 eV) and their associated ionosphere-magnetosphere coupling processes. The model output will in turn be used to determine the expected auroral intensities (in Rayleighs) when considering only the primary precipitating electrons and also when both the primary and mirroring secondary electrons are included. These predicted auroral intensities will be compared to measured ones from several ground-based imagers at Poker Flat, AK, where we have high-resolution multiple emission line (557.7 nm and 427.8 nm) data at a 3.3 Hz frame rate.

  7. The MITHRAS: A program of simultaneous radar observations of the high-latitude auroral zone

    NASA Astrophysics Data System (ADS)

    Delabeaujardiere, O.; Baron, M. J.; Wickwar, V. B.; Senior, C.; Evans, J. V.

    1982-11-01

    An intensive campaign of coordinated incoherent-scatter radar experiments took place in 1981-1982. It was planned to take advantage of the short period during which three incoherent-scatter radars could probe the auroral zone simultaneously. The three incoherent-scatter radars that participated in the MITHRAS experiments were Chatanika, Millstone-Hill, and EISCAT. Collaborative studies were undertaken using data from the DE spacecraft and the stare radar. There were three main types of MITHRAS experiments, each with a different scientific purpose. MITHRAS 1 was aimed at large latitudinal coverage of F-region drifts, electron-densities and temperatures. MITHRAS 2 was designed for very good height and time resolution. MITHRAS 3 was intermediate between the other two modes. It provided both E- and F-region coverage over several degrees in latitude. Under the MITHRAS project, substantial changes and additions were made to the software and hardware systems at Millstone and Chatanika. Thirty-three MITHRAS experiments were performed. Most of the data have been reduced. The analysis and interpretation of the date are well underway.

  8. DMSP Auroral Charging at Solar Cycle 24 Maximum

    NASA Technical Reports Server (NTRS)

    Chandler, Michael; Parker, Linda Neergaard; Minow, Joseph I.

    2013-01-01

    It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions (Frooninckx and Sojka, 1992; Anderson and Koons, 1996; Anderson, 2012). These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka (1992). These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.

  9. DMSP Auroral Charging at Solar Cycle 24 Maximum

    NASA Technical Reports Server (NTRS)

    Chandler, M.; Parker, L. Neergaard; Minow, J. I.

    2013-01-01

    It has been well established that polar orbiting satellites can experience mild to severe auroral charging levels (on the order of a few hundred volts to few kilovolts negative frame potentials) during solar minimum conditions. These same studies have shown a strong reduction in charging during the rising and declining phases of the past few solar cycles with a nearly complete suppression of auroral charging at solar maximum. Recently, we have observed examples of high level charging during the recent approach to Solar Cycle 24 solar maximum conditions not unlike those reported by Frooninckx and Sojka. These observations demonstrate that spacecraft operations during solar maximum cannot be considered safe from auroral charging when solar activity is low. We present a survey of auroral charging events experienced by the Defense Meteorological Satellite Program (DMSP) F16 satellite during Solar Cycle 24 maximum conditions. We summarize the auroral energetic particle environment and the conditions necessary for charging to occur in this environment, we describe how the lower than normal solar activity levels for Solar Cycle 24 maximum conditions are conducive to charging in polar orbits, and we show examples of the more extreme charging events, sometimes exceeding 1 kV, during this time period.

  10. Wave and Particle Interactions in the High and Low-Altitude Auroral Region During Rising Solar Activity

    NASA Technical Reports Server (NTRS)

    Gurnett, Donald A.; Menietti, J. D.

    2003-01-01

    The project has resulted in four separate investigations, which are each in various stages of publication in the refereed scientific journals. The first investigation was of the generation of electrostatic electron cyclotron waves observed by the Polar spacecraft throughout the auroral regions, dayside cusp, and polar magnetosphere. We have since discovered that these waves are also present within the magnetopause and magnetosheath, which is one of the topics of a second study, entitled: 'Polar observations of plasma waves in and near the dayside magnetopause/magnetosheath.' A third study of plasma waves focussed on kilometric continuum (KC) emission. This work is reported in a paper entitled 'Near-source and Remote Observations of Kilometric Continuum Radiation From Multi-spacecraft Observations'.The final investigation of this program concerns the possible transverse heating of auroral ions by impulsive wave structures. We summarize that substantial transverse ion heating has already occurred at lower altitudes. Abstracts of the above four studies are included in the Appendix to this final report.

  11. Two substorm studies of relations between westward electric fields in the outer plasmasphere, auroral activity, and geomagnetic perturbations

    NASA Technical Reports Server (NTRS)

    Carpenter, D. L.; Akasofu, S.

    1972-01-01

    Temporal variations of the westward component of the magnetospheric convection electric field in the outer plasmasphere were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer plasmasphere increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.

  12. On the uniqueness of linear moving-average filters for the solar wind-auroral geomagnetic activity coupling

    NASA Technical Reports Server (NTRS)

    Vassiliadis, D.; Klimas, A. J.

    1995-01-01

    The relation between the solar wind input to the magetosphere, VB(sub South), and the auroral geomagnetic index AL is modeled with two linear moving-average filtering methods: linear prediction filters and a driven harmonic oscillator in the form of an electric circuit. Although the response of the three-parameter oscillator is simpler than the filter's, the methods yield similar linear timescales and values of the prediction-observation correlation and the prediction Chi(exp 2). Further the filter responses obtained by the two methods are similar in their long-term features. In these aspects the circuit model is equivalent to linear prediction filtering. This poses the question of uniqueness and proper interpretation of detailed features of the filters such as response peaks. Finally, the variation of timescales and filter responses with the AL activity level is discussed.

  13. Dependence of the high-latitude plasma irregularities on the auroral activity indices: a case study of 17 March 2015 geomagnetic storm

    NASA Astrophysics Data System (ADS)

    Cherniak, Iurii; Zakharenkova, Irina

    2015-09-01

    The magnetosphere substorm plays a crucial role in the solar wind energy dissipation into the ionosphere. We report on the intensity of the high-latitude ionospheric irregularities during one of the largest storms of the current solar cycle—the St. Patrick's Day storm of 17 March 2015. The database of more than 2500 ground-based Global Positioning System (GPS) receivers was used to estimate the irregularities occurrence and dynamics over the auroral region of the Northern Hemisphere. We analyze the dependence of the GPS-detected ionospheric irregularities on the auroral activity. The development and intensity of the high-latitude irregularities during this geomagnetic storm reveal a high correlation with the auroral hemispheric power and auroral electrojet indices (0.84 and 0.79, respectively). Besides the ionospheric irregularities caused by particle precipitation inside the polar cap region, evidences of other irregularities related to the storm enhanced density (SED), formed at mid-latitudes and its further transportation in the form of tongue of ionization (TOI) towards and across the polar cap, are presented. We highlight the importance accounting contribution of ionospheric irregularities not directly related with particle precipitation in overall irregularities distribution and intensity.

  14. Weak auroral emissions and particle precipitations in the dusk auroral oval

    SciTech Connect

    Ono, T.; Hirasawa, T. ); Ching-I. Meng )

    1989-09-01

    Faint auroral displays in the low-latitude region of the duskside auroral oval were examined by using 5577 A, 6300 A, and 4861 A auroral images from three monochromatic all-sky television cameras at Syowa Station, Antarctica, and simultaneous precipitating auroral particle data obtained by the U.S. Air Force/Defense Meteorological Satellite Program (USAF/DMSP) F6 satellite. In the low-latitude region of the duskside auroral oval, we found three types of auroral displays with weak optical intensity: (1) proton auroras, (2) pulsating auroras, and (3) faint discrete auroral arcs distinct only in the 6300 A emission. In usual cases, the energy input into this region is mostly carried y proton precipitations to produce proton auroras mainly at wavelengths of 4861 A and 5577 A. Pulsating features are sometimes observed in the diffuse auroral region in the dusk sector. Comparing auroral images with the nearly simultaneous data of precipitating auroral particles, we confirmed that the pulsating auroras are associated with the intensification of precipitating electron flux from the central plasma sheet. Furthermore, electrons are the main contributors to the energy input into the duskside auroral oval in this case. We also found that discrete auroras sometimes appeared in the 6300 A images, but not in images at other wavelengths. They appear in the equatorial part of the dusk auroral oval. These 6300 A discrete auroras correspond to weak precipitation spikes of low-energy electrons simultaneously measured by DMSP satellites. The flux and average energy of these electron spikes are about 10{sup 8}/(cm{sup 2} sr s) and 100 eV, respectively. They are intense enough to excite 6300 A emissions but not 5577 A emissions, as detected from the ground observations. {copyright} American Geophysical Union 1989

  15. Observations of auroral fading before breakup

    NASA Technical Reports Server (NTRS)

    Pellinen, R. J.; Heikkila, W. J.

    1978-01-01

    The onset of auroral breakup was studied by using a variety of instruments with time resolution of some tens of second. Rapid sequences of all-sky photographs, and fast meridian scans by photometers, show that breakup is usually preceded by moderate brightening, followed by fading of the auroral brightness lasting one or two minutes, before the actual breakup itself. This optical activity is closely correlated with the development of auroral radar echoes. Data from a magnetometer network provide some indication of a correlated response by the local auroral and ionospheric currents. Riometer recordings show a slow decrease in ionspheric radio wave absorption over a period of about ten minutes prior to breakup, with the largest decrease essentially to quiet-time values in the region of auroral fading and subsequent breakup.

  16. Trigger, an active release experiment that stimulated auroral particle precipitation and wave emissions

    NASA Technical Reports Server (NTRS)

    Holmgren, G.; Bostroem, R.; Kelley, M. C.; Kintner, P. M.; Lundin, R.; Fahleson, U. V.; Bering, E. A.; Sheldon, W. R.

    1979-01-01

    The experiment design, including a description of the diagnostic and chemical release payload, and the general results are given for an auroral process simulation experiment. A drastic increase of the field aligned charged particle flux was observed over the approximate energy range 10 eV to more than 300 keV, starting about 150 ms after the release and lasting about one second. The is evidence of a second particle burst, starting one second after the release and lasting for tens of seconds, and evidence for a periodic train of particle bursts occurring with a 7.7 second period from 40 to 130 seconds after the release. A transient electric field pulse of 200 mv/m appeared just before the particle flux increase started. Electrostatic wave emissions around 2 kHz, as well as a delayed perturbation of the E-region below the plasma cloud were also observed. Some of the particle observations are interpreted in terms of field aligned electrostatic acceleration a few hundred kilometers above the injected plasma cloud. It is suggested that the acceleration electric field was created by an instability driven by field aligned currents originating in the plasma cloud.

  17. Statistical analysis of extreme auroral electrojet indices

    NASA Astrophysics Data System (ADS)

    Nakamura, Masao; Yoneda, Asato; Oda, Mitsunobu; Tsubouchi, Ken

    2015-09-01

    Extreme auroral electrojet activities can damage electrical power grids due to large induced currents in the Earth, degrade radio communications and navigation systems due to the ionospheric disturbances and cause polar-orbiting satellite anomalies due to the enhanced auroral electron precipitation. Statistical estimation of extreme auroral electrojet activities is an important factor in space weather research. For this estimation, we utilize extreme value theory (EVT), which focuses on the statistical behavior in the tail of a distribution. As a measure of auroral electrojet activities, auroral electrojet indices AL, AU, and AE, are used, which describe the maximum current strength of the westward and eastward auroral electrojets and the sum of the two oppositely directed in the auroral latitude ionosphere, respectively. We provide statistical evidence for finite upper limits to AL and AU and estimate the annual expected number and probable intensity of their extreme events. We detect two different types of extreme AE events; therefore, application of the appropriate EVT analysis to AE is difficult.

  18. Characterization and diagnostic methods for geomagnetic auroral infrasound waves

    NASA Astrophysics Data System (ADS)

    Oldham, Justin J.

    Infrasonic perturbations resulting from auroral activity have been observed since the 1950's. In the last decade advances in infrasonic microphone sensitivity, high latitude sensor coverage, time series analysis methods and computational efficiency have elucidated new types of auroral infrasound. Persistent periods of infrasonic activity associated with geomagnetic sub-storms have been termed geomagnetic auroral infrasound waves [GAIW]. We consider 63 GAIW events recorded by the Fairbanks, AK infrasonic array I53US ranging from 2003 to 2014 and encompassing a complete solar cycle. We make observations of the acoustic features of these events alongside magnetometer, riometer, and all-sky camera data in an effort to quantify the ionospheric conditions suitable for infrasound generation. We find that, on average, the generation mechanism for GAIW is confined to a region centered about ~60 0 longitude east of the anti-Sun-Earth line and at ~770 North latitude. We note furthermore that in all cases considered wherein imaging riometer data are available, that dynamic regions of heightened ionospheric conductivity periodically cross the overhead zenith. Consistent features in concurrent magnetometer conditions are also noted, with irregular oscillations in the horizontal component of the field ubiquitous in all cases. In an effort to produce ionosphere based infrasound free from the clutter and unknowns typical of geophysical observations, an experiment was undertaken at the High Frequency Active Auroral Research Program [HAARP] facility in 2012. Infrasonic signals appearing to originate from a source region overhead were observed briefly on 9 August 2012. The signals were observed during a period when an electrojet current was presumed to have passed overhead and while the facilities radio transmitter was periodically heating the lower ionosphere. Our results suggest dynamic auroral electrojet currents as primary sources of much of the observed infrasound, with

  19. Auroral fragmentation into patches

    NASA Astrophysics Data System (ADS)

    Shiokawa, Kazuo; Hashimoto, Ayumi; Hori, Tomoaki; Sakaguchi, Kaori; Ogawa, Yasunobu; Donovan, Eric; Spanswick, Emma; Connors, Martin; Otsuka, Yuichi; Oyama, Shin-Ichiro; Nozawa, Satonori; McWilliams, Kathryn

    2014-10-01

    Auroral patches in diffuse auroras are very common features in the postmidnight local time. However, the processes that produce auroral patches are not yet well understood. In this paper we present two examples of auroral fragmentation which is the process by which uniform aurora is broken into several fragments to form auroral patches. These examples were observed at Athabasca, Canada (geomagnetic latitude: 61.7°N), and Tromsø, Norway (67.1°N). Captured in sequences of images, the auroral fragmentation occurs as finger-like structures developing latitudinally with horizontal-scale sizes of 40-100 km at ionospheric altitudes. The structures tend to develop in a north-south direction with speeds of 150-420 m/s without any shearing motion, suggesting that pressure-driven instability in the balance between the earthward magnetic-tension force and the tailward pressure gradient force in the magnetosphere is the main driving force of the auroral fragmentation. Therefore, these observations indicate that auroral fragmentation associated with pressure-driven instability is a process that creates auroral patches. The observed slow eastward drift of aurora during the auroral fragmentation suggests that fragmentation occurs in low-energy ambient plasma.

  20. Characteristics of solar wind control on Jovian UV auroral activity deciphered by long-term Hisaki EXCEED observations: Evidence of preconditioning of the magnetosphere?

    NASA Astrophysics Data System (ADS)

    Kita, Hajime; Kimura, Tomoki; Tao, Chihiro; Tsuchiya, Fuminori; Misawa, Hiroaki; Sakanoi, Takeshi; Kasaba, Yasumasa; Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Yoshikawa, Ichiro; Fujimoto, Masaki

    2016-07-01

    While the Jovian magnetosphere is known to have the internal source for its activity, it is reported to be under the influence of the solar wind as well. Here we report the statistical relationship between the total power of the Jovian ultraviolet aurora and the solar wind properties found from long-term monitoring by the spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board the Hisaki satellite. Superposed epoch analysis indicates that auroral total power increases when an enhanced solar wind dynamic pressure hits the magnetosphere. Furthermore, the auroral total power shows a positive correlation with the duration of a quiescent interval of the solar wind that is present before a rise in the dynamic pressure, more than with the amplitude of dynamic pressure increase. These statistical characteristics define the next step to unveil the physical mechanism of the solar wind control on the Jovian magnetospheric dynamics.

  1. The enigma of auroral spirals

    NASA Astrophysics Data System (ADS)

    Haerendel, G.

    One of the most spectacular forms that the aurora borealis can assume is the large-scale spiral Spirals are dominantly observed along the poleward boundary of the auroral oval during active periods Two concepts have been pursued in explaining their origin and in particular the counterclockwise sense of rotation of the luminous structures when viewed along the magnetic field direction An essentially magnetostatic theory following Hallinan 1976 attributes the spiral pattern to the twisting of field-lines caused by a centrally located upward field-aligned current According to Oguti 1981 and followers a clockwise rotation of the plasma flow produces the anticlockwise structure There are observations seemingly confirming or contradicting either theory In this paper it is argued that both concepts are insufficient in that only parts of the underlying physics are considered Besides field-aligned currents and plasma flow one has to take into at least two further aspects The ionospheric conductivity modified by particle precipitation has an impact on the magnetospheric plasma dynamics Furthermore auroral arcs are not fixed entities subject to distortions by plasma flows or twisted field-lines but sites of transient releases of energy We suggest that auroral spirals are ports of entry or exit of plasma into or out of the auroral oval This way it can be understood why a clockwise plasma flow can create an anticlockwise luminous pattern

  2. Integral probability of auroral electron flux events from SSJ/4 DMSP F9 electron measurements. Interim report

    SciTech Connect

    Hardy, D.A.; Bounar, K.H.

    1992-05-18

    A study has been completed to determine the probability of observing different levels of auroral electron precipitation both within fixed spatial elements in magnetic local time and corrected geomagnetic latitude, and within spatial elements when the magnetic local time is fixed but the latitude range can be varied. The auroral electron precipitation probability is defined for a series of thresholds in electron average energy and electron energy flux as a function of geomagnetic activity. The study provides the capability to determine the probability of observation of an auroral electron precipitation event for any specified threshold in average energy, energy flux, and level of geomagnetic activity for any location in the auroral region or for any line of sight through the auroral region. The input for the study is one year of data from the SSJ/4 electron and proton spectrometer flown on the F9 satellite of the Defense Meteorological Satellite Program (DMSP) comprising approximately 10, 141 hemispheric passes through the auroral region. The binning technique used to determine these probabilities is presented and some results are discussed. The operation of the software package to display the probability results is described. Defense Meteorological Satellite Program (DMSP), Aurora, Precipitating electrons, Geomagnetic Kp index, Integral probability.

  3. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily M.; Parker, Linda Neergard

    2014-01-01

    The highest level spacecraft charging observed in low Earth orbit (LEO) occurs when spacecraft are exposed to energetic auroral electrons. Since auroral charging has been identified as a mechanism responsible for on-orbit anomalies and even possible satellite failures it is important to consider extreme auroral charging events as design and test environments for spacecraft to be used in high inclination LEO orbits. This paper will report on studies of extreme auroral charging events using data from the SSJ/4 and SSJ/5 precipitating electron and ion sensors on the Defense Meteorology Satellite Program (DMSP) satellites. Early studies of DMSP charging to negative potentials =100 V focused on statistics of the electron environment responsible for charging. Later statistical studies of auroral charging have generally focused on solar cycle dependence of charging behavior and magnitude of the maximum potential and duration of the charging events. We extend these studies to focus on more detailed investigations of extreme charging event characteristics that are required to evaluate potential threats to spacecraft systems. A collection of example auroral charging events is assembled from the DMSP data set using the criteria that "extreme auroral charging" is defined as periods with spacecraft negative potentials =400 V. Specific characteristics to be treated include (but are not limited to) maximum and mean potentials, time history of spacecraft potentials through the events, total charging duration and the time potentials exceed voltage thresholds, frame charging/discharging rates, and information on geographic and geomagnetic latitudes at which the events are observed. Finally, we will comment on the implications of these studies for potential auroral charging risks to the International Space Station.

  4. Temporal and spatial evolution of discrete auroral arcs as seen by Cluster

    NASA Astrophysics Data System (ADS)

    Figueiredo, S.; Marklund, G. T.; Karlsson, T.; Johansson, T.; Ebihara, Y.; Ejiri, M.; Ivchenko, N.; Lindqvist, P.-A.; Nilsson, H.; Fazakerley, A.

    2005-10-01

    Two event studies are presented in this paper where intense convergent electric fields, with mapped intensities up to 1350 mV/m, are measured in the auroral upward current region by the Cluster spacecraft, at altitudes between 3 and 5 Earth radii. Both events are from May 2003, Southern Hemisphere, with equatorward crossings by the Cluster spacecraft of the pre-midnight auroral oval.

    Event 1 occurs during the end of the recovery phase of a strong substorm. A system of auroral arcs associated with convergent electric field structures, with a maximum perpendicular potential drop of about ~10 kV, and upflowing field-aligned currents with densities of 3 µA/m2 (mapped to the ionosphere), was detected at the boundary between the Plasma Sheet Boundary Layer (PSBL) and the Plasma Sheet (PS). The auroral arc structures evolve in shape and in magnitude on a timescale of tens of minutes, merging, broadening and intensifying, until finally fading away after about 50 min. Throughout this time, both the PS region and the auroral arc structure in its poleward part remain relatively fixed in space, reflecting the rather quiet auroral conditions during the end of the substorm. The auroral upward acceleration region is shown for this event to extend beyond 3.9 Earth radii altitude.

    Event 2 occurs during a more active period associated with the expansion phase of a moderate substorm. Images from the Defense Meteorological Satellite Program (DMSP) F13 spacecraft show that the Cluster spacecraft crossed the horn region of a surge-type aurora. Conjugated with the Cluster spacecraft crossing above the surge horn, the South Pole All Sky Imager recorded the motion and the temporal evolution of an east-west aligned auroral arc, 30 to 50 km wide. Intense electric field variations are measured by the Cluster spacecraft when crossing above the auroral arc structure, collocated with the density gradient at the PS poleward boundary

  5. Auroral spirals at Saturn

    NASA Astrophysics Data System (ADS)

    Radioti, A.; Grodent, D.; Gérard, J.-C.; Roussos, E.; Mitchell, D.; Bonfond, B.; Pryor, W.

    2015-10-01

    We report observations of auroral spirals at Saturn propagating from midnight to noon via dawn, based on Cassini/UVIS measurements. The aurora during that sequence is observed for the first time to consist of detached features swirling as they propagate from dawn to early afternoon. The features have a diameter of ˜6000 km in the ionosphere, which would correspond to 12 to 15 RS wide plasma regions in the magnetosphere. Simultaneous ENA enhancements are observed; however, they do not show a clear spiral form. We estimate the velocity of the UV auroral features to decrease from 85% of rigid corotation (28°/h) near the equatorward edge to 68% of rigid corotation (22°/h) in the poleward edge. We discuss two possible scenarios which could explain the generation of the auroral spirals. First, we suggest that the auroral spirals could be related to large dynamic hot populations which create regions with strong velocity gradients. Alternatively, a less possible theory could be that the auroral spirals are related to field line deformation from the magnetosphere to the ionosphere, similar to the scenario proposed to explain auroral spirals at Earth. Such field line twist can happen for a configuration where the magnetospheric source region is located between a pair of plasma flow vortices.

  6. Conjugacy of daytime ELF-VLF emission activities in the auroral zones

    SciTech Connect

    Sato, Natsuo ); Suzuki, Hiroyuki; Maezawa, Kiyoshi ); Saemundsson, T. )

    1990-06-01

    Statistical characteristics of emission occurrence are examined, using 1 year of digital data of 750-Hz, 2-kHz, and 4-kHz intensity records. These waves were measured simultaneously at a conjugate pair of stations, namely Syowa Station in Antarctica and Husafell in Iceland. The following notable diurnal and seasonal variation and Kp dependence was found for the daytime emissions (04-14 MLT): (1) The 750-Hz emissions were mostly observed during the daytime around noon in both conjugate regions. The emission occurrence reached a maximum 1-3 hours earlier at Syowa than at Husafell during the equinox season. The seasonal variation of 750-Hz emission occurrence showed a maximum during local summer and a minimum during local winter at both stations. The ratio of the emission enhancement in summer to that at the equinox is higher at Husafell than at Syowa. The emissions mostly occurred during moderately disturbed conditions of Kp {approximately} 2-4 at both stations. (2) The 2-kHz emission occurrence reached a maximum around 13 MLT at Syowa and around 11 MLT at Husafell. Peaks of the emission occurrence during summer shifted to the afternoonside at Syowa and to the morningside at Husafell. The occurrences at Syowa reached a maximum during local summer and a minimum during winter. (3) The occurrence of 4-kHz emissions was much more frequent at Husafell than at Syowa. The emissions at Husafell occurred mostly in the morning ({approximately}08 MLT) and in local winter, and the occurrences became more frequent with increasing magnetic activity. On the bases of these statistical characteristics, the authors discuss the effects of sunlight and geomagnetic activity which cause an asymmetry of wave propagation from the magnetosphere to the ionosphere in the two hemispheres.

  7. Auroral activities observed by SNPP VIIRS day/night band during a long period geomagnetic storm event on April 29-30, 2014

    NASA Astrophysics Data System (ADS)

    Shao, Xi; Cao, Changyong; Liu, Tung-chang; Zhang, Bin; Wang, Wenhui; Fung, Shing F.

    2015-10-01

    The Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) onboard Suomi-NPP represents a major advancement in night time imaging capabilities. The DNB senses radiance that can span 7 orders of magnitude in one panchromatic (0.5-0.9 μm) reflective solar band and provides imagery of clouds and other Earth features over illumination levels ranging from full sunlight to quarter moon. When the satellite passes through the day-night terminator, the DNB sensor is affected by stray light due to solar illumination on the instrument. With the implementation of stray light correction, stray light-corrected DNB images enable the observation of aurora occurred in the high latitude regions during geomagnetic storms. In this paper, DNB observations of auroral activities are analyzed during a long period (> 20 hours) of geomagnetic storm event occurred on Apr. 29-30, 2014. The storm event has the Bz component of interplanetary magnetic field (IMF) pointing southward for more than 20 hours. During this event, the geomagnetic storm index Dst reached -67 nT and the geomagnetic auroral electrojet (AE) index increased and reached as high as 1200 nT with large amplitude fluctuations. The event occurred during new moon period and DNB observation has minimum moon light contamination. During this event, auroras are observed by DNB for each orbital pass on the night side (~local time 1:30am) in the southern hemisphere. DNB radiance data are processed to identify regions of aurora during each orbital pass. The evolution of aurora is characterized with time series of the poleward and equatorward boundary of aurora, area, peak radiance and total light emission of the aurora in DNB observation. These characteristic parameters are correlated with solar wind and geomagnetic index parameters. It is found that the evolution of total area-integrated radiance of auroral region over the southern hemisphere correlated well with the ground geomagnetic AE index with correlation

  8. AURIO: A proposal for flying auroral imaging observatory on the Polar Platform in the Space Station/Columbus program

    NASA Astrophysics Data System (ADS)

    Stadsnes, J.; Aarsnes, K.; Anger, C. D.; Bjordal, J.; Brekke, A.; Bryant, D.; Broenstad, K.; Carter, J.; Chaloner, C.; Cogger, L. L.

    1987-08-01

    It is proposed to fly high resolution auroral imaging instruments and particle spectrometers on the Columbus Polar Platform (PPF). A set of UV and X-ray imagers with wide field of view (horizon to horizon) will map the large scale (semiglobal) features of the aurora at day and night with fairly high spatial and temporal resolution. A set of visible and X-ray imagers and imaging spectrographs in visible and UV range with narrow field (NF) of view will give images with very high spatial resolution (better than 1 km and a few km respectively for optical and X-ray imagers) and a time resolution of 1 sec. The NF-imagers will be mounted on a pointable instrument pedestal to be operated in different modes. Particle spectrometers will cover electrons and ions over a wide energy range, and with high time resolution (10 ms). It is also desireable to fly a magnetometer. The particle and field instruments should be integrated in a separate package mounted on a boom protruding at least 10 m from the PPF, to minimize the contamination from the PPF environment.

  9. Origins of the Earth's Diffuse Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Ni, Binbin; Thorne, Richard M.; Zhang, Xiaojia; Bortnik, Jacob; Pu, Zuyin; Xie, Lun; Hu, Ze-jun; Han, Desheng; Shi, Run; Zhou, Chen; Gu, Xudong

    2016-04-01

    The Earth's diffuse auroral precipitation provides the major source of energy input into the nightside upper atmosphere and acts as an essential linkage of the magnetosphere-ionosphere coupling. Resonant wave-particle interactions play a dominant role in the scattering of injected plasma sheet electrons, leading to the diffuse auroral precipitation. We review the recent advances in understanding the origin of the diffuse aurora and in quantifying the exact roles of various magnetospheric waves in producing the global distribution of diffuse auroral precipitation and its variability with the geomagnetic activity. Combined scattering by upper-and lower-band chorus accounts for the most intense inner magnetospheric electron diffuse auroral precipitation on the nightside. Dayside chorus can be responsible for the weaker dayside electron diffuse auroral precipitation. Pulsating auroras, the dynamic auroral structures embedded in the diffuse aurora, can be mainly caused by modulation of the excitation of lower band chorus due to macroscopic density variations in the magnetosphere. Electrostatic electron cyclotron harmonic waves are an important or even dominant cause for the nightside electron diffuse auroral precipitation beyond {˜}8Re and can also contribute to the occurrence of the pulsating aurora at high L-shells. Scattering by electromagnetic ion cyclotron waves could quite possibly be the leading candidate responsible for the ion precipitation (especially the reversed-type events of the energy-latitude dispersion) in the regions of the central plasma sheet and ring current. We conclude the review with a summary of current understanding, outstanding questions, and a number of suggestions for future research.

  10. Anisotropy of the Taylor scale and the correlation scale in plasma sheet magnetic field fluctuations as a function of auroral electrojet activity

    NASA Astrophysics Data System (ADS)

    Weygand, James M.; Matthaeus, W. H.; El-Alaoui, M.; Dasso, S.; Kivelson, M. G.

    2010-12-01

    Magnetic field data from the Cluster spacecraft in the magnetospheric plasma sheet are employed to determine the correlation scale and the magnetic Taylor microscale from simultaneous multiple-point measurements for multiple intervals over a range of mean magnetic field directions for three different levels of geomagnetic activity. We have determined that in the plasma sheet the correlation scale along the mean magnetic field direction decreases from 19,500 ± 2200 to 13,100 ± 700 km as the auroral electrojet activity increases from quiet (<80 nT) to active conditions (>200 nT). The reverse occurs for the correlation scale perpendicular to the magnetic field, which increases from 8200 ± 600 km to 13,000 ± 2100 km as the auroral electrojet activity increases from quiet to active conditions. This variation of the correlation scale with geomagnetic activity may mean either a change in the scale size of the turbulence driver or may mean a change in the predominance of one over another type of turbulence driving mechanism. Unlike the correlation scale, the Taylor scale does not show any clear variation with geomagnetic activity. We find that the Taylor scale is longer parallel to the magnetic field than perpendicular to it for all levels of geomagnetic activity. The correlation and Taylor scales may be used to estimate the effective magnetic Reynolds numbers separately for each angular channel. Reynolds numbers were found to be approximately independent of the angle relative to the mean magnetic field. These results may be useful in magnetohydrodynamic modeling of the magnetosphere and can contribute to our understanding of energetic particle diffusion in the magnetosphere.

  11. Revisiting geomagnetic activity at auroral latitudes: No need for regular quiet curve removal for geomagnetic activity indices based on hourly data

    NASA Astrophysics Data System (ADS)

    Martini, Daniel; Argese, Chiara; Di Loreto, Massimo; Mursula, Kalevi

    2016-07-01

    The main objective of our study is to determine if the regular quiet daily curve (QDC) subtraction is a necessary procedure in quantifying the irregular geomagnetic variations at auroral latitudes. We define the hourly ΔH index, the absolute hour-to-hour deviation in nanotesla of the hourly geomagnetic horizontal component, which assigns each sample to sample deviation as geomagnetic activity without separating the "regular" and "irregular" parts of the daily magnetic field evolution. We demonstrate that the hourly gradient of the regular Sq variation is very small with respect to the irregular part, and a bulk of the nominal daily variation is actually part of the variation driven by solar wind and interplanetary magnetic field and traditionally classified as irregular. Therefore, attempts to subtract QDC can lead to a larger error, often caused by residual deviations between the used different mathematical and methodological tools and corresponding presumptions themselves. We show that ΔH provides the best and most consistent results at most timescales with the highest effective resolution among the studied indices. We also demonstrate that the ΔH index may equally be useful as a quick-look near-real-time index of space weather and as a long-term index derived from hourly magnetometer data for space climate studies.

  12. Investigations of the auroral luminosity distribution and the dynamics of discrete auroral forms in a historical retrospective

    NASA Astrophysics Data System (ADS)

    Feldstein, Y. I.; Vorobjev, V. G.; Zverev, V. L.; Förster, M.

    2014-05-01

    conceptions about the succession of discrete auroral forms and their dynamics during disturbance intervals. This ranges from Birkeland's polar elementary storms, over the prospect of a fixed auroral pattern up to the auroral substorm model. The classic schemes of the spatial distribution and motion of discrete auroral forms during single substorms are shown in Fig. 20 (expansive and recovery phases) and Fig. 21 (creation, expansive and recovery phases). In this review we discuss various models of bulge formation, in particular as a result of new formation of arcs about 50-100 km poleward of previously existing auroral structures (Fig. 24). Discrete steps in the development of an expanding bulge are separated by 1-3 min from each other. The model of successive activations confines only to a ~40° longitudinal portion of the magnetotail (Fig. 28). We consider differences in the development of single substorms and substorms during magnetic storms. The structure and dynamics of auroras during steady magnetospheric convection (SMC) periods are dealt with in Sect. 8. A generalised scheme of the auroral distribution during SMC periods is shown in Fig. 34. Separate sections describe discrete auroras in the polar cap (Sect. 5), and the diffuse luminosity equatorward of the auroral oval (Sect. 9). Visual observations of diffuse auroral forms at midlatitudes suggest that the whole latitudinal interval between the auroral oval and the stable auroral red (SAR) arc is filled up with diffuse luminosity. SAR arcs with intensities of several tens of Rayleigh enclose systematically the region of diffuse luminosity; they are positioned at the border of the plasmasphere.

  13. Experimental studies of auroral arc generators

    SciTech Connect

    Suszcynsky, D.M.; Borovsky, J.E.; Thomsen, M.F.

    1997-08-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). An all-sky video camera system was deployed in Eagle, Alaska at the foot of the magnetic field line that threads geosynchronous satellite 1989-046 as part of a campaign to study correlations of ground-based auroral activity with satellite-based plasma and energetic particle measurements. The overall intent of the project was to study magnetosphere-ionosphere coupling as it relates to the aurora, and, in particular, to look for signatures that may help to identify various auroral generator mechanism(s). During this study, our efforts were primarily directed towards identifying the generator mechanism(s) for pulsating aurora. Our data, though not conclusive, are found to support theories that propose a cyclotron resonance mechanism for the generation of auroral pulsations.

  14. Observations of a gradual transition between Ps 6 activity with auroral torches and surgelike pulsations during strong geomagnetic disturbances

    NASA Technical Reports Server (NTRS)

    Steen, A.; Collis, P. N.; Evans, D.; Kremser, G.; Capelle, S.; Rees, D.; Tsurutani, B. T.

    1988-01-01

    This paper describes a long-lasting large-amplitude pulsation event, which occurred on January 10, 1983 in the ionosphere and magnetosphere and was characterized by Steen and Rees (1983). Over the 4-h period (0200-0600 UT), the characteristics of the pulsations in the ionosphere changed from being Ps 6 auroral torches toward substorms and back to Ps 6. At GEO, the corresponding characteristics were a modulation of the high-energy particle intensity and plasma dropouts. Based on the ideas presented by Rostoker and Samson (1984), an interpretation of the event is offered, according to which the pulsations are caused by the Kelvin-Helmholtz instability during an interval of strong magnetospheric convection. On the basis of this explanation, a new interpretation of the substorm time sequence is proposed.

  15. Theoretical and experimental studies relevant to interpretation of auroral emissions

    NASA Technical Reports Server (NTRS)

    Keffer, Charles E.

    1994-01-01

    This report describes the accomplishments of a program designed to develop the tools necessary to interpret auroral emissions measured from a space-based platform. The research was divided into two major areas. The first area was a laboratory study designed to improve our understanding of the space vehicle external environment and how it will affect the space-based measurement of auroral emissions. Facilities have been setup and measurements taken to simulate the gas phase environment around a space vehicle; the radiation environment encountered by an orbiting vehicle that passes through the Earth's radiation belts; and the thermal environment of a vehicle in Earth orbit. The second major area of study was a modeling program to develop the capability of using auroral images at various wavelengths to infer the total energy influx and characteristic energy of the incident auroral particles. An ab initio auroral calculation has been added to the extant ionospheric/thermospheric global modeling capabilities within our group. Once the addition of the code was complete, the combined model was used to compare the relative intensities and behavior of various emission sources (dayglow, aurora, etc.). Attached papers included are: 'Laboratory Facility for Simulation of Vehicle-Environment Interactions'; 'Workshop on the Induced Environment of Space Station Freedom'; 'Radiation Damage Effects in Far Ultraviolet Filters and Substrates'; 'Radiation Damage Effects in Far Ultraviolet Filters, Thin Films, and Substrates'; 'Use of FUV Auroral Emissions as Diagnostic Indicators'; and 'Determination of Ionospheric Conductivities from FUV Auroral Emissions'.

  16. Correlation Between Low Frequency Auroral Kilometric Radiation (AKR) and Auroral Structures

    NASA Technical Reports Server (NTRS)

    Paxamickas, Katherine A.; Green, James L.; Gallagher, Dennis L.; Boardsen, Scott; Mende, Stephen; Frey, Harald; Reinisch, Bodo W.

    2005-01-01

    Auroral Kilometric Radiation (AKR) is a radio wave emission that has long been associated with auroral activity. AKR is normally observed in the frequency range from -60 - 600 kHz. Low frequency AKR (or LF-AKR) events are characterized as a rapid extension of AKR related emissions to 30 kHz or lower in frequency for typically much less than 10 minutes. LF-AKR emissions predominantly occur within a frequency range of 20 kHz - 30 kHz, but there are LF-AKR related emissions that reach to a frequency of 5 kHz. This study correlates all instances of LF-AKR events during the first four years of observations from the IMAGE spacecraft's Radio Plasma Imager (WI) instrument with auroral observations from the wideband imaging camera (WIC) onboard IMAGE. The correlation between LF-AKR occurrence and WIC auroral observations shows that in the 295 confirmed cases of LF-AKR emissions, bifurcation of the aurora is seen in 74% of the cases. The bifurcation is seen in the dusk and midnight sectors of the auroral oval, where AKR is believed to be generated. The polarization of these LF-AKR emissions has yet to be identified. Although LF-AKR may not be the only phenomena correlated with bifurcated auroral structures, bifurcation will occur in most instances when LF-AKR is observed. The LF-AKR emissions may be an indicator of specific auroral processes sometimes occurring during storm-time conditions in which field-aligned density cavities extend a distance of perhaps 5-6 RE tailward from the Earth for a period of 10 minutes or less.

  17. Investigating the auroral electrojets using Swarm

    NASA Astrophysics Data System (ADS)

    Smith, Ashley; Macmillan, Susan; Beggan, Ciaran; Whaler, Kathy

    2016-04-01

    The auroral electrojets are large horizontal currents that flow within the ionosphere in ovals around the polar regions. They are an important aspect of space weather and their position and intensity vary with solar wind conditions and geomagnetic activity. The electrojet positions are also governed by the Earth's main magnetic field. During more active periods, the auroral electrojets typically move equatorward and become more intense. This causes a range of effects on Earth and in space, including geomagnetically induced currents in power transmission networks, disturbance to radio communications and increased drag on satellites due to expansion of the atmosphere. They are also indicative of where the aurora are visible. Monitoring of the auroral electrojets in the pre-satellite era was limited to the network of ground-based magnetic observatories, from which the traditional AE activity indices are produced. These suffer in particular from the stations' poor distribution in position and so this motivates the use of satellite-based measurements. With polar low-Earth orbit satellites carrying magnetometers, all latitudes can be sampled with excellent resolution. This poster presents an investigation using Swarm's magnetometer data to detect the electrojets as the spacecraft move above them. We compare and contrast two approaches, one which uses vector data and the other which uses scalar data (Hamilton and Macmillan 2013, Vennerstrom and Moretto, 2013). Using ideas from both approaches we determine the oval positions and intensities from Swarm and earlier satellites. The variation in latitude and intensity with solar wind conditions, geomagnetic activity and secular variation of the main field is investigated. We aim to elucidate the relative importance of these factors. Hamilton, B. and Macmillan, S., 2013. Investigation of decadal scale changes in the auroral oval positions using Magsat and CHAMP data. Poster at IAGA 12th Scientific Assembly, 2013. http

  18. Early auroral observations

    NASA Astrophysics Data System (ADS)

    Silverman, S.

    1998-06-01

    Early auroral observations from Europe and Asia, and catalogs of these observations, are described and discussed. Cautions to be aware of when using these data include the dating of the observation, and the cultural context, especially for observations included in histories and annals as omens and portents. Specific attention is then paid to observations from classical Greece and Rome, the Middle East in biblical times, Asian annals, and the period from late antiquity through the medieval period.

  19. Significance, Present Status and Perspectives of the Auroral Zone Magnetic Activity Monitoring by the Russian Arctic Magnetometer Network

    NASA Astrophysics Data System (ADS)

    Troshichev, O. A.; Janzhura, A. S.; Takahashi, K.

    2010-12-01

    The Roshydromet magnetometer network in Russian Arctica includes the following stations: Amderma, Dickson, Cape Chelyuskin, Tiksi, Pevek, Lovozero, Heiss Island, Vieze Island, Izvestia Island. Vitality of the first 5 of them, providing the data for derivation AE/AL/AU indices, was supported during the previous years by the International project Rapidmag (Russian Auroral and Polar Ionospheric Disturbance Magnetometers). In last two years the Roshydromet network in Arctica was subjected to reconstruction. Renovation includes construction of new polar station buildings, deployment of the satellite communication system at stations, and arrangement of new acquisition system for magnetometers. The reconstruction should ensure on-line transmission of the current magnetic data from the Arctic network to AARI and analysis of these data in the near-real time. The present state of affairs and further perspectives are discussed. Examples are given, which show that run of the AL and AU indices, derived with allowance of data from Russian Arctic stations and without this information, can be principally different in case of the strong saw-tooth magnetic substorms.

  20. Potential structures and particle acceleration on auroral field lines

    NASA Astrophysics Data System (ADS)

    Gorney, D. J.

    Observations of plasmas and electric field activity within regions of auroral particle acceleration have verified the existence of electric fields with components parallel to the magnetic field over large altitude regions. Evidence is presented which indicates that small-ampliatude double layers along the auroral magnetic field lines may provide a mechanism for the maintenance of auroral ion potential. Evidence is also presented of downward-directed parallel electric fields along the magnetic field lines in the return current region. It is suggested that the downward electric fields may have significant effects on ion trajectories, and further theoretical investigation of the effects of downward parallel electric fields on ion conic formation is recommended.

  1. M-I coupling across the auroral oval at dusk and midnight: repetitive substorm activity driven by interplanetary coronal mass ejections (CMEs)

    NASA Astrophysics Data System (ADS)

    Sandholt, P. E.; Farrugia, C. J.; Denig, W. F.

    2014-04-01

    We study substorms from two perspectives, i.e., magnetosphere-ionosphere coupling across the auroral oval at dusk and at midnight magnetic local times. By this approach we monitor the activations/expansions of basic elements of the substorm current system (Bostrøm type I centered at midnight and Bostrøm type II maximizing at dawn and dusk) during the evolution of the substorm activity. Emphasis is placed on the R1 and R2 types of field-aligned current (FAC) coupling across the Harang reversal at dusk. We distinguish between two distinct activity levels in the substorm expansion phase, i.e., an initial transient phase and a persistent phase. These activities/phases are discussed in relation to polar cap convection which is continuously monitored by the polar cap north (PCN) index. The substorm activity we selected occurred during a long interval of continuously strong solar wind forcing at the interplanetary coronal mass ejection passage on 18 August 2003. The advantage of our scientific approach lies in the combination of (i) continuous ground observations of the ionospheric signatures within wide latitude ranges across the auroral oval at dusk and midnight by meridian chain magnetometer data, (ii) "snapshot" satellite (DMSP F13) observations of FAC/precipitation/ion drift profiles, and (iii) observations of current disruption/near-Earth magnetic field dipolarizations at geostationary altitude. Under the prevailing fortunate circumstances we are able to discriminate between the roles of the dayside and nightside sources of polar cap convection. For the nightside source we distinguish between the roles of inductive and potential electric fields in the two substages of the substorm expansion phase. According to our estimates the observed dipolarization rate (δ Bz/δt) and the inferred large spatial scales (in radial and azimuthal dimensions) of the dipolarization process in these strong substorm expansions may lead to 50-100 kV enhancements of the cross

  2. Solar cycle and diurnal dependence of auroral structures

    NASA Astrophysics Data System (ADS)

    Partamies, N.; Whiter, D.; Syrjäsuo, M.; Kauristie, K.

    2014-10-01

    In order to facilitate usage of optical data in space climate studies, we have developed an automated algorithm to quantify the complexity of auroral structures as they appear in ground-based all-sky images. The image analysis is based on a computationally determined "arciness" value, which describes how arc like the auroral structures in the image are. With this new automatic method we have analyzed the type of aurora in about 1 million images of green aurora (λ = 557.7nm) captured at five camera stations in Finnish and Swedish Lapland in 1996-2007. We found that highly arc like structures can be observed in any time sector and their portion of the auroral structures varies much less than the fraction of more complex forms. The diurnal distribution of arciness is in agreement with an earlier study with high arc occurrence rate in the evening hours and steadily decreasing toward the late morning hours. The evolution of less arc-like auroral structures is more dependent on the level of geomagnetic activity and solar cycle than the occurrence of arcs. The median arciness is higher during the years close to the solar minimum than during the rest of the solar cycle. Unlike earlier proposed, the occurrence rate of both arcs and more complex auroral structures increases toward the solar maximum and decreases toward the solar minimum. The cyclic behavior of auroral structures seen in our data is much more systematic and clear than previously reported visual studies suggest. The continuous arciness index describing the complexity of auroral structures can improve our understanding on auroral morphology beyond the few commonly accepted structure classes, such as arcs, patches, and omega bands. Arciness can further be used to study the relationship of auroral structures at different complexity levels and magnetospheric dynamics.

  3. Morphology of auroral zone radio wave scintillation

    SciTech Connect

    Rino, C.L.; Matthews, S.J.

    1980-08-01

    This paper describes the morphology of midnight sector and morning sector auroral zone scintillation observations made over a two-year period using the Wideband satelite, which is in a sun-synchronous, low-altitude orbit. No definitive seasonal variation was found. The nighttime data showed the highest scintillation ocurrence levels, but significant amounts of morning scintillation were observed. For the most part the scintillation activity followed the general pattern of local magnetic activity. The most prominent feature in the nightime data is a localized amplitude and phase scintillation enhancement at the point where the propagation vector lies within an L shell. A geometrical effect due to a dynamic slab of sheetlike structures in the F region is hypothesized as the source of his enhancement. The data have been sorted by magnetic activity, proximity to local midnight, and season. The general features of the data are in agreement with the accepted morphology of auroral zone scintillation.

  4. Landau damping of auroral hiss

    NASA Technical Reports Server (NTRS)

    Morgan, D. D.; Gurnett, D. A.; Menietti, J. D.; Winningham, J. D.; Burch, J. L.

    1994-01-01

    Auroral hiss is observed to propagate over distances comparable to an Earth radius from its source in the auroral oval. The role of Landau damping is investigated for upward propagating auroral hiss. By using a ray tracing code and a simplified model of the distribution function, the effect of Landau damping is calculated for auroral hiss propagation through the environment around the auroral oval. Landau damping is found to be the likely mechanism for explaining some of the one-sided auroral hiss funnels observed by Dynamics Explorer 1. It is also found that Landau damping puts a lower limit on the wavelength of auroral hiss. Poleward of the auroral oval, Landau damping is found in a typical case to limit omega/k(sub parallel) to values of 3.4 x 10(exp 4) km/s or greater, corresponding to resonance energies of 3.2 keV or greater and wavelengths of 2 km or greater. For equatorward propagation, omega/k(sub parallel) is limited to values greater than 6.8 x 10(exp 4) km/s, corresponding to resonance energies greater than 13 keV and wavelengths greater than 3 km. Independent estimates based on measured ratios of the magnetic to electric field intensity also show that omega/k(sub parallel) corresponds to resonance energies greater than 1 keV and wavelengths greater than 1 km. These results lead to the difficulty that upgoing electron beams sufficiently energetic to directly generate auroral hiss of the inferred wavelength are not usually observed. A partial transmission mechanism utilizing density discontinuities oblique to the magnetic field is proposed for converting auroral hiss to wavelengths long enough to avoid damping of the wave over long distances. Numerous reflections of the wave in an upwardly flared density cavity could convert waves to significantly increased wavelengths and resonance velocities.

  5. Global Auroral Remote Sensing Using GGS UVI Images

    NASA Technical Reports Server (NTRS)

    Germany, G. A.; Parks, G. K.; Brittnacher, M. J.; Spann, J. F., Jr.; Cumnock, J.; Lummerzheim, D.

    1997-01-01

    The GGS POLAR satellite, with an apogee distance of 9 Earth radii, provides an excellent platform for extended viewing of the northern auroral zone. Global FUV auroral images from the Ultraviolet Imager onboard the POLAR satellite can be used as quantitative remote diagnostics of the auroral regions, yielding estimates of incident energy characteristics, compositional changes, and other higher order data products. In particular, images of long and short wavelength Earth Far Ultraviolet (FUV) Lyman-Birge-Hopfield (LBH) emissions can be modeled to obtain functions of energy flux and average energy that are basically insensitive to changes in seasonal and solar activity changes. The determination of maps of incident auroral energy characteristics is demonstrated here and compared with in situ measurements.

  6. Problems with mapping the auroral oval and magnetospheric substorms

    NASA Astrophysics Data System (ADS)

    Antonova, E. E.; Vorobjev, V. G.; Kirpichev, I. P.; Yagodkina, O. I.; Stepanova, M. V.

    2015-10-01

    Accurate mapping of the auroral oval into the equatorial plane is critical for the analysis of aurora and substorm dynamics. Comparison of ion pressure values measured at low altitudes by Defense Meteorological Satellite Program (DMSP) satellites during their crossings of the auroral oval, with plasma pressure values obtained at the equatorial plane from Time History of Events and Macroscale Interactions during Substorms (THEMIS) satellite measurements, indicates that the main part of the auroral oval maps into the equatorial plane at distances between 6 and 12 Earth radii. On the nightside, this region is generally considered to be a part of the plasma sheet. However, our studies suggest that this region could form part of the plasma ring surrounding the Earth. We discuss the possibility of using the results found here to explain the ring-like shape of the auroral oval, the location of the injection boundary inside the magnetosphere near the geostationary orbit, presence of quiet auroral arcs in the auroral oval despite the constantly high level of turbulence observed in the plasma sheet, and some features of the onset of substorm expansion.

  7. Auroral effects on midlatitude semidiurnal tides

    SciTech Connect

    Fesen, C.G. ); Richmond, A.D.; Roble, R.G. )

    1991-03-01

    The effect of auroral activity on mid-latitude semidiurnal tides was investigated using simulations from the NCAR Thermosphere/Ionosphere General Circulation Model (TIGCM). Model runs were made for solar cycle minimum equinox conditions for four levels of geomagnetic activity parameterized by the total hemispheric power index and the cross polar cap potential drop. Simulations at 42.5{degree}N (gg) predicted that the upper thermosphere semidiurnal winds and temperatures generally increase with increasing geomagnetic activity, while the lower thermosphere fields were relatively insensitive to the level of auroral forcing in the model. The modeled semidiurnal mid-latitude tidal response was determined by the magnitude and phasing of the waves generated by in situ solar forcing and the auroral momentum and energy sources, in conjunction with those propagating up from the lower atmosphere. The predicted sensitivity of the model tides to the level of geomagnetic activity may contribute to the observed tidal variability at mid latitudes. Successful modeling of observations will require careful specification of the high-latitude energy and momentum sources.

  8. Auroral interactions with ISSA

    NASA Technical Reports Server (NTRS)

    Purvis, Carolyn K.; Snyder, David B.; Jongeward, Gary A.

    1994-01-01

    Due to its high inclination orbit, International Space Station Alpha (ISSA) will occasionally experience surface charging by the high energy electrons of the auroral environment. This study looks at the frequency of these occurrences and recapitulates a charging model. ISSA should expect about 80 auoral encounters annually. If the plasma contactor is not run continuously, the vehicle may charge several hundred volts. Charge storage on standard space station coatings should not be a problem, but care must be taken that materials are not introduced inadvertently that cannot bleed off accumulated charge in a reasonable time. A conductivity requirement may be used to ensure surface materials do not charge to high voltages, or store charge for long periods of time.

  9. Characteristics of the solar wind controlled auroral emissions

    NASA Astrophysics Data System (ADS)

    Liou, K.; Newell, P. T.; Meng, C.-I.; Brittnacher, M.; Parks, G.

    1998-08-01

    We performed a high-time resolution (5 min) correlative study of the energy deposition rate in the northern auroral zone with the concurrent solar wind plasma and interplanetary magnetic field (IMF) observations for a 4 month period from March 30 to July 29, 1996. Auroral power, inferred by auroral emissions, was derived from images acquired by the ultraviolet imager (UVI) on board the Polar satellite, and the interplanetary parameters were based on Wind observations. It is found that dayside aurorae in the afternoon sector (65°-80° magnetic latitude (MLAT) and 1300-1800 magnetic local time (MLT)) are more active for large IMF cone angles and large solar wind electric fields. This result can be attributed to the manifestation of the antiparallel magnetic field merging in different locations and the partial ``penetration'' of the IMF on the dayside magnetopause. The integrated nightside (60°-75° MLAT and 2000-0100 MLT) auroral brightness is moderately correlated with the north-south component of the IMF and the solar wind speed with correlation coefficients of 0.49 and 0.35, respectively. The mean nightside auroral power is found to be approximately linearly proportional to the IMF Bz with a constant slope of 2 GW/nT. The solar wind speed, however, affects the nightside auroral power for both polarities of IMF Bz. Interestingly, the solar wind dynamic pressure shows no effect on the nightside auroral brightness. All these findings indicate that both reconnection and viscous-like interaction mechanisms play an important role in producing auroral emissions in the night sector. It is also found that the nightside auroral brightness responds to the southward turning of the IMF with a peak delay time of ~60 min. This result favors the model of loading-unloading magnetosphere. We also found that a negative IMF By condition favors the nightside auroral activity, and we attributed this effect to the partial penetration of the IMF By. Finally, the response function for

  10. Examining auroral downward current region processes using ground based data

    NASA Astrophysics Data System (ADS)

    Michell, Robert Gregory

    This thesis presents data from ground camera observations of the aurora conducted from Alaska during the winters of 2005 through 2007. In conjunction with these camera observations, conjugate radar observations of the auroral ionosphere were conducted during the winters of 2006 and 2007, using the Poker Flat Advanced Modular Incoherent Scatter Radar (AMISR). Two main aspects of auroral downward-current (DCR) and time-varying/polar cap boundary regions are investigated, namely, dark auroral signatures in the camera data, and naturally enhanced ion acoustic lines (NEIALs) in the radar data. An auroral event containing a distinct dark stripe occurred on 06 March 2005 over Kaktovik, Alaska. This event displayed many characteristics of an auroral DCR, as compared to in situ studies of DCRs using data from the FAST and Cluster satellites. It is shown that this dark stripe is the auroral signature of a downward-current region. This stripe was found to widen at a rate of 750 m/s, which is consistent with the predictions from the theory and model of DCRs (Streltsov and Marklund, 2006). The second aspect of these auroral regions investigated here is the occurrence of NEIALs in the radar data. Observations of NEIALs are presented from two separate nights, displaying different auroral context. On 08 February 2007, one short-lived NEIAL event was observed with AMISR using high-time resolution (˜19 ms). These raw data reveal that the large returns associated with the NEIALs come from the dark region immediately adjacent to an active dynamic auroral arc. It was also found that propagation in altitude of the NEIALs occurs at or near the Alfven velocity. Furthermore, it was found that the enhanced up- and down-shifted shoulders of the NEIALs most often occurred independently of one another on a 19 ms timescale. On 31 March 2006, a moderately intense auroral arc, (˜10 kR at 557.7 nm), was located in the local magnetic zenith at Poker Flat, Alaska. During this event the radar

  11. Characteristics of Extreme Auroral Charging Events

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Willis, Emily; Parker, Linda Neergaard

    2014-01-01

    Today’s presentation describes preliminary results from a study of extreme auroral charging in low Earth orbit. Goal of study is to document characteristics of auroral charging events of importance to spacecraft design, operations, and anomaly investigations.

  12. Electron and Proton Auroral Dynamics

    NASA Technical Reports Server (NTRS)

    Mende, S. B.; Frey, H. U.; Gerard, J. C.; Hubert, B.; Fuselier, S.; Spann, J. F., Jr.; Gladstone, R.; Burch, J. L.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Data from the Wide-band Imaging Camera (WIC) sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha were analyzed during a high altitude orbit segment of the IMAGE spacecraft. This segment began during the expansive phase of a substorm. The aurora changed into a double oval configuration, consisting of a set of discrete pole-ward forms and a separate diffuse auroral oval equatorwards, Although IMF Bz was strongly southward considerable activity could be seen poleward of the discrete auroras in the region that was considered to be the polar cap. The SI12 Doppler shifted Lyman alpha signature of precipitating protons show that the proton aurora is on the equatorward side of the diffuse aurora. In the following several hours the IMF Bz field changed signed. Although the general character of the proton and electron aurora did not change, the dayside aurora moved equatorward when the Bz was negative and more bright aurora was seen in the central polar cap during periods of positive Bz.

  13. Custom auroral electrojet indices calculated by using MANGO value-added services

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.; Moore, W. B.; King, T. A.

    2009-12-01

    A set of computational routines called MANGO, Magnetogram Analysis for the Network of Geophysical Observatories, is utilized to calculate customized versions of the auroral electrojet indices, AE, AL, and AU. MANGO is part of an effort to enhance data services available to users of the Heliophysics VxOs, specifically for the Virtual Magnetospheric Observatory (VMO). The MANGO value-added service package is composed of a set of IDL routines that decompose ground magnetic field observations to isolate secular, diurnal, and disturbance variations of magnetic field disturbance, station-by-station. Each MANGO subroutine has been written in modular fashion to allow "plug and play"-style flexibility and each has been designed to account for failure modes and noisy data so that the programs will run to completion producing as much derived data as possible. The capabilities of the MANGO service package will be demonstrated through their application to the study of auroral electrojet current flow during magnetic substorms. Traditionally, the AE indices are calculated by using data from about twelve ground stations located at northern auroral zone latitudes spread longitudinally around the world. Magnetogram data are corrected for secular variation prior to calculating the standard version of the indices but the data are not corrected for diurnal variations. A custom version of the AE indices will be created by using the MANGO routines including a step to subtract diurnal curves from the magnetic field data at each station. The custom AE indices provide more accurate measures of auroral electrojet activity due to isolation of the sunstorm electrojet magnetic field signiture. The improvements in the accuracy of the custom AE indices over the tradition indices are largest during the northern hemisphere summer when the range of diurnal variation reaches its maximum.

  14. Rocket study of auroral processes

    NASA Technical Reports Server (NTRS)

    Arnoldy, R. L.

    1981-01-01

    Abstracts are presented of previously published reports analyzing data from three Echo 3 rocket flights. Particle experiments designed for the Terrier-Malmute flight, the Echo 5 flight, and the Norwegian Corbier Ferdinand 50 flight are described and their flight performance evaluated. Theoretical studies on auroral particle precipitation are reviewed according to observations made in three regions of space: (1) the region accessible to rockets and low altitude satellites (few hundred to a few thousand kilometers); (2) the region extending from 4000 to 8000 km (S3-3 satellite range); and (3) near the equatorial plane (geosynchronous satellite measurements). Questions raised about auroral arc formation are considered.

  15. Electrodynamic response of the middle atmosphere to auroral pulsations

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.; Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Barcus, J. R.

    1990-01-01

    The MAC/EPSILON observational campaign encompassed the use of two Nike Orion rocket payloads which studied the effects of auroral energetics on the middle atmosphere. While one payload was launched during the recovery phase of a moderate magnetic substorm, during fairly stable auroral conditions, the other was launched during highly active postbreakup conditions during which Pc5 pulsations were in progress. The energetic radiation of the first event was composed almost entirely of relativistic electrons below 200 keV, while that of the second was dominated by much softer electrons whose high X-ray fluxes exceeded the cosmic ray background as an ionizing source down to below 30 km.

  16. Jupiter's Various Auroral Emission Enhancements Observed by Hisaki/EXCEED

    NASA Astrophysics Data System (ADS)

    Tao, Chihiro

    2016-07-01

    Onboard a JAXA Earth-orbiting platform, the planetary telescope Hisaki monitors extreme ultraviolet emissions from Jovian aurora and Io plasma torus continuously. Hisaki succeeded to detect sporadic, large auroral power enhancements displaying both short- (<1 planetary rotation) and long-term (>a few rotations) variations and their modulations by Io's volcanic activity over several weeks. The spectral information taken by Hisaki enables us to investigate (1) the time variation of the auroral electron precipitating fluxes during these emission enhancements, (2) the occurrence statistics of polar-dominant events, and (3) the associated magnetospheric dynamics for these emission enhancement events using Knight's aurora acceleration theory. Expected collaborative observations with Juno will be discussed.

  17. Global Auroral Energy Deposition Compared with Magnetic Indices

    NASA Technical Reports Server (NTRS)

    Brittnacher, M. J.; Fillingim, M. O.; Elsen, R.; Parks, G. K.; Germany, G. A.; Spann, J. F., Jr.

    1997-01-01

    Measurement of the global rate of energy deposition in the ionosphere via auroral particle precipitation is one of the primary goals of the Polar UVI program and is an important component of the ISTP program. The instantaneous rate of energy deposition for the entire month of January 1997 has been calculated by applying models to the UVI images and is presented by Fillingim et al. in this session. Magnetic indices, such as Kp, AE, and Dst, which are sensitive to variations in magnetospheric current systems have been constructed from ground magnetometer measurements and employed as measures of activity. The systematic study of global energy deposition raises the possibility of constructing a global magnetospheric activity index explicitly based on particle precipitation to supplement magnetic indices derived from ground magnetometer measurements. The relationship between global magnetic activity as measured by these indices and the rate of total global energy loss due to precipitation is not known at present. We study the correlation of the traditional magnetic index of Kp for the month of January 1997 with the energy deposition derived from the UVI images. We address the question of whether the energy deposition through particle precipitation generally matches the Kp and AE indices, or the more exciting, but distinct, possibility that this particle-derived index may provide an somewhat independent measure of global magnetospheric activity that could supplement traditional magnetically-based activity indices.

  18. Theory of the auroral magnetosphere

    NASA Technical Reports Server (NTRS)

    Schulz, M.; Chiu, Y. T.; Cornwall, J. M.

    1981-01-01

    The aurora has come to be understood as a manifestation of energy transfer and plasma transfer from the solar wind to the magnetosphere. The auroral oval seems to be a mapping of the boundary layer that lies just inside the magnetospheric surface, which consists of the magnetopause and neutral sheet. The auroral oval is consequently a region of reversal for the meridional (r,8) component of the magnetospheric convection electric field and thus a region of strong shear in the plasma drift velocity field. The velocity shear seems to account for the formation of eddies in the auroral "curtain". Moreover, the Kinematical impedance associated with hot auroral plasma perpendicular electric field across a narrow region of latitude to occur without the formation of a large parallel electric field. The signature of the parallel electric field is such as to produce upgoing ion beams and precipitating electron beams in the PM (afternoon-evening) sector of local time, and to account for the polarity of Region-1 currents as a function of local time.

  19. Global Auroral Imaging for the Dynamics Explorer Mission

    NASA Technical Reports Server (NTRS)

    Frank, L. A.

    1998-01-01

    The two Dynamics Explorer spacecraft, DE-1 and DE-2, were launched on August 3, 1981, into polar coplanar orbits at different altitudes for the purpose of studying interactive processes within the atmosphere-ionosphere-magnetosphere system. The DE-1 spacecraft (high-altitude mission) used an elliptical orbit that was selected to allow: (1) measurements extending from the hot magnetospheric plasma through the plasmasphere to the cool ionosphere; (2) global auroral imaging, wave measurements in the heart of the magnetosphere, and crossing of auroral field lines at several earth radii; and (3) measurements for significant periods of time along a magnetic field flux tube. The orbit of Dynamics Explorer 1 offered an opportunity to obtain global images of Earth's dayglow and auroral luminosities and to acquire consecutive images of the entire auroral oval during the growth, onset, expansion, and recovery phases of substorms. The University of Iowa's Spin-scan Auroral Imaging (SAI) instrument, was on-board DE-1. SAI was activated in orbit and placed in routine operation on September 23, 1981, and has provided outstanding new contributions in the fields of auroral, magnetospheric and geocoronal physics, introduced a powerful tool for the study of global atmospheric ozone, and initiated the first search from space for marine bioluminescence on the surface of the global ocean. The SAI instrumentation consists of three imaging photometers, two for visible wavelengths and the third for vacuum-ultraviolet wavelengths equipped with primary catoptric optics with superpolished mirror surfaces. The primary focusing element is an off-axis section of a parabolic mirror that is used to provide an optical path completely free of support structures for the mirrors.

  20. Active Fire Mapping Program

    MedlinePlus

    ... Incidents (Home) New Large Incidents Fire Detection Maps MODIS Satellite Imagery VIIRS Satellite Imagery Fire Detection GIS ... Data Web Services Latest Detected Fire Activity Other MODIS Products Frequently Asked Questions About Active Fire Maps ...

  1. DMSP Spacecraft Charging in Auroral Environments

    NASA Technical Reports Server (NTRS)

    Colson, Andrew; Minow, Joseph

    2011-01-01

    The Defense Meteorological Satellite Program (DMSP) spacecraft are a series of low-earth orbit (LEO) satellites whose mission is to observe the space environment using the precipitating energetic particle spectrometer (SSJ/4-5). DMSP satellites fly in a geosynchronous orbit at approx.840 km altitude which passes through Earth s ionosphere. The ionosphere is a region of partially ionized gas (plasma) formed by the photoionization of neutral atoms and molecules in the upper atmosphere of Earth. For satellites in LEO, such as DMSP, the plasma density is usually high and the main contributors to the currents to the spacecraft are the precipitating auroral electrons and ions from the magnetosphere as well as the cold plasma that constitutes the ionosphere. It is important to understand how the ionosphere and auroral electrons can accumulate surface charges on satellites because spacecraft charging has been the cause of a number of significant anomalies for on-board instrumentation on high altitude spacecraft. These range from limiting the sensitivity of measurements to instrument malfunction depending on the magnitude of the potential difference over the spacecraft surface. Interactive Data Language (IDL) software was developed to process SSJ/4-5 electron and ion data and to create a spectrogram of the particles number and energy fluxes. The purpose of this study is to identify DMSP spacecraft charging events and to present a preliminary statistical analysis. Nomenclature

  2. Ionospheric influence on the global characteristics of electron precipitation during auroral substorms

    NASA Astrophysics Data System (ADS)

    Chua, Damien Han

    Global auroral images from the Polar Ultraviolet Imager (UVI) and in situ, low altitude particle measurements from the Fast Auroral Snapshot Explorer (FAST) spacecraft are used to investigate the effects of solar wind variations and seasonal variability in the ionosphere on electron precipitation during auroral substorms. Isolated substorms and storm-time, pressure pulse-driven intensifications are compared and we show that the global patterns of precipitating electron energy flux and average energy are markedly different for each class of auroral phenomena. Field-aligned acceleration of auroral electrons in the upward current regions is found to be an essential aspect of the global aurora during isolated substorms. In contrast, the electron precipitation during pressure pulse-driven intensifications is less structured with no indication of field-aligned acceleration. A new method of quantifying the time scales and phases of magnetospheric substorms using the hemispheric power derived from the UVI images is described. We show that substorm time scales vary most strongly with season while IMF orientation plays a secondary role. The recovery time for substorm activity is roughly a factor of two longer when the nightside auroral zone is in darkness (winter and equinox) than when it is sunlit. We find that the longer time scale of substorms occurring in darkness is sustained by discrete auroral features associated with field-aligned potential drops and inertial Alfven waves. These discrete structures exist for shorter time scales, if they are observed at all, during substorms that occur under sunlit conditions. The observed seasonal variations in global auroral structure during substorms are most consistent with the hypothesis that ionospheric boundary conditions strongly influence the effectiveness of auroral acceleration mechanisms that include parallel potentials and Alfven waves. The results presented in this thesis will enhance our understanding of substorm

  3. The auroral footprint of Enceladus on Saturn.

    PubMed

    Pryor, Wayne R; Rymer, Abigail M; Mitchell, Donald G; Hill, Thomas W; Young, David T; Saur, Joachim; Jones, Geraint H; Jacobsen, Sven; Cowley, Stan W H; Mauk, Barry H; Coates, Andrew J; Gustin, Jacques; Grodent, Denis; Gérard, Jean-Claude; Lamy, Laurent; Nichols, Jonathan D; Krimigis, Stamatios M; Esposito, Larry W; Dougherty, Michele K; Jouchoux, Alain J; Stewart, A Ian F; McClintock, William E; Holsclaw, Gregory M; Ajello, Joseph M; Colwell, Joshua E; Hendrix, Amanda R; Crary, Frank J; Clarke, John T; Zhou, Xiaoyan

    2011-04-21

    Although there are substantial differences between the magnetospheres of Jupiter and Saturn, it has been suggested that cryovolcanic activity at Enceladus could lead to electrodynamic coupling between Enceladus and Saturn like that which links Jupiter with Io, Europa and Ganymede. Powerful field-aligned electron beams associated with the Io-Jupiter coupling, for example, create an auroral footprint in Jupiter's ionosphere. Auroral ultraviolet emission associated with Enceladus-Saturn coupling is anticipated to be just a few tenths of a kilorayleigh (ref. 12), about an order of magnitude dimmer than Io's footprint and below the observable threshold, consistent with its non-detection. Here we report the detection of magnetic-field-aligned ion and electron beams (offset several moon radii downstream from Enceladus) with sufficient power to stimulate detectable aurora, and the subsequent discovery of Enceladus-associated aurora in a few per cent of the scans of the moon's footprint. The footprint varies in emission magnitude more than can plausibly be explained by changes in magnetospheric parameters--and as such is probably indicative of variable plume activity. PMID:21512570

  4. The auroral footprint of Enceladus on Saturn.

    PubMed

    Pryor, Wayne R; Rymer, Abigail M; Mitchell, Donald G; Hill, Thomas W; Young, David T; Saur, Joachim; Jones, Geraint H; Jacobsen, Sven; Cowley, Stan W H; Mauk, Barry H; Coates, Andrew J; Gustin, Jacques; Grodent, Denis; Gérard, Jean-Claude; Lamy, Laurent; Nichols, Jonathan D; Krimigis, Stamatios M; Esposito, Larry W; Dougherty, Michele K; Jouchoux, Alain J; Stewart, A Ian F; McClintock, William E; Holsclaw, Gregory M; Ajello, Joseph M; Colwell, Joshua E; Hendrix, Amanda R; Crary, Frank J; Clarke, John T; Zhou, Xiaoyan

    2011-04-21

    Although there are substantial differences between the magnetospheres of Jupiter and Saturn, it has been suggested that cryovolcanic activity at Enceladus could lead to electrodynamic coupling between Enceladus and Saturn like that which links Jupiter with Io, Europa and Ganymede. Powerful field-aligned electron beams associated with the Io-Jupiter coupling, for example, create an auroral footprint in Jupiter's ionosphere. Auroral ultraviolet emission associated with Enceladus-Saturn coupling is anticipated to be just a few tenths of a kilorayleigh (ref. 12), about an order of magnitude dimmer than Io's footprint and below the observable threshold, consistent with its non-detection. Here we report the detection of magnetic-field-aligned ion and electron beams (offset several moon radii downstream from Enceladus) with sufficient power to stimulate detectable aurora, and the subsequent discovery of Enceladus-associated aurora in a few per cent of the scans of the moon's footprint. The footprint varies in emission magnitude more than can plausibly be explained by changes in magnetospheric parameters--and as such is probably indicative of variable plume activity.

  5. Statistical study of NEIAL occurence in the PFISR data and correlated auroral forms

    NASA Astrophysics Data System (ADS)

    Michell, R. G.; Samara, M.

    2012-12-01

    Naturally Enhanced Ion Acoustic Lines (NEIALs) have been observed wth the Poker Flat Incoherent Scatter Radar (PFISR) ever since it began operating in 2006. The first few years of PFISR operation corresponded to a long, geomagnetically quiet solar minimum. During this time there were only a limited number of NEIALs observed with PFISR with simultaneous auroral imaging. The increases in solar activity that started occurring in 2011 and 2012 have resulted in significantly more active auroral structures over the PFISR radar at Poker Flat, AK. The increase in auroral activity has resulted in a large number of NEIALs observed with PFISR. The MOOSE imagers have been operating continuously since September 2011 and have made many auroral observations simultaneous to the PFISR observations of NEIALs. The larger number of NEIAL observations available now, make it possible to distinguish the range of auroral features that are associated with different aspects of the NEIAL observations. We aim to statistically catagorize the different types of auroral features that occur with NEIALs in the PFISR data, with the goal of gaining insight into the possible generation mechanisms of NEIALs.; PFISR electron density measurements (in 10^11 m^-3) showing strong NEIAL enhancements extending to greater than 700 km altitudes. ; All-sky image from 22 January 2012, showing tall rayed auroral structures at a time of strong NEIALs in the PFISR data.

  6. Fermi acceleration of auroral particles.

    NASA Technical Reports Server (NTRS)

    Sharber, J. R.; Heikkila, W. J.

    1972-01-01

    Review of a number of nighttime acceleration mechanisms proposed in the literature for the role of producing the keV nighttime auroral-particle fluxes. Parallel electric fields are rejected for several reasons, but particularly because of the observed simultaneous precipitation of electrons and protons. Acceleration in the neutral sheet is inadequate for producing the particle energies, the observed field-aligned pitch-angle distribution at high latitudes, and the spectral hardening toward lower latitudes. Neutral point mechanisms, although often suggested in principle, have never been demonstrated satisfactorily in theory or in practice. Pitch-angle scattering from a trapped population produced by transverse adiabatic compression is also incapable of producing the field-aligned distribution. It is therefore suggested that longitudinal or Fermi acceleration, which results from the known magnetospheric convection, is the main nighttime auroral acceleration mechanism. The argument is supported by data obtained with the soft-particle spectrometer on Isis 1.

  7. A classification of auroral types

    NASA Astrophysics Data System (ADS)

    Simmons, D. A. R.

    1998-10-01

    All the currently recognised auroral types have been drawn together in a single classification based on their geophysical characteristics. A brief portrait of the most typical features of each type is presented with special reference to geomagnetic latitude, geomagnetic time sector and mechanism of aurora production. These and other characteristics make it possible to compare and contrast the similarities and differences between the different types of aurora on a geophysical basis.

  8. Auroral signature of comet Shoemaker-Levy 9 in the jovian magnetosphere.

    PubMed

    Prangé, R; Engle, I M; Clarke, J T; Dunlop, M; Ballester, G E; Ip, W H; Maurice, S; Trauger, J

    1995-03-01

    The electrodynamic interaction of the dust and gas comae of comet Shoemaker-Levy 9 with the jovian magnetosphere was unique and different from the atmospheric effects. Early theoretical predictions of auroral-type processes on the comet magnetic field line and advanced modeling of the time-varying morphology of these lines allowed dedicated observations with the Hubble Space Telescope Wide Field Planetary Camera 2 and resulted in the detection of a bright auroral spot. In that respect, this observation of the surface signature of an externally triggered auroral process can be considered as a "magnetospheric active experiment" on Jupiter.

  9. Environmental health program activities

    NASA Technical Reports Server (NTRS)

    Bergtholdt, C. P.

    1969-01-01

    Activities reported include studies on toxic air contaminants, excessive noise, poor lighting, food sanitation, water pollution, and exposure to nonionizing radiation as health hazards. Formulations for a radiological health manual provide guidance to personnel in the procurement and safe handling of radiation producing equipment and Apollo mission planning. A literature search and development of a water analysis laboratory are outlined to obtain information regarding microbiological problems involving potable water, waste management, and personal hygiene.

  10. Decade of balloon observations of auroral X-rays

    SciTech Connect

    Venkatesan, D.; Vij, K.K.

    1981-01-01

    The paper describes balloon observations of bremsstrahlung X-rays carried out by the University of Calgary over the past decade which deal with morphological studies of auroral electron precipitation. The program concentrated on the understanding of the correlation between parent electrons and secondary X-rays, the study of microbursts, east-west and north-south extent of electron precipitation, and precipitation during pulsating auroras.

  11. Evolution of Jupiter's auroral-related stratospheric heating and chemistry

    NASA Astrophysics Data System (ADS)

    Sinclair, James; Orton, Glenn S.; Greathouse, Thomas K.; Fletcher, Leigh N.; Moses, Julianne I.; Hue, Vincent; Irwin, Patrick Gerard Joseph; Melin, Henrik; Giles, Rohini Sara

    2016-10-01

    Auroral processes on Jupiter are evident over a large range of wavelengths. Emission at X-ray, UV and near-infrared wavelengths highlights the precipitation of charged particles in Jupiter's ionosphere. Jupiter's auroral regions also exhibit enhanced mid-infrared emission of CH4 (7.8-μm), C2H2 (13-μm), C2H4 (10.5-μm) and C2H6 (12.2-μm), which indicates auroral processes modify the thermal structure and chemistry of the neutral stratosphere at pressures from 10 mbar to 10 μbar. In Sinclair et al., 2016a (submitted), 2016b (in preparation), we investigated these processes further by performing a retrieval analysis of Voyager-IRIS (Infrared Interferometer Spectrometer) observations measured in November 1979, Cassini-CIRS (Composite Infrared Spectrometer) observations measured in January 2001 and IRTF-TEXES (Texas Echelon Cross Echelle Spectrograph on NASA's Infrared Telescope Facility) spectra measured in December 2014. These datasets however captured Jupiter at significantly different epochs and thus the overall global evolution of atmospheric conditions as well as differences in spatial sampling, spectral resolution (and therefore vertical resolution in the atmosphere) have made inferences of the temporal evolution in auroral regions a challenge. However, in April 2016, we acquired IRTF-TEXES observations of Jupiter's high latitudes, using observing parameters very similar to those in December 2014. By performing a similar analysis of these observations and comparing results between December 2014 and April 2016, we can investigate the evolution of the thermal structure and chemistry in Jupiter's auroral regions over a 15 month timescale. The magnitude of temperature/composition changes and the altitudes at which they occur will provide insights into how auroral processes in the ionosphere propagate to the stratosphere. In particular, we can assess whether the evolution of stratospheric conditions in auroral regions is related to the decrease in solar activity

  12. Auroral origin of medium scale gravity waves in neutral composition and temperature

    NASA Technical Reports Server (NTRS)

    Chandra, S.; Spencer, N. W.; Krankowsky, D.; Laemmerzahl, P.

    1979-01-01

    The kinetic temperature and neutral composition data obtained from the Aeros B neutral atmosphere temperature experiment and the neutral and ion mass spectrometer show spatial structures characteristic of medium scale gravity waves with a wavelength in the range of several hundred kilometers. These waves are associated with auroral activity, and their spatial structure reflects the time history of the auroral electrojet. The medium scale gravity waves tend to propagate to mid-latitudes on the nightside. On the dayside their range is limited to high latitudes. Gravity waves are carriers of auroral energy to middle and low latitudes where they may cause irreversible changes in temperature via viscous dissipation. Since auroral activity occurs frequently, it is suggested that this energy reaches the mid-latitude region of the thermosphere much more frequently than is indicated by planetary magnetic indices.

  13. Temporal and spatial characteristics of auroral energy deposition

    NASA Astrophysics Data System (ADS)

    Hampton, D. L.; Conde, M.

    2015-12-01

    Auroral electron precipitation forms a complex and dynamic energy input into the high-latitude ionosphere and thermopshere. Rapid changes in plasma density due to electron impact ionization create correspondingly rapid changes in conductivity which in turn change the magnitude and altitude profile of magnetospheric current closure in the E- and F-region. Modeling these changes in the ionosphere and their effects on the local or regional upper atmosphere requires detailed input over wide regions. In support of the AMISR PINOT campaign and several rocket campaigns (CASCADES-2, MICA, ASSP) we have developed and tested a method to determine the characteristics of auroral energy input using purely ground-based optical measurements in geometries away from magnetic zenith. Using the N2+ first negative emissions at 427.8 nm reproduces the total energy flux over a wide region, but alone does not indicate the altitude profile of this energy deposition. Using temperature maps of the E-region collected by a Scanning Doppler Imager (SDI) observing the auroral green-line emission is a proxy for the characteristic energy of the precipitating electrons. While in some cases the energy determination underestimates the average energy it still is a good proxy for understanding when the electron distribution changes. We examine two seasons worth of auroral observations and determine the spatial and temporal variability of auroral energy deposition in comparison to solar wind and geophysical activity parameters. We also compare the results with well-known empirical models of electron energy deposition and show that they underestimate the peak local energy deposition rates by as much as a factor of 30.

  14. Active Sites Environmental Monitoring Program: Program plan

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  15. Electron precipitation in the midday auroral oval

    SciTech Connect

    Meng, C.

    1981-04-01

    Simultaneous observations of auroral displays and electron precipitations by the DMSP 33 satellite provide an excellent and unique opportunity to study precipitation characteristics of the midday auroral oval. Attention is given to two topics: (1) the nature of the 'gap' of the midday discrete auroras which is a permanent feature of the dayside auroral oval observed by both Isis 2 and DMSP satellites and (2) the relationship of this gap with the polar cusp region. Based on 2-month (June, July 1975) observations of the midday auroras over the southern hemisphere, it is found that inside the 'gap' of the discrete auroras along the dayside auroral oval, soft electron precipitations with a magnetosheathlike spectrum were invariably detected. The spatial extent of this region was about few degrees in latitude and about 2--3 hours in local time near 1130 magnetic local time meridian. No significant electron precipitation was detected poleward of the instantaneous midday auroral oval. Typical plasma sheet and discrete auroral types of electron precipitations were detected in the other parts of the midday auroral oval. Therefore it is proposed that the ionospheric projection of the polar cusp is a small region of the instantaneous dayside auroral oval near the noon meridian, coinciding with the 'gap' of the midday discrete auroras.

  16. Auroral Substorm Time Scales: Seasonal and IMF Variations

    NASA Technical Reports Server (NTRS)

    Chua, D.; Parks, G. K.; Brittnacher, M.; Germany, G. A.; Spann, J. F.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The time scales and phases of auroral substorm, activity are quantied in this study using the hemispheric power computed from Polar Ultraviolet Imager (UVI) images. We have applied this technique to several hundred substorm events and we are able to quantify how the characterist act, of substorms vary with season and IMF Bz orientation. We show that substorm time scales vary more strongly with season than with IMF Bz orientation. The recovery time for substorm. activity is well ordered by whether or not the nightside oral zone is sunlit. The recovery time scales for substorms occurring in the winter and equinox periods are similar and are both roughly a factor of two longer than in summer when the auroral oval is sunlit. Our results support the hypothesis that the ionosphere plays an active role in governing the dynamics of the aurora.

  17. The Auroral Particles experiment

    NASA Technical Reports Server (NTRS)

    1981-01-01

    An instrument for the detection of particles in the energy range of 0.1 ev to 80 Kev was designed, built, tested, calibrated, and flown onboard the spacecraft ATS-6. Data from this instrument generated the following research: intensive studies of the plasma in the vicinity of the spacecraft; global variations of plasmas; correlative studies using either other spacecraft or ground based measurements; and studies of spacecraft interactions with ambient plasmas including charging, local electric fields due to differential charging, and active control of spacecraft potential. Results from this research are presented.

  18. Preliminary Results from Recent Simultaneous Chandra/HST Observations of Jupiter Auroral Zones

    NASA Technical Reports Server (NTRS)

    Elsner, R.; Gladstone, R.; Waite, H.; Majeed, T.; Ford, P.; Grodent, D.; Bwardwaj, A.; Howell, R.; Cravens, T.; MacDowell, R.

    2003-01-01

    Jupiter was observed by the Chandra X-ray Observatory in late February, 2003, for 144 ks, using both the ACIS-S and HRC-I imaging x-ray cameras. Five orbits of HST STIS observations of the planet's northern auroral zone were obtained during the ACIS-S observations. These data are providing a wealth of information about Jupiter's auroral activity, including the first x-ray spectra from the x-ray hot spots inside the auroral ovals. We will also discuss the approximately 45 minute quasi-periodicity in the auroral x-ray emission - which correlates well with simultaneous observations of radio bursts by the Ulysses spacecraft - and a possible phase relation between the emission from the northern and southern x-ray aurora.

  19. Simulation of auroral double layers

    NASA Technical Reports Server (NTRS)

    Hubbard, R. F.; Joyce, G.

    1979-01-01

    Some basic properties of plasma double layers are deduced from a particle-in-cell computer simulation and related to parallel electric-field structures above the auroral regions. The simulation results on the processes leading to double-layer formation are examined, particularly in relation to the transient stage and double-layer structure and stability. It is concluded that: (1) a large potential difference applied to a finite-length plasma will be concentrated in a shocklike localized region instead of occurring over the entire length of the system; (2) the initial stage in double-layer formation is dominated by a large-potential pulse propagating in the direction of the induced electrostatic drift; (3) the entire potential is dropped over a specific scale length once the double layer has formed; and (4) this scale length is expected to be of the order of 1 km for a double layer above a discrete auroral arc with a potential of 10 kV and the electric-field vector parallel to the magnetic-field vector.

  20. Hemispheric Assymeries in Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Mende, S. B.

    2014-12-01

    It is widely accepted that the space weather related electrodynamic forcing of the geospace environment acts through the high geomagnetic latitude regions. At high latitudes inter-hemispheric asymmetries are largely due to the differences in solar illumination, the direction of the solar wind and interplanetary magnetic field components and to a lesser extent, due to differences between the two hemispheric internal fields. So far most research regarding interhemispheric differences concentrated on learning about the basic magnetosphere-ionosphere coupling mechanisms. It has been well established that sunlit conditions affect the energy flux of auroral precipitation resulting from the reduction in the mean energy of the auroral electrons in the sunlit summer hemisphere. This can be explained by the partial shorting out of the particle accelerating fields by the sunlight induced conductivity. It has also been found that sunlit conditions reduce the particle fluxes and therefore the associated field aligned currents. Unless the precipitation-induced conductivities overwhelm the sunlit component of conductivity, this would imply that the magnetospheric current generator responds to the ionospheric load in a highly non-linear manner. Interhemispheric currents may also play an important role that has not been fully explored. Interhemispheric asymmetries in substorm morphology have been explored critically because conjugacy implies that substorms have a common source at equatorial latitudes. In some cases the lack of conjugacy of substorms could be explained by considering the magnitude and direction of the IMF.

  1. Electron currents associated with an auroral band

    NASA Technical Reports Server (NTRS)

    Spiger, R. J.; Anderson, H. R.

    1975-01-01

    Measurements of electron pitch angle distributions and energy spectra over a broad auroral band were used to calculate net electric current carried by auroral electrons in the vicinity of the band. The particle energy spectrometers were carried by a Nike-Tomahawk rocket launched from Poker Flat, Alaska, at 0722 UT on February 25, 1972. Data are presented which indicate the existence of upward field-aligned currents of electrons in the energy range 0.5-20 keV. The spatial relationship of these currents to visual structure of the auroral arc and the characteristics of the electrons carrying the currents are discussed.

  2. Optical signatures of prenoon auroral precipitation: Sources and responses to solar wind variations

    SciTech Connect

    Jacobsen, B.; Sandholt, P.E.; Burke, W.J.

    1995-05-01

    Ground-based optical observations from Svalbard of 0900 - 1100 MLT auroral structures and dynamics are presented. Strong and stable red line emissions with weak, transient auroral activity were initially observed. The IMP 8 spacecraft, located outside the dawnside bow shock, detected large changes in interplanetary magnetic field (IMF) direction including a sharp transition from negative to positive IMF B{sub z} and a subsequent decrease in the solar wind density. A poleward expansion of the auroral display was seen in response to these variations, with a several minutes time delay, consistent with the location of IMP 8 relative to the magnetopause. The initial ionospheric response to these changes involved an intense brightening and northwestward drifts of discrete auroral forms. These effects may be connected with the decrease of external pressure and associated magnetopause perturbations. During the next 2-3 hours, quasi-periodic transient, discrete auroral forms were observed to expand in the antisunward direction. The morphology of the auroral forms detected in the prolonged period of northward IMF B{sub z} are compared with in situ measurements taken during a DMSP pass to the west of Svalbard and discussed in terms of several possible generation mechanisms. These include variations in external pressure, magnetic merging poleward of the cusp, and dynamo processes in the plasma mantle and/or low-latitude boundary layer, powered by intruding magnetosheath plasma elements. The optical measurements appear most consistent with expected effects of a magnetosheath plasma penetration of the plasma mantle. 32 refs., 5 figs.

  3. Optical signatures of prenoon, auroral precipitation: Sources and responses to solar wind variations

    SciTech Connect

    Jacobsen, B.; Sanholt, P.E.; Burke, W.J.; Denig, W.F.; Maynard, N.C.

    1995-05-01

    Ground-based optical observations from Svalbard of 0900 - I 100 MLT auroral structures and dynamics are presented. Strong and stable red line emissions with weak, transient auroral activity were initially observed. The IMP 8 spacecraft, located outside the dawnside bow shock, detected large changes in interplanetary magnetic field IMF direction including a sharp transition from negative to positive IMF B, and a subsequent decrease in the solar wind density. A poleward expansion of the auroral display was seen in response to these variations, with a several minutes time delay, consistent with the location of IMP 8 relative to the magnetopause. The initial ionospheric response to these changes involved an intense brightening and northwestward drifts of discrete auroral forms. These effects may be connected with the decrease of external pressure and associated magnetopause perturbations. During the next 2-3 hours, quasi-periodic transient, discrete auroral forms were observed to expand in the antisunward direction. The morphology of the auroral forms detected in the prolonged period of northward IMF B, are compared with in situ measurements taken during a DMSP pass to the west of Svalbard and discussed in terms of several possible generation mechanisms. These include variations in external pressure, magnetic merging poleward of the cusp, and dynamo processes in the plasma mantle and/or low-latitude boundary layer, powered by intruding magnetosheath plasma element. The optical measurements appear most consistent with expected effects of a magnetosheath plasma penetration of the plasma mantle.

  4. First Satellite Imaging of Auroral Pulsations by the Fast Auroral Imager on e-POP

    NASA Astrophysics Data System (ADS)

    Lui, A.; Cogger, L.; Howarth, A. D.; Yau, A. W.

    2015-12-01

    We report the first satellite imaging of auroral pulsations by the Fast Auroral Imager (FAI) onboard the Enhanced Polar Outflow Probe (e-POP) satellite. The near-infrared camera of FAI is capable of providing up to two auroral images per second, ideal for investigation of pulsating auroras. The auroral pulsations were observed within the auroral bulge formed during a substorm interval on 2014 February 19. This first satellite view of these pulsations from FAI reveals that (1) several pulsating auroral channels (PACs) occur within the auroral bulge, (2) periods of the intensity pulsations span over one decade within the auroral bulge, and (3) there is no apparent trend of longer pulsation periods associated with higher latitudes for these PACs. Although PACs resemble in some respect stable pulsating auroras reported previously but they have several important differences in characteristics.PACs are not embedded in or emerging from omega bands or torches and are located at significant distances from the equatorward boundary of the auroral oval, unlike the characteristics of stable pulsating auroras.

  5. New techniques for auroral irregularity studies with COSCAT

    NASA Astrophysics Data System (ADS)

    Eglitis, P.; McCrea, I. W.; Robinson, T. R.; Nygrén, T.; Schlegel, K.; Turunen, T.; Jones, T. B.

    1998-10-01

    The COSCAT system enables the detection of E-region auroral backscatter with the EISCAT remote receivers at magnetic aspect angles close to 90 °. This is achieved by utilising a low-power transmitter stationed in Oulu, Finland. Many important observations of E-region irregularities have been achieved with this simple experiment. Recent studies have attempted to push the COSCAT system to its experimental limits. Firstly, the CW signal has been phase-modulated with 13-bit Barker codes with baud lengths of 40, 70 and 100 µs. Interpretation of the received power allows the spatial distribution of the auroral scatterers to be determined. The second advance is in the use of a sophisticated correlator program which allows data to be buffered within the correlator at very high time resolution. This enables the coherent backscatter power to be sampled every 12.5 ms and the full auto-correlation function to be measured every 100 ms. These measurements allow the COSCAT system to be employed for the first time in an investigation of the growth and decay of the auroral irregularities.

  6. Auroral kilometric radiation source characteristics using ray tracing techniques

    NASA Astrophysics Data System (ADS)

    Schreiber, R.; Santolik, O.; Parrot, M.; Lefeuvre, F.; Hanasz, J.; Brittnacher, M.; Parks, G.

    2002-11-01

    3-D ray tracing to the presumed auroral kilometric radiation (AKR) source region has been performed using the input data from wave distribution function (WDF) based on the AKR waveforms recorded on board the Interball 2 satellite by the French wave experiment MEMO. Both the direction of the WDF maximum and the WDF form and angular size have been taken into account. Two instances of AKR emissions were observed on 28 January 1997 at 2037 and 2107 UT. Rays traced in R-X mode out of the s/c point toward two different active regions on the auroral oval (as seen with Polar UV imager after projection of the source region along the magnetic field lines down to the ionosphere level). Source region apparent angular sizes based on WDF are compatible with sizes estimated from signal modulation produced by electric antenna system rotation.

  7. Clean Coal Program Research Activities

    SciTech Connect

    Larry Baxter; Eric Eddings; Thomas Fletcher; Kerry Kelly; JoAnn Lighty; Ronald Pugmire; Adel Sarofim; Geoffrey Silcox; Phillip Smith; Jeremy Thornock; Jost Wendt; Kevin Whitty

    2009-03-31

    Although remarkable progress has been made in developing technologies for the clean and efficient utilization of coal, the biggest challenge in the utilization of coal is still the protection of the environment. Specifically, electric utilities face increasingly stringent restriction on the emissions of NO{sub x} and SO{sub x}, new mercury emission standards, and mounting pressure for the mitigation of CO{sub 2} emissions, an environmental challenge that is greater than any they have previously faced. The Utah Clean Coal Program addressed issues related to innovations for existing power plants including retrofit technologies for carbon capture and sequestration (CCS) or green field plants with CCS. The Program focused on the following areas: simulation, mercury control, oxycoal combustion, gasification, sequestration, chemical looping combustion, materials investigations and student research experiences. The goal of this program was to begin to integrate the experimental and simulation activities and to partner with NETL researchers to integrate the Program's results with those at NETL, using simulation as the vehicle for integration and innovation. The investigators also committed to training students in coal utilization technology tuned to the environmental constraints that we face in the future; to this end the Program supported approximately 12 graduate students toward the completion of their graduate degree in addition to numerous undergraduate students. With the increased importance of coal for energy independence, training of graduate and undergraduate students in the development of new technologies is critical.

  8. Auroral pulsations from ionospheric winds

    NASA Technical Reports Server (NTRS)

    Nakada, M. P.

    1989-01-01

    The possibility that auroral pulsations are due to oscillatory electrical circuits in the ionosphere that are driven by the negative resistance of jet stream winds is examined. For the condenser plates, the highly conducting surfaces above the edges of the jet stream are postulated. The dielectric constant of the plasma between the plates is quite large. The current that is driven perpendicular to and by the jet stream closes along the plates and through Pedersen currents in the F region above the stream. This closed loop gives the inductance and resistance for the circuit. Periods of oscillation for this circuit appear to be in the range of Pc 1 to Pc 3. In accord with observations, this circuit appears to be able to limit the brightness of pulsations.

  9. Cassini UVIS Auroral Observations in 2016

    NASA Astrophysics Data System (ADS)

    Pryor, Wayne R.; Jouchoux, Alain; Esposito, Larry W.; Radioti, Aikaterini; Grodent, Denis; Gustin, Jacques; Gerard, Jean-Claude; Lamy, Laurent; Badman, Sarah; Bunce, Emma; Cecconi, Baptiste; Clarke, John T.; Crary, Frank; Dougherty, Michele; Dyudina, Ulyana A.; Kurth, William; Mitchell, Don; Nichols, Jonathan; Prange, Renee; Schippers, Patricia; Zarka, Philippe; Cassini UVIS Team

    2016-10-01

    In June of 2016, the Cassini Saturn orbiter began a series of high inclination orbits that will continue until September 2017 when the mission ends as Cassini enters the Saturn atmosphere. These orbits present excellent views of Saturn's polar regions suitable for auroral imaging at the closest distances to date, with the additional prospect of simultaneous particle and fields measurements within the sources of Saturn Kilometric Radiation (SKR) associated with ultraviolet auroral emissions and/or acceleration regions likely coinciding with them. We will present new Cassini Ultraviolet Imaging Spectrograph (UVIS) auroral images, spectra and movies obtained during the summer and fall of 2016 and put them in the context of auroral data collected since Cassini orbit insertion in 2004. Included in the new data will be UVIS south polar observations obtained simultaneously with Hubble Space Telescope observations of the north polar region on June 29, 2016 and August 19, 2016.

  10. Detached auroral arcs in the trough region

    NASA Technical Reports Server (NTRS)

    Anger, C. D.; Moshupi, M. C.; Wallis, D. D.; Murphree, J. S.; Brace, L. H.; Shepherd, G. G.

    1978-01-01

    In a previous paper, Moshupi et al. (1977) have reported on the occurrence of rare auroral 'patches' equatorward of the normally well-defined boundary of diffuse aurora. Some less spectacular but more common arclike features were observed in the same 'trough' region (between the plasmapause and the auroral oval) during the period 1972-1975. These 'detached' arcs show some similarities to stable auroral red arcs in terms of their location and occurrence, but are completely different spectroscopically in that the stable auroral red arcs produce almost pure atomic oxygen red line emissions, whereas the detached arcs are deficient in red line emission - a feature implying totally different production mechanisms. The characteristics of the detached lines are described, including their unusual local time/longitude dependence.

  11. OVATION Prime Model and "Aurorasaurus" Auroral Observations

    NASA Video Gallery

    This video shows the auroral oval, as modeled using OVATION Prime (2013), along with citizen science reports collected by the Aurorasaurus project for the St. Patrick’s Day storm over March 17-19, ...

  12. Comment: An Apparent Controversy in Auroral Physics

    NASA Astrophysics Data System (ADS)

    Haerendel, Gerhard

    2007-03-01

    In his article ``A turning point in auroral physics,'' Bryant argued against what he called the `standard' theory of auroral acceleration, according to which the electrons ``gain their energy from static electric fields,'' and offered wave acceleration as an alternative. Because of the importance of the process, not only for the aurora borealis but also for other cosmic plasmas, a clarification of this apparent controversy seems to be in place.

  13. Electromagnetic interference impact of the proposed emitters for the High Frequency Active Auroral Research Program (HAARP). Interim report

    SciTech Connect

    Robertshaw, G.A.; Snyder, A.L.; Weiner, M.M.

    1993-05-14

    The proposed HAARP emitters at the Gakona (Alaska) preferred site and at the Clear AFS (Alaska) alternative site are the Ionospheric Research Instrument (IRI), the Incoherent Scatter Radar (ISR), and the Vertical Incidence Sounder(VIS). The electromagnetic interference (EMI) impact of those emitters on receiving systems in the vicinity of the sites is estimated in this study. The results are intended for use as an input to the Air Force Environmental Impact Statement as part of the Environmental Impact Analysis Process.

  14. High Frequency Active Auroral Research Program (HAARP) imager. Final report, 29 August 1991-29 August 1993

    SciTech Connect

    Lance, C.; Eather, R.

    1993-09-30

    A low-light-level monochromatic imaging system was designed and fabricated which was optimized to detect and record optical emissions associated with high-power rf heating of the ionosphere. The instrument is capable of detecting very low intensities, of the order of 1 Rayleigh, from typical ionospheric atomic and molecular emissions. This is achieved through co-adding of ON images during heater pulses and subtraction of OFF (background) images between pulses. Images can be displayed and analyzed in real time and stored in optical disc for later analysis. Full image processing software is provided which was customized for this application and uses menu or mouse user interaction.

  15. Electromagnetic plasma wave emissions from the auroral field lines

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.

    1977-01-01

    The most important types of auroral radio emissions are reviewed, both from a historical perspective as well as considering the latest results. Particular emphasis is placed on four types of electromagnetic emissions which are directly associated with the plasma on the auroral field lines. These emissions are (1) auroral hiss, (2) saucers, (3) ELF noise bands, and (4) auroral kilometric radiation. Ray tracing and radio direction finding measurements indicate that both the auroral hiss and auroral kilometric radiation are generated along the auroral field lines relatively close to the earth, at radial distances from about 2.5 to 5 R sub e. For the auroral hiss the favored mechanism appears to be amplified Cerenkov radiation. For the auroral kilometric radiation several mechanisms have been proposed, usually involving the intermediate generation of electrostatic waves by the precipitating electrons.

  16. Auroral kilometric radiation/aurora correlation

    NASA Technical Reports Server (NTRS)

    Benson, R. F.; Akasofu, S. I.

    1983-01-01

    Auroral kilometric radiation (AKR) observations from the ISIS 1 topside sounder receiver were compared with visual auroral observations from the network of Alaskan all-sky camera stations. The goal was to relate AKR source region encounters to specific auroral forms on the same magnetic field line. Thirty-eight simultaneous data sets were identified and analyzed. In general, intense AKR was associated with bright auroral arcs and conditions of weak or no AKR corresponded to times when either no aurora or only a faint arc or weak diffuse aurora were observed. Five cases, when both intense AKR and bright visual aurora were present, were analyzed in detail. Complete electron density N sub e contours, from the satellite altitude down to the F region ionization peak, were obtained along N-S traversals of the AKR source region. In addition, the ISIS 1 orbital tracks were projected down the magnetic field lines to the auroral altitude and compared to auroral features on a map derived from the all sky camera images. Density cavities (regions where N sub e 100/cu cm) were encountered on each of these passes.

  17. An interplanetary shock traced by planetary auroral storms from the Sun to Saturn.

    PubMed

    Prangé, Renée; Pallier, Laurent; Hansen, Kenneth C; Howard, Russ; Vourlidas, Angelos; Courtin, Régis; Parkinson, Chris

    2004-11-01

    A relationship between solar activity and aurorae on Earth was postulated long before space probes directly detected plasma propagating outwards from the Sun. Violent solar eruption events trigger interplanetary shocks that compress Earth's magnetosphere, leading to increased energetic particle precipitation into the ionosphere and subsequent auroral storms. Monitoring shocks is now part of the 'Space Weather' forecast programme aimed at predicting solar-activity-related environmental hazards. The outer planets also experience aurorae, and here we report the discovery of a strong transient polar emission on Saturn, tentatively attributed to the passage of an interplanetary shock--and ultimately to a series of solar coronal mass ejection (CME) events. We could trace the shock-triggered events from Earth, where auroral storms were recorded, to Jupiter, where the auroral activity was strongly enhanced, and to Saturn, where it activated the unusual polar source. This establishes that shocks retain their properties and their ability to trigger planetary auroral activity throughout the Solar System. Our results also reveal differences in the planetary auroral responses on the passing shock, especially in their latitudinal and local time dependences.

  18. Auroral effects on meteoric metals in the upper atmosphere

    NASA Astrophysics Data System (ADS)

    Heinselman, Craig James

    1999-12-01

    Meteors deposit many tons of material into Earth's upper atmosphere each day. The physics and chemistry of meteoric metals in the atmosphere have long been active topics of study, but sophisticated models have emerged just recently of the gas-phase chemical reactions that affect the evolution of the state of these metals. At high latitudes, this portion of the upper atmosphere is also shared by the aurora borealis, or northern lights, which dramatically alter the properties of the background plasma. This thesis concerns coupled chemical models and one- dimensional dynamical models that were developed to investigate the effects of auroral ionization on the time evolution of meteoric iron and sodium elements and compounds in the upper atmosphere. These models are used to show that aurorae can result in rapid ionization of recently deposited iron and sodium, with time constants on the order of 15 minutes. The models are also used to investigate the influence of aurorae on the background iron and sodium layers. Because of the nominal altitude of the neutral iron layer, aurorae will not normally have a measurable impact on that constituent. For sodium, on the other hand, the impact is more significant but highly dependent on the chemical makeup of the aurorally produced ions. For either case, sporadic neutral atom layers at auroral altitudes are significantly affected. A case study of radar and lidar measurements from the Sondrestrom Facility in Greenland is used to test the sodium model. Results are presented which are consistent with the model predictions of the effects of the aurorally enhanced ionization. For this specific case, evidence is also presented to support a gas-phase chemical mechanism for the formation of a thin the formation of a thin sporadic sodium layer.

  19. Auroral Spatial Structures Probe Sub-Orbital Mission Preliminary Results

    NASA Astrophysics Data System (ADS)

    Pratt, J.; Swenson, C.; Martineau, R. J.; Fish, C. S.; Conde, M.; Hampton, D.; Crowley, G.

    2015-12-01

    The NASA Auroral Spatial Structures Probe, 49.002, was launched January 28, 2015 from the Poker Flat Research Range into active aurora over the northern coast of Alaska. The primary objective of this mission was to determine the contribution of small spatial and temporal scale fluctuations of the electric fields to the larger-scale energy deposition processes associated with the aurora. The Auroral Spatial Structures Probe Sub-Orbital Mission consisted of a formation of 7 spacecraft (a main payload with 6 deployable sub-payloads) designed for multiple temporally spaced co-located measurements of electric and magnetic fields in the earth's ionosphere. The mission was able to make observations at a short time scale and small spatial scale convergence that is unobservable by either satellite or ground-based observations. The payloads included magnetometers, electric field double probes, and Langmuir probes as well as a sweeping impedance probe on the main payload. We present here preliminary results from the measurements taken that hint at the underlying spatial structure of the currents and energy deposition in the aurora. The Poynting flux derived from the observations is shown and implications are discussed in terms of the contribution of small spatial scale, rapid temporal scale fluctuations in the currents that deposit energy in the auroral region. Funding provided by NASA Grants NNX11AE23G and NNX13AN20A.

  20. Effects of Interplanetary Shock Inclinations on Nightside Auroral Power Intensity

    NASA Astrophysics Data System (ADS)

    Oliveira, D. M.; Raeder, J.; Tsurutani, B. T.; Gjerloev, J. W.

    2016-02-01

    We derive fast forward interplanetary (IP) shock speeds and impact angles to study the geoeffectiveness of 461 IP shocks that occurred from January 1995 to December 2013 using ACE and Wind spacecraft data. The geomagnetic activity is inferred from the SuperMAG project data. SuperMAG is a large chain which employs more than 300 ground stations to compute enhanced versions of the traditional geomagnetic indices. The SuperMAG auroral electroject SME index, an enhanced version of the traditional AE index, is used as an auroral power (AP) indicator. AP intensity jumps triggered by shock impacts are correlated with both shock speed and impact angle. It is found that high AP intensity events typically occur when high speed IP shocks impact the Earth's magnetosphere with the shock normal almost parallel to the Sun-Earth line. This result suggests that symmetric and strong magnetospheric compression leads to favorable conditions for intense auroral power release, as shown previously by simulations and observations. Some potential mechanisms will be discussed.

  1. Solar activity dependence of nightside aurora in winter conditions

    NASA Astrophysics Data System (ADS)

    Zhou, Su; Luan, Xiaoli; Dou, Xiankang

    2016-02-01

    The dependence of the nightside (21:00-03:00 MLT; magnetic local time) auroral energy flux on solar activity was quantitatively studied for winter/dark and geomagnetically quiet conditions. Using data combined from Thermosphere, Ionosphere, Mesosphere Energetics and Dynamics/Global Ultraviolet Imager and Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations, we separated the effects of geomagnetic activity from those of solar flux on the nightside auroral precipitation. The results showed that the nightside auroral power was reduced by ~42% in solar maximum (F10.7 = 200 sfu; solar flux unit 1 sfu = 10-22 W m-2 Hz-1) with respect to that under solar minimum (F10.7 = 70 sfu) for the Kp = 1 condition, and this change rate became less (~21%) for the Kp = 3 condition. In addition, the solar cycle dependence of nightside auroral power was similar with that from both the premidnight (21:00-23:00 MLT) and postmidnight (01:00-03:00 MLT) sectors. These results indicated that as the ionospheric ionization increases with the enhanced auroral and geomagnetic activities, the solar activity dependences of nightside auroral power become weaker, at least under geomagnetically quiet conditions.

  2. Modulation of auroral electrojet currents using dual HF beams with ELF phase offset

    NASA Astrophysics Data System (ADS)

    Golkowski, M.; Cohen, M.; Moore, R. C.

    2012-12-01

    The modulation of naturally occuring ionospheric currents with high power radio waves in the high frequency (HF, 3-10 MHz) band is a well known technique for generation of extremely low frequency (ELF, 3-3000 Hz) and very low frequency (VLF, 3-30 kHz) waves. We use the heating facility of the High Frequency Active Auroral Research Program (HAARP) to investigate the effect of using dual HF beams with an ELF/VLF phase offset between the modulation waveforms. Experiments with offset HF beams confirm the model of independent ELF/VLF sources. Experiments with co-located HF beams exhibit interaction between the first and second harmonics of the modulated tones when square and sine wave modulation waveforms are employed. Using ELF/VLF phase offsets for co-loacted beams is also shown to be a potential diagnostic for the D-region ionospheric profile.

  3. Relations between the Birkeland currents, the auroral electrojet indices and high latitude Joule heating

    NASA Technical Reports Server (NTRS)

    Nisbet, J. S.

    1982-01-01

    Field-aligned currents were postulated by Birkeland (1908) to explain the magnetic perturbations in the auroral zone. Theoretical models have been developed to examine the effect of these currents on the ionosphere. These models, in general, involve very extensive computer programs, and it is difficult to see how their very complicated boundary conditions and assumptions affect the relationships between the Birkeland currents and magnetic activity. In the present investigation, a simplified analysis is used to study the average behavior of the large-scale ionospheric current paths and to examine the interrelationships of various parameters. The relationship of the parameters of the current deposition regions to the magnetic indices is investigated along with the polar cap potential. Attention is given to the experimental values of coefficients, and relations between the Birkeland current densities, current intensities, currents, and the AL, AU, AE indices are discussed.

  4. Statistical study of auroral fragmentation into patches

    NASA Astrophysics Data System (ADS)

    Hashimoto, Ayumi; Shiokawa, Kazuo; Otsuka, Yuichi; Oyama, Shin-ichiro; Nozawa, Satonori; Hori, Tomoaki; Lester, Mark; Johnsen, Magnar Gullikstad

    2015-08-01

    The study of auroral dynamics is important when considering disturbances of the magnetosphere. Shiokawa et al. (2010, 2014) reported observations of finger-like auroral structures that cause auroral fragmentation. Those structures are probably produced by macroscopic instabilities in the magnetosphere, mainly of the Rayleigh-Taylor type. However, the statistical characteristics of these structures have not yet been investigated. Here based on observations by an all-sky imager at Tromsø (magnetic latitude = 67.1°N), Norway, over three winter seasons, we statistically analyzed the occurrence conditions of 14 large-scale finger-like structures that developed from large-scale auroral regions including arcs and 6 small-scale finger-like structures that developed in auroral patches. The large-scale structures were seen from midnight to dawn local time and usually appeared at the beginning of the substorm recovery phase, near the low-latitude boundary of the auroral region. The small-scale structures were primarily seen at dawn and mainly occurred in the late recovery phase of substorms. The sizes of these large- and small-scale structures mapped in the magnetospheric equatorial plane are usually larger than the gyroradius of 10 keV protons, indicating that the finger-like structures could be caused by magnetohydrodynamic instabilities. However, the scale of small structures is only twice the gyroradius of 10 keV protons, suggesting that finite Larmor radius effects may contribute to the formation of small-scale structures. The eastward propagation velocities of the structures are -40 to +200 m/s and are comparable with those of plasma drift velocities measured by the colocating Super Dual Auroral Radar Network radar.

  5. Auroral resonance line radiative transfer

    SciTech Connect

    Gladstone, G.R. )

    1992-02-01

    A model is developed for simulating the two-dimensional radiative transfer of resonance line emissions in auroras. The method of solution utilizes Fourier decomposition of the horizontal dependence in the intensity field so that the two-dimensional problem becomes a set of one-dimensional problems having different horizontal wavenumbers. The individual one-dimensional problems are solved for using a Feautrier-type solution of the differential-integral form of the radiative transfer equation. In the limit as the horizontal wavenumber becomes much larger than the local line-center extinction coefficient, the scattering integral becomes considerably simplified, and the final source function is evaluated in closed form. The two-dimensional aspects of the model are tested against results for nonresonance radiative transfer studies, and the resonance line part of the model is tested against results of existing plane-parallel resonance line radiative transfer codes. Finally, the model is used to simulate the intensity field of O{sub I} 1,304{angstrom} for hard and soft auroras of various Gaussian horizontal widths. The results demonstrate the importance of considering the effects of two-dimensional radiative transfer when analyzing auroral resonance line data.

  6. Polarisation of the auroral red line in the Earth's upper atmosphere: a review (Invited)

    NASA Astrophysics Data System (ADS)

    Lamy, H.; Barthelemy, M.; Lilensten, J.; Bommier, V.; Simon Wedlund, C.

    2013-12-01

    Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Polarimetry of auroral emission lines in the Earth's upper atmosphere has been overlooked for decades. However, the bright red auroral line (6300Å) produced by collisional impact with electrons precipitating along magnetic field lines is a good candidate to search for polarisation. This problem was investigated recently with observations obtained by Lilensten et al (2008), Barthélemy et al (2011) and Lilensten et al (2013) with a photopolarimeter. Analysis of the data indicates that the red auroral emission line is polarised at a level of a few percent. The results are compared to theoretical predictions of Bommier et al (2011) that were obtained for a collimated beam. The comparison suggests the existence of depolarization processes whose origin will be discussed. A new dedicated spectropolarimeter currently under development will also be presented. This instrument will cover the optical spectrum from approximately 400 to 700 nm providing simultaneously the polarisation of the red line and of other interesting auroral emission lines such as N2+ 1NG (4278Å), other N2 bands, etc... The importance of these polarisation measurements in the context of upper atmosphere modelling and geomagnetic activity will be discussed. Lilensten, J. et al, Polarization in aurorae: A new dimension for space environments studies, Geophys. Res. Lett., 26, 269, 2008 Barthélemy M. et al, Polarisation in the auroral red line during coordinated EISCAT Svalbard Radar/optical experiments, Annales Geophysicae, Volume 29, Issue 6, 2011, 1101-1112, 2011. Bommier V. et al, The Theoretical Impact Polarization of the O I 6300 Å Red Line of Earth Auroræ, Annales Geophysicae, Volume 29, Issue 1, 2011, 71-79, 2011 Lilensten, J. et al, The thermospheric auroral red line polarization: confirmation of detection and first quantitative analysis, Journal of Space Weather and Space

  7. Solar Array and Auroral Charging Studies of DMSP Spacecraft

    NASA Technical Reports Server (NTRS)

    Matias, Kelwin

    2013-01-01

    The SSJ electrostatic analyzers and the SSIES plasma instruments on the DMSP spacecraft in low Earth polar orbit can be used to conduct case studies of auroral and solar array charging. We will use a program written in the Interactive Data Language (IDL) to evaluate questionable charging events in the SSJ records by comparing charging signatures in SSJ and SSIES data. In addition, we will assemble a number of case studies of solar array charging showing the signatures from the SSJ data and compare to the SSIES charging signatures. In addition we will use Satellite Tool Kit (STK) to propagate orbits, obtain solar intensity, and use to verify onset of charging with sunrise.

  8. Variation of Jupiter's aurora observed by Hisaki/EXCEED: 2. Estimations of auroral parameters and magnetospheric dynamics

    NASA Astrophysics Data System (ADS)

    Tao, Chihiro; Kimura, Tomoki; Badman, Sarah V.; André, Nicolas; Tsuchiya, Fuminori; Murakami, Go; Yoshioka, Kazuo; Yoshikawa, Ichiro; Yamazaki, Atsushi; Fujimoto, Masaki

    2016-05-01

    Jupiter's auroral parameters are estimated from observations by a spectrometer EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) on board Japanese Aerospace Exploration Agency's Earth-orbiting planetary space telescope Hisaki. EXCEED provides continuous auroral spectra covering the wavelength range over 80-148 nm from the whole northern polar region. The auroral electron energy is estimated using a hydrocarbon color ratio adopted for the wavelength range of EXCEED, and the emission power in the long wavelength range 138.5-144.8 nm is used as an indicator of total emitted power before hydrocarbon absorption and auroral electron energy flux. The quasi-continuous observations by Hisaki provide the auroral electron parameters and their relation under different auroral activity levels. Short- (within < one planetary rotation) and long-term (> one planetary rotation) enhancements of auroral power accompany increases of the electron number flux rather than the electron energy variations. The relationships between the auroral electron energy (~70-400 keV) and flux (1026-1027/s, 0.08-0.9 μA/m2) estimated from the observations over a 40 day interval are in agreement with field-aligned acceleration theory when incorporating probable magnetospheric parameters. Applying the electron acceleration theory to each observation point, we explore the magnetospheric source plasma variation during these power-enhanced events. Possible scenarios to explain the derived variations are (i) an adiabatic variation of the magnetospheric plasma under a magnetospheric compression and/or plasma injection, and (ii) a change of the dominant auroral component from the main emission (main aurora) to the emission at the open-closed boundary.

  9. Quasi-Stationary Global Auroral Ionospheric Model: E-layer

    NASA Astrophysics Data System (ADS)

    Nikolaeva, Vera; Gordeev, Evgeny; Kotikov, Andrey; Makarova, Ludmila; Shirochkov, Aleksander

    2014-05-01

    E-layer Auroral Ionospheric Model (E-AIM) is developed to provide temporal and spatial density distribution of the main ionosphere neutral species (NO, N(4S),N(2D)), and ions (N2+, NO+,O2+,O+) in the altitude range from 90 to 150 km. NRLMSISE-00 model [Picone et al., JGR 2003] is used for neutral atmosphere content and temperature determination, that is the input for the E-AIM model. The E-AIM model based on chemical equilibrium state in E-layer that reaches in chemical reactions between ionospheric species considering solar radiation ionization source, superposed with sporadic precipitation of magnetospheric electrons. The chemical equilibrium state in each location under specific solar and geomagnetic activity conditions reaches during numerical solution of the continuity equations for the neutrals and ions using the high-performance Gear method [Gear, 1971] for ordinary differential equation (ODE) systems. Applying the Gear method for solving stiff ODE system strongly reduce the computation time and machine resources comparing to widely used methods and provide an opportunity to calculate the global spatial E-layer ion content distribution. In contrast to the mid-latitude ionosphere, structure and dynamics of the auroral zone ionosphere (φ ≡ 60-75° MLat) associated not only with shortwave solar radiation. Precipitating magnetospheric particle flux is the most important ionization source and is the main cause of E-layer disturbances. Precipitated electrons with initial energies of 1 - 30 keV influence the auroral ionosphere E-layer. E-AIM model can estimate ionization rate corresponds to auroral electron precipitation in two different ways: 1. with direct electron flux satellite data; 2. with differential energy spectrum reconstructed from OVATION-Prime empirical model [Newell, JGR 2009] average values, that allows to estimate ionosphere ion content for any time and location in the auroral zone. Comparison of E-AIM results with direct ionospheric observations

  10. Statistical study of auroral fragmentation into patches

    NASA Astrophysics Data System (ADS)

    Hashimoto, A.; Shiokawa, K.; Otsuka, Y.; Oyama, S. I.; Nozawa, S.; Hori, T.; Lester, M.

    2014-12-01

    Auroral complex shapes are formed through the connection of the ionosphere and magnetosphere by the geomagnetic field lines, projecting disturbances in the magnetosphere onto the ionosphere through auroral particles. Thus, the study of auroral dynamics is important for the understanding of magnetospheric disturbances. Shiokawa et al. [JGR, 2010] reported observations of small-scale finger-like auroral structures which appeared on the west side of auroral patches, at Gillam (GLAT=65.5°N), Canada, suggesting a pressure-driven plasma instability in the magnetosphere. However, statistical characteristics of this phenomenon have not been investigated yet. Using an all-sky imager at Tromsoe (MLAT=67.1°N), Norway, from January 2009 to November 2012, we made a statistical analysis of the occurrence conditions of 19 events of auroral structures that seemed to be caused by pressure-driven instability. We found 14 large-scale finger-like structures, developed from auroral arcs, and 6 small-scale finger-like structures which appeared in auroral patches. The large-scale structures were seen from midnight to dawn MLT and small-scale structures were seen mainly at dawn. Large and small-scale structures tend to appear at the beginning and late recovery phase of substorms, respectively. Their scale sizes are larger than the gyro-radius of the ions in the magnetospheric equatorial plane, indicating that the finger-like structures are caused by MHD instabilities. However, the size of the small-scale structures is roughly two times that of the gyro-radius of the ions, suggesting that the ion finite Larmor radius effects may play a role in the shape of small-scale structures [Hiraki and Sakaguchi, 2010]. Additionally, the eastward propagation speeds of the finger-like structures are slower than the typical midnight auroral drift speed, indicating that the low-energy plasma may be the source of these structures. These results could contradict the idea that the high-energy particles

  11. The Auroral Zone: A citizen science project to classify auroral imaging data

    NASA Astrophysics Data System (ADS)

    Chaddock, D.; Spanswick, E.; Gillies, D. M.; Quinney, A.; Donovan, E.; Murray, M. S.

    2015-12-01

    Currently, over 40 million images of the aurora have been recorded by University of Calgary all-sky imagers. Analysis of these images is an important and crucial step in the advancement of auroral physics. The number of images waiting to be analyzed is expected to increase dramatically with the introduction of TREx (Transition Region Explorer), a new high resolution imaging network set to be deployed in late 2016. In order to classify large amounts of images in a short period of time, we have designed a citizen science project aimed at engaging the general public in auroral science, called "The Auroral Zone". This project facilitates a symbiotic relationship between the scientific community and the general public. Using the data from this website, a large database of classified auroral images will be created and then used for future analysis by the scientific community. In exchange, the general public can learn about the aurora and contribute to auroral physics in a tangible way. The ultimate aim of this project is to create an ever expanding database of all-sky images classified by arc type (i.e. single arc, diffuse aurora, multiple arc, etc.) and filtered for adverse viewing conditions (i.e. snow, rain, light pollution, etc). We aim to introduce "The Auroral Zone" into the school systems to interest young scientists in the spectacular natural phenomenon that defines the Canadian North. "The Auroral Zone" is a collaborative project between the University of Calgary, Canadian Space Agency, AuroraMAX, and Aurorasaurus.

  12. Evaluating auroral processes within a magnotospheric model. Final report

    SciTech Connect

    Lyons, L.R.

    1989-01-01

    A summary of the research performed is included. Topics covered include magnetospheric model; association between discrete auroras and ion precipitation from the tail current sheet; auroral arc scale sizes and structures; polar cap size variation; low-altitude auroral boundary; auroral wave-particle interactions; thermospheric interactions; and the neutral wind flywheel.

  13. Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere. Final Report

    SciTech Connect

    Chiu, Y.T.; Gorney, D.J.

    1982-01-01

    Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector, morning and dayside auroras, auroral plasma formation, electrodynamic coupling with the thermosphere, and auroral electron interaction with the atmosphere.

  14. Modelling of auroral electrodynamical processes: Magnetosphere to mesosphere

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Gorney, D. J.; Kishi, A. M.; Newman, A. L.; Schulz, M.; Walterscheid, R. L.; CORNWALL; Prasad, S. S.

    1982-01-01

    Research conducted on auroral electrodynamic coupling between the magnetosphere and ionosphere-atmosphere in support of the development of a global scale kinetic plasma theory is reviewed. Topics covered include electric potential structure in the evening sector; morning and dayside auroras; auroral plasma formation; electrodynamic coupling with the thermosphere; and auroral electron interaction with the atmosphere.

  15. Cluster Observations of the Auroral Acceleration Region

    NASA Astrophysics Data System (ADS)

    Sadeghi, S.; Marklund, G.; Karlsson, R.; Lindqvist, P.; Li, B.; Nilsson, H.; Marghitu, O.; Fazakerley, A. N.; Lucek, E. A.

    2011-12-01

    We present results from Cluster satellite multi-point event studies from the auroral acceleration region (AAR). Electric potential structures associated with inverted-V aurora are investigated using electric field, magnetic field, ion and electron data from the Cluster spacecraft, crossing the auroral acceleration region (AAR) at different altitudes above the auroral oval. The spatial and temporal development of the acceleration structures is studied, given the magnetic conjunction opportunity and the short time-difference between the Cluster spacecraft crossings. The configuration allowed for estimating the characteristic times of development for the structures and estimating the parallel electric field and potential drop. For one of the negative potential structures, a growth time of 40 s and stability for more than one minute was observed and an average parallel electric field was estimated (~ 0.56 mV/m, between 1.13 and 1.3 RE of altitude).

  16. Adam Paulsen, a Pioneer in Auroral Research

    NASA Astrophysics Data System (ADS)

    Jørgensen, Torben S.; Rasmussen, Ole

    2006-02-01

    The 20 to 30 years following the first International Polar Year in 1882-1883 was a period of quickly advancing knowledge and understanding of auroral phenomena. This was the time when hypotheses of aurora being due to, for example, reflections of fires from the interior of the Earth or sunlight from ice particles were abandoned and replaced by the mechanism of precipitating electrons. One of the auroral researchers at that time was the Dane Adam Frederik Wivet Paulsen (1833-1907). However, when reading literature about auroral history, his ideas and work do not seem to have attracted much interest outside his own and neighboring countries. For example, in his sweeping historical account Majestic Lights: The Aurora in Science, History, and the Arts [1980], author Robert Eather only referred to Paulsen in a couple of lines.

  17. Global auroral responses to magnetospheric compressions by shocks in the solar wind: Two case studies

    NASA Technical Reports Server (NTRS)

    Craven, J. D.; Frank, L. A.; Russell, C. T.; Smith, E. J.; Lepping, R. P.

    1985-01-01

    The global auroral responses to shocks in the solar wind at Earth were studied. The z-component of the interplanetary magnetic field, Bz, is negative ahead and behind the first shock and positive for the second case. A sudden-commencement geomagnetic storm develops in each case, with maximum D sub st 190 nT. An immediate auroral response is detected at all longitudes around the auroral oval, in which auroral luminosities increase by a factor of 2 to 3 with the first samples after each sudden commencement. The time delay in obtaining the first sample varies with local time from approx. 1 to 18 mins. No other significant variations in the aurora are associated with the immediate response. Beginning approx. 30 mins after each sudden commencement, the aurora becomes active and displays significant variations in its luminosity and spatial distribution. For Bz 0 an intense substorm develops. A sun-aligned transpolar arc forms when Bz 0, appearing first at local midnight as a polar arc and then lengthening sunward from the auroral oval across the polar cap to noon at an average speed of approx. 1 km/sec.

  18. Very low frequency waves stimulated by an electron accelerator in the auroral ionosphere

    NASA Technical Reports Server (NTRS)

    Holtet, J. A.; Pran, B. K.; Egeland, A.; Grandal, B.; Jacobsen, T. A.; Maehlum, B. N.; Troim, J.

    1981-01-01

    The sounding rocket, Polar 5, carrying a 10 keV electron accelerator in a mother-daughter configuration and other diagnostic instruments, was launched into a slightly disturbed ionosphere with weak auroral activity on February 1, 1976 from Northern Norway to study VLF wave phenomena. The rocket trajectory crossed two auroral regions: one, between 86 and 111 s flight time, and a secondary region between 230 and 330 s. The daughter, carrying the accelerator, was separated axially from the mother in a forward direction at an altitude of 90 km. The VLF experiment, carried by the mother payload, recorded both electromagnetic and electrostatic waves. The receiving antenna was an electric dipole, 0.3 m tip-to-tip, oriented 90 degrees to the rocket spin axis. The onboard particle detector recorded increased electron fluxes in the two auroral regions. A double peaked structure was observed in the fluxes of 4-5 and 12-27 keV electrons within the northern auroral form. The number density of thermal plasma varied during the flight, with maximum density within the main auroral region. To the north of this aurora a slow, steady decrease in the density was observed, with no enhancement in the region of the second aurora.

  19. Precipitating Electron Population Inversion from Auroral Optical Data during the MICA Rocket Launch

    NASA Astrophysics Data System (ADS)

    Ahrns, J.; Hampton, D. L.; Stenbaek-Nielsen, H.; Michell, R. G.; Samara, M.; Powell, S.; Lynch, K. A.; Fernandes, P. A.; Lessard, M.

    2012-12-01

    The MICA (Magnetosphere-Ionosphere Coupling in the Alfvèn Resonator) sounding rocket was launched from Poker Flat, AK on Feb 19, 2012, into a series of discrete auroral arcs immediately following auroral breakup. We operated a set of ground-based optical imagers in support of the launch which captured the event, including more than an hour of auroral activity in the eventual rocket trajectory prior to launch at a variety of temporal (~1 second cadence to video frame rate) and spatial (all-sky to sub-kilometer) resolutions and in several spectral emission lines. Our imagers were located at Poker Flat, Fort Yukon, and Venetie AK (the last of which viewed the auroral conjugate of the rocket at magnetic zenith with sub-kilometer resolution) which allows a 3-dimensional reconstruction of certain auroral features from the optical data. We use this data, along with an electron transport model, to estimate the precipitating electron population and its effect on the background plasma to characterize the energy input prior to and during the rocket flight.

  20. Building Technologies Program Key Activities

    SciTech Connect

    2011-12-15

    The Building Technologies Program (BTP) employs a balanced approach to making buildings more energy efficient. The three pillars of our program, research and development (R&D), market stimulation, and building and equipment standards, help meet our strategic vision.

  1. Origin of auroral electric potential structures

    NASA Astrophysics Data System (ADS)

    Chiu, Y. T.

    Available observational data and theoretical models of the formation of auroral electric potential structures are reviewed. It is shown that the principle of arc formation in the aurora can also be applied to other geomagnetic configurations, in order to construct a comprehensive theory of discrete auroral arcs. According to the theory, the completion of the field-aligned current circuit in the aurora can lead to downward parallel electric fields in the return current from the central region of discrete arc potential. It is pointed out that evidence for downward parallel electric field signatures has been collected within the last year.

  2. A real-time hybrid aurora alert system: Combining citizen science reports with an auroral oval model

    NASA Astrophysics Data System (ADS)

    Case, N. A.; Kingman, D.; MacDonald, E. A.

    2016-06-01

    Accurately predicting when, and from where, an aurora will be visible is particularly difficult, yet it is a service much desired by the general public. Several aurora alert services exist that attempt to provide such predictions but are, generally, based upon fairly coarse estimates of auroral activity (e.g., Kp or Dst). Additionally, these services are not able to account for a potential observer's local conditions (such as cloud cover or level of darkness). Aurorasaurus, however, combines data from the well-used, solar wind-driven, OVATION Prime auroral oval model with real-time observational data provided by a global network of citizen scientists. This system is designed to provide more accurate and localized alerts for auroral visibility than currently available. Early results are promising and show that over 100,000 auroral visibility alerts have been issued, including nearly 200 highly localized alerts, to over 2000 users located right across the globe.

  3. Stratospheric benzene and hydrocarbon aerosols in Saturn's auroral regions

    NASA Astrophysics Data System (ADS)

    Guerlet, S.; Fouchet, T.; Vinatier, S.; Simon, A. A.; Dartois, E.; Spiga, A.

    2015-10-01

    Saturn's polar upper atmosphere exhibits significant auroral activity, however, its impact on stratospheric chemistry (i.e.the production of benzene and heavier hydrocarbons) and thermal structure is poorly documented. Here we report on the first measurement of benzene column abundance in Saturn's polar stratosphere, together with the first detection of spectral sig- natures of the polar haze in the thermal infrared, based on limb measurements from the Composite Infrared Spectrometer (CIRS) on board Cassini. We then evaluate the radiative impact of the polar haze.

  4. Drifts of auroral structures and magnetospheric electric fields

    SciTech Connect

    Nakamura, Rumi; Oguti, Takasi )

    1987-10-01

    Drifts of pulsating auroral patches and discrete auroral arc fragments are analyzed on the basis of all-sky TV observations of auroras. The drifts of auroral structures in this study correspond on a gross scale with other measurements of magnetospheric convection. The result strongly suggests that not only auroral patches but also arc fragments, when detached from the main body of the discrete aurora, drift owing to the magnetospheric electric fields. The measurement of the drifts of auroral structures could possibly provide us with a convenient and accurate method to estimate the magnetospheric electric fields.

  5. Cluster multi-spacecraft observations of electron and ion holes in the Auroral Acceleration Region

    NASA Astrophysics Data System (ADS)

    Fazakerley, A. N.; Pickett, J. S.; Berthomier, M.; Mutel, R. L.; Masson, A.; Forsyth, C.; Owen, C. J.; Khotyaintsev, Y. V.; Andre, M.; Carr, C.

    2013-12-01

    In spring 2013, the Cluster spacecraft have visited the Auroral Acceleration Region (AAR) for the second and final time. The spacecraft constellation was arranged to produce very small separation magnetic field aligned conjunctions (~10s km) between C3 and C4, with C1 relatively nearby. The goal was to allow study of electron and ion holes, including their propagation between C3 and C4, and their roles in generating waves that may be observed locally and also at C1. Detailed planning work has tried to maximize the opportunities to use the Cluster payload effectively during these conjunctions, but the presence of auroral activity during the relatively few AAR passes cannot be guaranteed in advance. The dataset may also be valuable for other aspects of auroral science, as data is collected throughout the AAR crossings, not only at the conjunctions. We intend to present first results from this campaign.

  6. Cluster multi-spacecraft observations of electron and ion holes in the Auroral Acceleration Region

    NASA Astrophysics Data System (ADS)

    Fazakerley, Andrew; Pickett, Jolene; Berthomier, Matthieu; Mutel, Robert; Masson, Arnaud; Forsyth, Colin; Owen, Christopher J.; Khotyaintsev, Yuri; Andre, Mats; Carr, Chris

    2014-05-01

    In spring 2013, the Cluster spacecraft visited the Auroral Acceleration Region (AAR) for the second and final time. The spacecraft constellation was arranged to produce very small separation magnetic field aligned conjunctions (~10s km) between C3 and C4, with C1 relatively nearby. The goal was to allow study of electron and ion holes, including their propagation between C3 and C4, and their roles in generating waves that may be observed locally and also at C1. Detailed planning work has tried to maximize the opportunities to use the Cluster payload effectively during these conjunctions, but the presence of auroral activity during the relatively few AAR passes could be guaranteed in advance. The dataset may also be valuable for other aspects of auroral science, as data is collected throughout the AAR crossings, not only at the conjunctions. We intend to present first results from this campaign.

  7. Jovian longitudinal asymmetry in Io-related and Europa-related auroral hot spots

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.; Chamberlain, J. W.

    1979-01-01

    Auroral emissions generated by the Jovian moons Io and Europa, originating at the foot of the magnetic flux tubes of the satellites, may be largely limited to longitudes where the planet's ionospheric conductivity is enhanced. The enhanced conductivity is produced by trapped energetic electrons that drift into the Jovian atmosphere in regions where the planet's magnetic field is anomalously weak. The most active auroral hot-spot emissions lie in a sector of the northern hemisphere defined by decametric radio emission. Weaker auroral hot spots are found in the southern hemisphere along a magnetic conjugate trace. The brightness and the longitude of the Jovian hot spots predicted in this paper are in agreement with observations reported by Atreya et al. (1977).

  8. Auroral Radio Emission Direction of Arrival Studies of Simultaneous Medium Frequency Burst and Auroral Hiss

    NASA Astrophysics Data System (ADS)

    Broughton, M.; Labelle, J. W.

    2010-12-01

    The auroral zone is the source of multiple kinds of radio emissions that can be observed on the ground. The study of radio emissions offers a way to remotely sense space plasma processes and, in the case of auroral emissions, to use the auroral ionosphere as a large-scale plasma physics laboratory. Medium frequency (MF) burst is an impulsive radio emission at 1.5-4.5 MHz observed on the ground. Its generation mechanism is unknown, and it is often associated with the onset of substorms. Auroral hiss is an impulsive emission observed on the ground at frequencies up to 1 MHz and is also associated with substorm onset. LaBelle et al. [1997] reported a temporal relationship between MF burst and auroral hiss. Multiple impulses of both MF burst and auroral hiss occurred simultaneously over a time period that in certain cases lasted tens of minutes. While the temporal relationship on the timescale of seconds is well established, the spatial relationship between MF burst and auroral hiss has yet to be investigated. Dartmouth College currently operates a broadband (0-5 MHz) four-element radio interferometer at Toolik Field Station in Alaska (68° 38' N, 149° 36' W, 68.5° magnetic latitude) in order to study the direction of arrival (DOA) of radio emissions. Since the antenna spacing is 50 meters, the interferometer is optimized for DOA measurements of MF bursts. However, in certain cases, it can provide the DOA for the high-frequency portion of impulsive auroral hiss. We present two case studies that represent the first simultaneous DOA measurements of impulsive auroral hiss and MF burst. On March 4, 2010, the DOA of MF burst was predominantly from 30 degrees south of east, an observation consistent with the statistical work performed by Bunch et al. [2009]. Simultaneous DOA measurements of the high-frequency portion of auroral hiss also showed the DOA as approximately 30 degrees south of east but with greater scatter in the data. The second case study, which involved an

  9. Equatorward and poleward expansion of the auroras during auroral substorms

    NASA Technical Reports Server (NTRS)

    Nakamura, Rumi; Oguti, Takasi; Yamamoto, Tatsundo; Kokubun, Susumu

    1993-01-01

    The formation of the auroral bulge is investigated on the basis of all-sky TV auroral data with high spatial and temporal resolution. Ways in which the discrete auroral structures within the poleward expanding bulge develop systematically toward the west, the east, and also equatorward from a localized breakup region are shown. Auroral structure at the western end of the bulge (a surge) develops with clockwise rotation as viewed along the magnetic field direction. At the eastern part of the bulge, thin auroral features propagate eastward from the breakup region. Around the central meridian of the bulge, auroral features expand equatorward and become north-south aligned (the N-S aurora). The N-S aurora and the eastward propagating aurora develop into diffuse and pulsating aurora after the expansion. It is suggested that these discrete auroral structures in the bulge develop along the plasma streamlines in a localized distorted two-cell equipotential distribution.

  10. Magneto-gravity waves caused by auroral electrojets instability

    NASA Astrophysics Data System (ADS)

    Barkhatov, Nikolay; Barkhatova, Oksana; Grigor'ev, Gennadiy

    2010-05-01

    (MOF) on the specified traces correlation research is carried out. Time shifts between index AE and MOF for considered traces at which high correlation is marked are determined. These time shifts answer times necessary for magneto-gravity waves propagation from auroral region to radio-waves reflection points. Among received values of time shifts cases (5-10 min) answering to increased velocity (2000 - 5000 m/s) of disturbance propagation in comparison with usual AGW velocities for investigated paths are marked. Comparison of dynamic spectrum of index AE variations and MOF on specified traces for cases of their increased correlation for 5-10 min shifts shows similar spectrum features. It confirms an opportunity of auroral disturbances propagation to low latitudes with velocity higher than AGW. Such cases can be connected with MGW propagation. Similarity of spectrograms of index AE disturbances with spectrograms of magnetic field horizontal component disturbances at three ground stations located close to reflection points of paths Inskip - Rostov-on-Don, Cyprus - Rostov-on-Don is founded. It also proves MGW existence and their propagation from auroral regions to low latitudes. The analysis of the dispersive equations for fast «+ mode» and slower «- mode» MGW has allowed to execute an analytical estimation of MGW frequencies and velocities for conditions of a real ionosphere. As a result MGW frequencies (1-2)•10^(-4) Hz and velocities about 6500 m/s are received which are in accord with experimentally founded values. We are grateful to Uryadov V.P., Vertogradov G.G. and Vertogradov V.G. for ionosphere oblique sounding data granting. Work is executed at partial support under grants of the RFBR 08-05-12051-OBR and 09-05-00495, and also program Ministry of Education and Science «Development of higher school scientific potential (2009-2010, project N 1623)».

  11. Numerical and laboratory simulations of auroral acceleration

    SciTech Connect

    Gunell, H.; De Keyser, J.; Mann, I.

    2013-10-15

    The existence of parallel electric fields is an essential ingredient of auroral physics, leading to the acceleration of particles that give rise to the auroral displays. An auroral flux tube is modelled using electrostatic Vlasov simulations, and the results are compared to simulations of a proposed laboratory device that is meant for studies of the plasma physical processes that occur on auroral field lines. The hot magnetospheric plasma is represented by a gas discharge plasma source in the laboratory device, and the cold plasma mimicking the ionospheric plasma is generated by a Q-machine source. In both systems, double layers form with plasma density gradients concentrated on their high potential sides. The systems differ regarding the properties of ion acoustic waves that are heavily damped in the magnetosphere, where the ion population is hot, but weakly damped in the laboratory, where the discharge ions are cold. Ion waves are excited by the ion beam that is created by acceleration in the double layer in both systems. The efficiency of this beam-plasma interaction depends on the acceleration voltage. For voltages where the interaction is less efficient, the laboratory experiment is more space-like.

  12. Particle simulation of auroral double layers

    NASA Technical Reports Server (NTRS)

    Smith, Bruce L.; Okuda, Hideo

    1987-01-01

    Work on the simulation of auroral double layers (DLs) with realistic particle-in-cell models is presented. An early model simulated weak DLs formed in a self-consistent circuit but under conditions subject to the ion-acoustic instability. Recent work has focused on strong DLs formed when currentless jets are injected into a dipole magnetic field.

  13. Stratospheric benzene and hydrocarbon aerosols detected in Saturn's auroral regions

    NASA Astrophysics Data System (ADS)

    Guerlet, S.; Fouchet, T.; Vinatier, S.; Simon, A. A.; Dartois, E.; Spiga, A.

    2015-08-01

    Context. Saturn's polar upper atmosphere exhibits significant auroral activity; however, its impact on stratospheric chemistry (i.e. the production of benzene and heavier hydrocarbons) and thermal structure remains poorly documented. Aims: We aim to bring new constraints on the benzene distribution in Saturn's stratosphere, to characterize polar aerosols (their vertical distribution, composition, thermal infrared optical properties), and to quantify the aerosols' radiative impact on the thermal structure. Methods: Infrared spectra acquired by the Composite Infrared Spectrometer (CIRS) on board Cassini in limb viewing geometry are analysed to derive benzene column abundances and aerosol opacity profiles over the 3 to 0.1 mbar pressure range. The spectral dependency of the haze opacity is assessed in the ranges 680-900 and 1360-1440 cm-1. Then, a radiative climate model is used to compute equilibrium temperature profiles, with and without haze, given the haze properties derived from CIRS measurements. Results: On Saturn's auroral region (80°S), benzene is found to be slightly enhanced compared to its equatorial and mid-latitude values. This contrasts with the Moses & Greathouse (2005, J. Geophys. Res., 110, 9007) photochemical model, which predicts a benzene abundance 50 times lower at 80°S than at the equator. This advocates for the inclusion of ion-related reactions in Saturn's chemical models. The polar stratosphere is also enriched in aerosols, with spectral signatures consistent with vibration modes assigned to aromatic and aliphatic hydrocarbons, and presenting similarities with the signatures observed in Titan's stratosphere. The aerosol mass loading at 80°S is estimated to be 1-4 × 10-5 g cm-2, an order of magnitude less than on Jupiter, which is consistent with the order of magnitude weaker auroral power at Saturn. We estimate that this polar haze warms the middle stratosphere by 6 K in summer and cools the upper stratosphere by 5 K in winter. Hence

  14. In situ observations of medium frequency auroral radio emissions

    NASA Astrophysics Data System (ADS)

    Broughton, M.; Labelle, J. W.; Pfaff, R. F.; Parrot, M.; Yan, X.; Burchill, J. K.

    2013-12-01

    The auroral ionosphere is a region rich with plasma waves that can be studied both in space and on the ground. These waves may mediate energy exchange between particle populations and provide information about the local plasma properties and boundaries. Auroral medium frequency (MF) burst is an impulsive radio emission observed at ground-level from 1.3-4.5 MHz that is associated with local substorm onset. There have been two recent reports of impulsive, broadband, MF waves at high latitudes. Burchill and Pfaff [2005] reported observations from the FAST satellite of impulsive, broadband, MF and low frequency (LF) radio waves. Using data from the DEMETER satellite, Parrot et al. [2009] surveyed MF waves caused by lightning. This study did show a high-latitude population of MF waves. We investigate whether the waves observed by these two satellites are related to auroral MF burst. Using FAST satellite burst mode electric field data from high-latitude (> 60 degrees magnetic), low-altitude (< 1000 km) intervals of moderate to large geomagnetic activity (Kp > 3) from 1996-2002, we have found forty-four examples of impulsive MF waves, all of which are associated with impulsive LF waves. Although MF burst and the waves observed by FAST have similar spectral signatures, they have different magnetic local time dependencies, which suggests that they may be unrelated. A study of MF waves observed at high latitude by DEMETER is ongoing. In situ observations of MF burst could provide crucial information about this heretofore unexplained natural radio emission.

  15. Evolution of auroral acceleration region field-aligned current systems, plasma, and potentials observed by Cluster during substorms

    NASA Astrophysics Data System (ADS)

    Hull, A. J.; Chaston, C. C.; Fillingim, M. O.; Frey, H. U.; Goldstein, M. L.; Bonnell, J. W.; Mozer, F.

    2015-12-01

    The auroral acceleration region is an integral link in the chain of events that transpire during substorms, and the currents, plasma and electric fields undergo significant changes driven by complex dynamical processes deep in the magnetotail. The acceleration processes that occur therein accelerate and heat the plasma that ultimately leads to some of the most intense global substorm auroral displays. Though this region has garnered considerable attention, the temporal evolution of field-aligned current systems, associated acceleration processes, and resultant changes in the plasma constituents that occur during key stages of substorm development remain unclear. In this study we present a survey of Cluster traversals within and just above the auroral acceleration region (≤3 Re altitude) during substorms. Particular emphasis is on the spatial morphology and developmental sequence of auroral acceleration current systems, potentials and plasma constituents, with the aim of identifying controlling factors, and assessing auroral emmission consequences. Exploiting multi-point measurements from Cluster in combination with auroral imaging, we reveal the injection powered, Alfvenic nature of both the substorm onset and expansion of auroral particle acceleration. We show evidence that indicates substorm onsets are characterized by the gross-intensification and filamentation/striation of pre-existing large-scale current systems to smaller/dispersive scale Alfven waves. Such an evolutionary sequence has been suggested in theoretical models or single spacecraft data, but has not been demonstrated or characterized in multispacecraft observations until now. It is also shown how the Alfvenic variations over time may dissipate to form large-scale inverted-V structures characteristic of the quasi-static aurora. These findings suggest that, in addition to playing active roles in driving substorm aurora, inverted-V and Alfvenic acceleration processes are causally linked. Key

  16. Auroral ultraviolet darkening on the outer planets

    SciTech Connect

    Pryor, W.R.

    1989-01-01

    The Voyager 2 Photopolarimeter Subsystem (PPS) has made photometric observations of Jupiter at 2400 A and photometric and polarimetric observations of Saturn and Uranus at 2650 A. At these wavelengths the instrument is observing each planet's stratosphere and upper troposphere. The most striking features are that both poles of Jupiter and the observed northern pole of Saturn are very dark, while Uranus has a uniformly bright appearance. All three planets show evidence for a stratospheric haze. Simple vertically homogeneous multiple scattering models are used to characterize these stratospheric hazes. Aurores occur at high latitudes on Jupiter and Saturn and at low latitudes on Uranus. The asymmetric polar darkening on Jupiter seen by PPS is roughly matched by the asymmetry in the auroral zones. Historical data suggest that the haze asymmetry is persistent. The dark north polar cap seen by PPS at Saturn is small and close to the pole, which corresponds to the small auroral zone close to the pole. A model is examined which attributes the darkening to auroral bombardment initiating methane chemistry that makes dark hydrocarbon particles. Possible chemical pathways are discussed, and mass balance calculations are presented for Jupiter, Saturn, and Uranus. The model is quantitatively plausible for Jupiter and Saturn. The lack of localized darkening on Uranus can be explained in this model by noting that weak vertical mixing and methane condensation near the 1-bar level lead to negligible methane abundances at auroral altitudes. The auroras must reach the methane for dark material to form. The thin haze that is seen on Uranus is ascribed to photochemical processes. Voyager 2 will reach Neptune this year. Ground-based observers have reported vigorous vertical mixing and large amounts of stratospheric methane there.

  17. Synoptical Auroral Ovals: A Comparison study with TIMED/GUVI Observations

    NASA Astrophysics Data System (ADS)

    Liou, K.; Paxton, L.; Zhang, Y.

    2007-12-01

    Whether the aurora Australis is a mirror image of its northern hemispheric counterpart is a question that auroral physicists have been wanting to answer. Owing to geophysical constraints, especially the large offset between the location of the southern magnetic and southern geographic poles, there is a paucity of information about the aurora Australis. Comparisons of some instantansous global-scale northern and southern auroras acquired conjugately by Polar and IMAGE spacecraft recently have shown mixed results. In this study, we present data from a different source to provide insight into the global morphology and behavior of the auroral oval. Approximately 20,000 Earth's disk FUV images acquired from the Global Ultraviolet Imager (GUVI) on-board NASA's Thermosphere, Ionosphere, Mesosphere, Energetics and Dynamics (TIMED) satellite between February 2002 and February 2006 are processed and analyzed. Synoptic auroral distributions for the northern and southern ovals are derived. Our study result reveals that the statistical oval is nearly hemispherically symmetric (within ±80%). Several known features in the morphology of the aurora Borealis are also observed in the Southern Hemisphere: For instance, the auroral midday gap and the premidnight maximum. The hemispherical symmetry of the auroras deteriorates as the partition of solar illumination in the two hemisphere polar region becomes asymmetric. It is estimated that the solar illumination effect accounts for up to ~50% of the hemispheric asymmetry. We found evidence that suggests that the aurora is suppressed under sunlit conditions in the South just as it is in the North. We also found that the auroral energy flux increases monotonically with the increase of the solar zenith angle. These results suggest that ionospheric conductivity plays an active role in regulating magnetospheric energy deposition in the auroral zone.

  18. PC Index as a Means to Monitor Processes in the Auroral Zone

    NASA Astrophysics Data System (ADS)

    Troshichev, Oleg

    2016-07-01

    The PC index was introduced [Troshichev et al., 1988] to characterize the polar cap magnetic activity generated by the geoeffective interplanetary electric field. Results of recent studies [Troshichev and Janzhura, 2012; Troshichev and Sormakov, 2015] are strongly indicative of PC index as a proxy of the solar wind energy that entered into the magnetosphere. The PC index in this charge can be successfully used to monitor processes in the auroral zone: 1. PC index well correlates with intensity of the Region 1 field-aligned currents measured by SWARM satellites on the auroral oval poleward boundary. As it is known, the R1 field-aligned currents flow into ionosphere in the morning auroral oval and flow out of ionosphere in the evening oval. The R1 FAC intensity and, correspondingly, the PC value increase in tandem before the substorm sudden onset. 2. PC-index can be taken as Input Parameter in Empirical Auroral Precipitation Model "OVATION-prime" [Newell, 2009] instead of the coupling function dØMP/dt. Use of the 1-min PC index in the modified OVATION-PC model provides the much better timing of the auroral precipitation with allowance for actual state of the magnetosphere. 3. There is a strong correspondence between the behavior of PC and development of magnetic disturbances in the auroral zone: the magnetic substorms are preceded by the PC index growth, the substorm onsets are commonly associated with a sharp increase in the PC growth rate, the substorm occurrence reaches the maximum when PC exceeds the threshold value ~ 1.5±0.5 mV/m, the linear correlation between the PC and AL values is typical of all classes of substorms, irrespective of their power. There regularities provide possibility to nowcast the substorm development.

  19. Low-altitude satellite measurements of pulsating auroral electrons

    NASA Astrophysics Data System (ADS)

    Samara, M.; Michell, R. G.; Redmon, R. J.

    2015-09-01

    We present observations from the Defense Meteorological Satellite Program and Reimei satellites, where common-volume high-resolution ground-based auroral imaging data are available. These satellite overpasses of ground-based all-sky imagers reveal the specific features of the electron populations responsible for different types of pulsating aurora modulations. The energies causing the pulsating aurora mostly range from 3 keV to 20 keV but can at times extend up to 30 keV. The secondary, low-energy electrons (<1 keV) are diminished from the precipitating distribution when there are strong temporal variations in auroral intensity. There are often persistent spatial structures present inside regions of pulsating aurora, and in these regions there are secondary electrons in the precipitating populations. The reduction of secondary electrons is consistent with the strongly temporally varying pulsating aurora being associated with field-aligned currents and hence parallel potential drops of up to 1 kV.

  20. Global Auroral Energy Deposition Derived from Polar UVI Images

    NASA Technical Reports Server (NTRS)

    Fillingim, M. O.; Brittnacher, M. J.; Elsen, R.; Parks, G. K.; Spann, J. F., Jr.; Germany, G. A.

    1997-01-01

    Quantitative measurement of the transfer of energy and momentum to the ionosphere from the solar wind is one of the main objectives of the ISTP program. Global measurement of auroral energy deposition derived from observations of the longer wavelength LBH band emissions made by the Ultraviolet Imager on the Polar spacecraft is one of the key elements in this satellite and ground-based instrument campaign. These "measurements" are inferred by combining information from consecutive images using different filters and have a time resolution on the average of three minutes and are made continuously over a 5 to 8 hour period during each 18 hour orbit of the Polar spacecraft. The energy deposition in the ionosphere from auroral electron precipitation augments are due to Joule heating associated with field aligned currents. Assuming conjugacy of energy deposition between the two hemispheres the total energy input to the ionosphere through electron precipitation can be determined at high time resolution. Previously, precipitating particle measurements along the tracks of low altitude satellites provided only local measurements and the global energy precipitation could be inferred through models but not directly measured. We use the UVI images for the entire month of January 1997 to estimate the global energy deposition at high time resolution. We also sort the energy deposition into sectors to find possible trends, for example, on the dayside and nightside, or the dawn and dusk sides.

  1. Studies of the auroral ionosphere with the MITHRAS

    NASA Astrophysics Data System (ADS)

    Foster, J. C.

    1986-06-01

    The extensive MITHRAS radar data set was the object of extensive analyses of the processes and characteristics of the auroral latitude ionosphere and thermosphere: (1) High-Latitude Electrodynamics: Ionospheric response to substorms at widely separated local times was investigated. (2) Ionospheric Plasma Transport: The effects of plasma convection on the formation of the midlatitude trough were studied utilizing the wide spatial field of view of the Millstone radar. (3) Convection Snapshots: Simultaneous data from spaced instruments were combined to produce snapshots of the polar and auroral convection pattern. (4) Comparisons with Models. (5) Data Bases Studies and Empirical Models: The extensive data set which resulted from the MITHRAS experimental program was incorporated into a multi-instrument, common format data base. (6) Azimuth Scan Experiments: Analysis of the complex data during MITHRAS azimuth scanning experiments resulted in the capability of mapping the convection electric field within the extended field of the radar. (7) Thermosphere and Exosphere: The diurnal variation of exospheric temperature over 30 degrees of latitude around Millstone Hill has been investigated using MITHRAS elevation scan data.

  2. The Auroral and Ground-Magnetic Response to Different Magnetotail Drivers

    NASA Astrophysics Data System (ADS)

    Rae, J.; Mann, I. R.; Murphy, K. R.; Walsh, A. P.; Milling, D. K.; Angelopoulos, V.

    2010-12-01

    Of critical importance to resolving the substorm problem is our understanding of the response of the ionosphere to a variety of magnetotail drivers. We present a series of case studies of the ionospheric response to substorm expansion phase onset and other auroral activations using both in-situ data from Cluster and THEMIS spacecraft and data from the combined networks of magnetometers in the North American sector, including those from CARISMA (www.carisma.ca), THEMIS ground-based observatory magnetic and optical network, and data from supporting arrays. We present details of magnetic disturbance diagnostics which may distinguish between tail drivers, including using ULF waves via the Automated Wavelet Estimation of Substorm Onset and Magnetic Events (AWEWSOME) technique and the creation of local auroral and polar electrojet indices. We then use an independently-derived list of nightside auroral activations in order to probe whether the location of the dominant electrojet signature and ULF wave activity can be used to determine the difference between magnetotail drivers. These analyses serve to highlight the importance of extensive magnetometer coverage in order to correctly identify and characterise the initiation and temporal variations of ionospheric electrodynamics during nightside auroral activations. We seek ground signatures that can distinguish between current systems due to various magnetotail drivers.

  3. Ground and satellite observations of auroral fragmentation into patches

    NASA Astrophysics Data System (ADS)

    Shiokawa, Kazuo; Nishi, Katsuki

    2016-07-01

    We review characteristic auroral fragmentation which is the process by which uniform aurora is broken into several fragments to form auroral patches, based on the all-sky camera observations at Tromsoe, Norway and THEMIS chain in Canada. The auroral fragmentation occurs as finger-like structures developing predominantly in meridional direction with speeds of several tens m/s and scale sizes of several tens kilometers without any shearing motion. These features suggest that pressure-driven instability in the balance between the earthward magnetic-tension force and the tailward pressure gradient force in the magnetosphere is the main driving force of the auroral fragmentation. Thus, these observations indicate that auroral fragmentation associated with pressure-driven instability is a process that creates auroral patches. Auroral fragmentation is seen from midnight to dawn local time and usually appears at the beginning of the substorm recovery phase, near the low latitude boundary of the auroral region. One example of plasma and magnetic field observations by the THEMIS satellite in the conjugate magnetosphere shows diamagnetic anti-phase variations of magnetic and plasma pressures with time scales of several to tens minutes associated with the auroral fragmentation. This observation also supports the idea of pressure-driven instability to cause the auroral fragmentation into patches.

  4. Comparing Auroral Far Ultraviolet Images and Coincident Ionosonde Observations of the Auroral E Region

    NASA Astrophysics Data System (ADS)

    Knight, H. K., Jr.; Galkin, I. A.; Reinisch, B. W.

    2014-12-01

    Comparisons are being made between auroral ionospheric E region parameters derived from two types of observations: satellite-based far ultraviolet (FUV) imagers and ground-based ionosondes. The FUV imagers are: 1) NASA's Thermosphere Ionosphere Mesosphere Energetics and Dynamics Global Ultraviolet Imager (TIMED/GUVI) and 2) DMSP's Special Sensor Ultraviolet Spectrographic Imager (SSUSI). The ionosondes are five high latitude Digisondes included in the Global Ionospheric Radio Observatory (GIRO) (Reinisch and Galkin, EPS, 2011). The purpose of the comparisons is to determine whether auroral FUV remote sensing algorithms that derive E region parameters from Lyman-Birge-Hopfield (LBH) emissions are biased in the presence of proton aurora. Earlier comparisons between FUV images and in situ auroral particle flux observations (e.g., Knight et al., JGR, 2012) indicate that proton aurora is much more efficient than electron aurora in producing LBH emission, and to be consistent with these findings the FUV-ionosonde comparisons would have to show that auroral FUV-derived NmE (maximum E region electron density) is biased high in the presence of proton precipitation. The advantage of making comparisons with Digisonde observations of the E region (as opposed to incoherent scatter radar) is that Digisondes remain in operation continuously over extended periods of time (i.e. years) and record observations every few minutes, making it possible to gather large numbers of FUV image-coincident observations for statistical studies. The subject of how to interpret auroral E region traces in ionograms has not been studied much up to now, however, and we are making progress in that area. We have found that a modified version of the rules from Piggott and Rawer, U.R.S.I. Handbook of Ionogram Interpretation and Reduction(1972) gives a large number of usable ionograms and good correlation with auroral FUV observations. The figure shows an example of an auroral FUV image with the locations

  5. Statistics of auroral hiss and relationship to auroral boundaries and upward current regions

    NASA Astrophysics Data System (ADS)

    Spasojevic, M.

    2016-08-01

    An 8 year database of VLF auroral hiss observations from South Pole station (invariant latitude of -74° with magnetic local time (MLT) = UT -3.5 h) is analyzed. There are three peaks in hiss occurrence as a function of MLT in the evening sector (19-23 MLT), afternoon sector (13-17 MLT), and morning sector (7-11 MLT). The geomagnetic and interplanetary magnetic field (IMF) drivers of hiss are examined in the three MLT sectors, and the results are interpreted using an empirical model of auroral boundaries and an empirical model of field-aligned current patterns. Auroral hiss on the dayside occurs when the auroral oval is centered near the latitude of the station, and in the afternoon sector higher disturbance levels are required. The afternoon sector favors positive By when Bz is positive and negative By when Bz is strongly negative, while the morning sector favors the complementary conditions. In each case the preference for hiss occurrence follows the pattern of upward field-aligned currents, and hiss is more likely in the configuration where the peak in the upward current is closer to the latitude of the station. IMF By does not play a role on the nightside where hiss is most likely to occur during moderately weak driving conditions as higher disturbance levels are expected to move the auroral oval and upward current systems to latitudes well equatorward of South Pole.

  6. Untangling the Space-Time Ambiguity of Auroral Emissions

    NASA Astrophysics Data System (ADS)

    Gjerloev, J. W.; Humberset, B.; Michell, R. G.; Samara, M.; Mann, I. R.

    2012-12-01

    In this paper we address the spatiotemporal characteristics of the magnetosphere-ionosphere (M-I) system as observed by an all-sky imager (ASI). We utilize 557.7 nm images obtained by a ground based ASI located under the dark ionosphere (~22 MLT) at Poker Flat, Alaska. The 19 min movie was recorded at 3.31 Hz during continuous moderately intense auroral activity driven by a southward IMF Bz of about -5 nT. We analyze this movie using a simple, yet robust, 2D FFT technique that allows us to determine the scale size dependent variability. When plotting the correlation pattern as a function of scale size and time separation we find a pattern with distinct regions of high and low correlation. Larger scale sizes are found to have longer duration. We interpret this remarkable result as indicative of a M-I system that uses repeatable solutions to transfer energy and momentum from the magnetosphere to the ionosphere. Our findings support the characteristics of the field-aligned currents as determined from multi-point satellite observations (ST-5, Gjerloev et al., Annales Geophysicae, 2011). Two different electromagnetic parameters, auroral emissions and field-aligned currents, display similar characteristics supporting our conclusion that this is indicative of a fundamental behavior of the M-I system.

  7. Electron density depletions in the nightside auroral zone

    NASA Technical Reports Server (NTRS)

    Persoon, A. M.; Gurnett, D. A.; Peterson, W. K.; Waite, J. H., Jr.; Burch, J. L.; Green, J. L.

    1988-01-01

    Dynamics Explorer 1 measurements are used to investigate regions of low electron density in the nightside auroral zone. Sharply defined regions of low electron density are found in auroral zone crossings from the predusk hours until the early morning hours at all radial distances up to at least 4.6 earth radii. Densities in the auroral cavity are shown to fall to values below 0.3/cu cm. Within the auroral cavity, electron-density-profile variations of a factor of 2 or more on spatial scales of tens of kilometers are found, and the electron plasma frequency to electron cyclotron frequency ratios are 0.02-0.4. The results suggest associations between the density depletions in the nightside auroral zone and auroral acceleration processes.

  8. Vehicle Technologies Program Educational Activities

    SciTech Connect

    2011-12-13

    Description of educational activities including: EcoCAR2: Plugging In to the Future, EcoCAR: The NeXt Challenge, Green Racing, Automotive X Prize, Graduate Technology Automotive Education (GATE), and Hydrogen Education.

  9. Auroral meridian scanning photometer calibration using Jupiter

    NASA Astrophysics Data System (ADS)

    Jackel, Brian J.; Unick, Craig; Creutzberg, Fokke; Baker, Greg; Davis, Eric; Donovan, Eric F.; Connors, Martin; Wilson, Cody; Little, Jarrett; Greffen, M.; McGuffin, Neil

    2016-10-01

    Observations of astronomical sources provide information that can significantly enhance the utility of auroral data for scientific studies. This report presents results obtained by using Jupiter for field cross calibration of four multispectral auroral meridian scanning photometers during the 2011-2015 Northern Hemisphere winters. Seasonal average optical field-of-view and local orientation estimates are obtained with uncertainties of 0.01 and 0.1°, respectively. Estimates of absolute sensitivity are repeatable to roughly 5 % from one month to the next, while the relative response between different wavelength channels is stable to better than 1 %. Astronomical field calibrations and darkroom calibration differences are on the order of 10 %. Atmospheric variability is the primary source of uncertainty; this may be reduced with complementary data from co-located instruments.

  10. Theoretical and experimental studies relevant to interpretation of auroral emissions

    NASA Technical Reports Server (NTRS)

    Keffer, Charles E.

    1992-01-01

    The results obtained in the second year of a three year collaborative effort with MSFC are summarized. A succession of experimental studies was completed to determine the effects of the natural and induced space vehicle environment on the measurement of auroral images from space-based platforms. In addition, a global model which incorporates both auroral and dayglow emission sources is being developed to allow interpretation of measured auroral emissions. A description of work completed on these two tasks is presented.

  11. Observations of Auroral Broadband Emissions by CLUSTER

    NASA Astrophysics Data System (ADS)

    Wahlund, J.-E.; et al.

    2003-04-01

    We present the results of a study based on several events of auroral broadband ULF/ELF emissions observed by the CLUSTER multi-spacecraft at distances around 4-5 RE. These emissions, observed below the ion plasma frequency, have similar dispersion characteristics as the broadband emissions observed at lower altitudes (800-4000 km) by e.g. rockets (e.g. AMICIST) and satellites (e.g. FREJA and FAST). As successive passages of the four CLUSTER satellites through nearly the same regions show, the intensity of the emissions depend on the thermal properties of the plasma and gradients thereof. The total Poynting flux is downward and is comparable to energy fluxes observed at lower altitudes. We therefore believe that the broadband emissions observed by CLUSTER in the auroral region are consistent with dispersed linear polarised Alfvén waves (DAW) transporting energy downward to the ionosphere guided by the magnetic field lines. These waves are therefore an important aspect for the energy transport for the auroral processes leading to particle acceleration when dissipating part or all their energy along the propagation path by wave-particle coupling, causing ion heating, suprathermal electron bursts and higher frequency ion-mode waves and possibly also electric potential structures. Intermittent auroral arc features have been observed embedded in a larger region of broadband emissions. The multi-spacecraft measurements by CLUSTER here show the temporal development of sharp density gradients and intensified broadband waves together with the formation of electric potential structures and particle acceleration within the larger scale density cavity.

  12. New imaging spectrometer for auroral research

    SciTech Connect

    Rairden, R.; Swenson, G.

    1994-12-31

    A Loral 1024 x 1024 CCD array with 15-micron pixels has been incorporated as the focal plane detector in a new imaging spectrometer for auroral research. The large format low-noise CCD provides excellent dynamic range and signal to noise characteristics with image integration times on the order of 60 seconds using f/1.4 camera optics. Further signal enhancement is achieved through on-CCD pixel binning. In the nominal binned mode the instrument wavelength resolution varies from 15 to 30 {angstrom} across the 5000 to 8600 {angstrom} spectral range. Images are acquired and stored digitally on a Macintosh computer. This instrument was operated at a field site in Godhavn, Greenland during the past two winters (1993, 1994) to measure the altitude distribution of the various spectral emissions within auroral arcs. The height resolution on an auroral feature 300 km distant is {approximately}1 km. Examples of these measurements are presented here in snapshot and summary image formats illustrating the wealth of quantitative information provided by this new imaging spectrometer.

  13. Altitude Dependent Auroral Ion Diffusion Coefficients

    NASA Astrophysics Data System (ADS)

    Ludlow, G. R.

    2011-12-01

    Simultaneous upgoing auroral H+ and O+ ion beams generate ion acoustic waves which have both parallel and oblique wave vectors with respect to the ambient magnetic field. A parallel mode is investigated with phase velocity UO + CO in the direction of beam propagation, where UO is the oxygen beam velocity and CO is the oxygen ion sound speed. Due to the mass difference, this mode preferentially resonates with the oxygen beam through the n = 1 cyclotron resonance, causing O+ ions to diffuse in a direction that is primarily perpendicular to the background magnetic field. The Landau resonance (n = 0) is very narrow in parallel velocity and does not interact with either ion beam. In one case study the parallel acoustic mode begins to resonate with O+ ions within the auroral acceleration region and this resonant region in velocity space sweeps through the entire O+ beam as it moves into weaker magnetic field regions. The O+ quasilinear diffusion coefficients are examined during this process. Perpendicular diffusion becomes significant when the parallel resonant velocity is close to the parallel group velocity of the waves. This selects regions of velocity space where perpendicular diffusion is maximum which occurs at the leading edge of the resonant region as it sweeps through the O+ beam. In k - space these resonant velocities correspond to the regions of peak growth rate. The relevance of this work to the selective energization of heavy auroral ion beams will be discussed.

  14. Investigation of electrical currents in the auroral ionosphere

    NASA Technical Reports Server (NTRS)

    Arnoldy, R. L.

    1978-01-01

    Two papers are presented on the investigation of electrical currents in the auroral ionosphere: (1) The Relationship Between Field-Aligned Current Carried by Suprathermal Electrons, and the Auroral Arc; and (2) Ionospheric Electrical Currents in the Late Evening Plasma Flow Reversal. In the first paper (1), data from four auroral sounding rockets, which directly measured field-aligned currents with partical detectors, are presented. In the second paper (2), data are presented for an instrumented sounding rocket that was launched from Andoya, Norway in January 1977, in the late evening auroral oval.

  15. Nightside auroral zone and polar cap ion outflow as a function of substorm size and phase

    NASA Astrophysics Data System (ADS)

    Wilson, G. R.; Ober, D. M.; Germany, G. A.; Lund, E. J.

    2004-02-01

    Because the high latitude ionosphere is an important source of plasma for the magnetosphere under active conditions, we have undertaken a study of the way ion outflow from the nightside auroral zone and polar cap respond to substorm activity. We have combined data from the Ultraviolet Imager (UVI) on Polar with ion upflow measurements from the TEAMS instrument on the FAST spacecraft to construct a picture of ion upflow from these regions as a function of substorm size and as a function of time relative to substorm onset. We use data taken during solar minimum in the northern hemisphere between December 1996 and February 1997. We find that the total nightside auroral zone ion outflow rate (averaged over substorm phase) depends on the size of the substorm, increasing by about a factor of 10 for both O+ and H+ from the smallest to the largest substorms in our study. The combined outflow rate from both the polar cap and the nightside auroral zone goes up by a factor of 7 for both ions for the same change in conditions. Regardless of storm size, the nightside auroral zone outflow rate increases by about a factor of 2 after onset, reaching its peak level after about 20 min. These results indicate that the change in the nightside auroral zone ion outflow rate that accompanies substorm onset is not as significant as the change from low to high magnetic activity. As a consequence, the prompt increase in the near earth plasma sheet energy density of O+ and H+ ions that accompanies onset [, 1996] is likely due to local energization of ions already present rather than to the sudden arrival and energization of fresh ionospheric plasma.

  16. Mathemagenic Activities Program: [Reports on Constructivism].

    ERIC Educational Resources Information Center

    Smock, Charles D., Ed.

    This set of five papers is related to the Mathemagenic Activities Program (MAP) for early childhood education of the University of Georgia's Follow Through Program. The MAP is based on Piagetian theory and provides sequentially structured sets of curriculum materials and processes that are designed to continually challenge children to learn about…

  17. Solar Array and Auroral Charging Studies of DMSP Spacecraft

    NASA Technical Reports Server (NTRS)

    Matias, Kelwin

    2013-01-01

    The SSJ electrostatic analyzers and the SSIES plasma instruments on the DMSP spacecraft in low Earth polar orbit can be used to conduct case studies of auroral and solar array charging. We will use a program written in the Interactive Data Language (IDL) to evaluate questionable charging events in the SSJ records by comparing charging signatures in SSJ and SSIES data. In addition, we will assemble a number of case studies of solar array charging showing the signatures from the SSJ data and compare them to the SSIES charging signatures. In addition, we will use Satellite Tool Kit (STK) to propagate orbits, obtain solar intensity, and use to verify onset of charging with sunrise.

  18. Spectral evidence for stirring scales and two-dimensional turbulence in the auroral ionosphere

    NASA Technical Reports Server (NTRS)

    Earle, G. D.; Kelley, M. C.

    1993-01-01

    Electric field power spectra from two auroral sounding rocket flights show evidence of a distinct scale size regime for injection of energy into the auroral oval. The signature of this process is a broad plateau in the spectrum, with power law dependences at both shorter and longer scale sizes. We argue that the spectral properties at high k are dominated by processes occurring near the edges of inverted-V electron precipitation regions (auroral arcs). We see no compelling reason to conclude that a linear local plasma instability is occurring but rather, that nonlinear mixing and forward cascade yield the observed velocity field. The spectra of simultaneously observed density irregularities are quite different from those of the electric field, implying that the plasma density does not behave as a passive scalar in the auroral zone during active conditions. At low-k values we show that the rocket spectra are consistent with the power spectra of magnetospheric electric fields measured by the DE, AE-C, and Hilat stallites.

  19. Evidence of auroral plasma cavities at Uranus and Neptune from radio burst observations

    NASA Technical Reports Server (NTRS)

    Farrell, W. M.; Desch, M. D.; Kaiser, M. L.; Calvert, W.

    1991-01-01

    Radio bursts originating from the stronger magnetic polar regions of both Uranus and Neptune were detected by the planetary radio astronomy experiment during the Voyager 2 encounters with the planets. It has previously been demonstrated that these bursts are beamed into a broad, hollow emission pattern from their auroral sources. It is now shown that the bursts at both planets also manifest similar detailed patterns, with the waves beamed into two separate and distinct radiation cones at intermediate wave frequencies. This double-cone emission pattern is predicted by relativistic cyclotron resonance theory, and application of this theory to the observed emission pattern yields the plasma density structure within the radio source region. Calculations indicate that at both Uranus and Neptune the plasma-to-cyclotron frequency ratio can drop well below 0.01 within the active region. Such low values indicate that the southern auroral zones at both planets contain an auroral plasma cavity that is similar to that found in earth's nightside auroral zone.

  20. Physical activity opportunities in afterschool programs

    PubMed Central

    Weaver, R. Glenn; Beets, Michael W.; Huberty, Jennifer; Freedman, Darcy; Turner-Mcgrievy, Gabrielle; Ward, Diane

    2015-01-01

    Afterschool programs (ASPs) have potential to provide children moderate-to-vigorous physical activity (MVPA). The availability and types (e.g., free play or organized activities) of physical activity opportunities, their structure (e.g., presence of lines, elimination games), and staff behaviors (e.g., encouragement, engaged) can influence children’s MVPA. This study explored these factors in 20 ASPs serving over 1,700 elementary-age children. The occurrence, types and structure of physical activity opportunities, and staff behaviors were collected via the System for Observing Staff Promotion of Physical Activity and Nutrition (SOSPAN). A total of 4,660 SOSPAN scans were completed across 63 complete program days (1733 during physical activity opportunities). Physical activity opportunities were observed on 60 program days across all 20 sites, with 73% of those opportunities classified as free play. ASPs scheduled an average of 66.3 minutes (range 15-150min) of physical activity opportunities daily. Games played included basketball, tag, soccer and football. Staff rarely engaged in physical activity promotion behaviors, and the structure of organized games discouraged MVPA. For example, staff verbally promoted physical activity in just 6.1% of scans, while organized games were more likely to involve lines and elimination. Professional development training may enhance staffs’ physical activity promotion and the structure of activity opportunities. PMID:25586132

  1. Physical activity opportunities in afterschool programs.

    PubMed

    Weaver, R Glenn; Beets, Michael W; Huberty, Jennifer; Freedman, Darcy; Turner-Mcgrievy, Gabrielle; Ward, Diane

    2015-05-01

    Afterschool programs (ASPs) have potential to provide children moderate to vigorous physical activity (MVPA). The availability and types (e.g., free play or organized activities) of physical activity opportunities, their structure (e.g., presence of lines, elimination games), and staff behaviors (e.g., encouragement, engaged) can influence children's MVPA. This study explored these factors in 20 ASPs serving over 1,700 elementary-age children. The occurrence, types, and structure of physical activity opportunities, and staff behaviors were collected via the SOSPAN (System for Observing Staff Promotion of Physical Activity and Nutrition). A total of 4,660 SOSPAN scans were completed across 63 complete program days (1,733 during physical activity opportunities). Physical activity opportunities were observed on 60 program days across all 20 sites, with 73% of those opportunities classified as free play. ASPs scheduled an average of 66.3 minutes (range 15-150 minutes) of physical activity opportunities daily. Games played included basketball, tag, soccer, and football. Staff rarely engaged in physical activity promotion behaviors, and the structure of organized games discouraged MVPA. For example, staff verbally promoted physical activity in just 6.1% of scans, while organized games were more likely to involve lines and elimination. Professional development training may enhance staffs' physical activity promotion and the structure of activity opportunities. PMID:25586132

  2. Physical activity opportunities in afterschool programs.

    PubMed

    Weaver, R Glenn; Beets, Michael W; Huberty, Jennifer; Freedman, Darcy; Turner-Mcgrievy, Gabrielle; Ward, Diane

    2015-05-01

    Afterschool programs (ASPs) have potential to provide children moderate to vigorous physical activity (MVPA). The availability and types (e.g., free play or organized activities) of physical activity opportunities, their structure (e.g., presence of lines, elimination games), and staff behaviors (e.g., encouragement, engaged) can influence children's MVPA. This study explored these factors in 20 ASPs serving over 1,700 elementary-age children. The occurrence, types, and structure of physical activity opportunities, and staff behaviors were collected via the SOSPAN (System for Observing Staff Promotion of Physical Activity and Nutrition). A total of 4,660 SOSPAN scans were completed across 63 complete program days (1,733 during physical activity opportunities). Physical activity opportunities were observed on 60 program days across all 20 sites, with 73% of those opportunities classified as free play. ASPs scheduled an average of 66.3 minutes (range 15-150 minutes) of physical activity opportunities daily. Games played included basketball, tag, soccer, and football. Staff rarely engaged in physical activity promotion behaviors, and the structure of organized games discouraged MVPA. For example, staff verbally promoted physical activity in just 6.1% of scans, while organized games were more likely to involve lines and elimination. Professional development training may enhance staffs' physical activity promotion and the structure of activity opportunities.

  3. Activity-Centric Approach to Distributed Programming

    NASA Technical Reports Server (NTRS)

    Levy, Renato; Satapathy, Goutam; Lang, Jun

    2004-01-01

    The first phase of an effort to develop a NASA version of the Cybele software system has been completed. To give meaning to even a highly abbreviated summary of the modifications to be embodied in the NASA version, it is necessary to present the following background information on Cybele: Cybele is a proprietary software infrastructure for use by programmers in developing agent-based application programs [complex application programs that contain autonomous, interacting components (agents)]. Cybele provides support for event handling from multiple sources, multithreading, concurrency control, migration, and load balancing. A Cybele agent follows a programming paradigm, called activity-centric programming, that enables an abstraction over system-level thread mechanisms. Activity centric programming relieves application programmers of the complex tasks of thread management, concurrency control, and event management. In order to provide such functionality, activity-centric programming demands support of other layers of software. This concludes the background information. In the first phase of the present development, a new architecture for Cybele was defined. In this architecture, Cybele follows a modular service-based approach to coupling of the programming and service layers of software architecture. In a service-based approach, the functionalities supported by activity-centric programming are apportioned, according to their characteristics, among several groups called services. A well-defined interface among all such services serves as a path that facilitates the maintenance and enhancement of such services without adverse effect on the whole software framework. The activity-centric application-program interface (API) is part of a kernel. The kernel API calls the services by use of their published interface. This approach makes it possible for any application code written exclusively under the API to be portable for any configuration of Cybele.

  4. Comprehensive School Physical Activity Programs. Position Statement

    ERIC Educational Resources Information Center

    National Association for Sport and Physical Education, 2008

    2008-01-01

    The National Association for Sport and Physical Education (NASPE) recommends that all PK-12 schools implement a Comprehensive School Physical Activity Program. Schools play an important role in public health, and the physical, mental, and social benefits of regular physical activity for youth are well documented. Leading public health, medical,…

  5. A case-study of the evolution of polar-cap currents and auroral electrojets during polar geomagnetic disturbances with IMS magnetometer data

    NASA Technical Reports Server (NTRS)

    Iijima, T.; Kim, J. S.; Sugiura, M.

    1984-01-01

    The development of the polar cap current and the relationship of that development to the evolution of auroral electrojets during individual polar geomagnetic disturbances is studied using 1 min average data from US-Canada IMS network stations and standard magnetograms from sites on the polar cap and in the auroral zone. It is found that even when the auroral electrojet activity is weak, polar cap currents producing fields of magnitude approximately 100-200 nT almost always exist. A normal convection current system exists quasi-persistently in the polar cap during extended quiet or weakly disturbed periods of auroral electrojet activity. After one such period, some drastic changes occur in the polar cap currents, which are followed by phases of growth, expansion, and recovery. Polar cap currents cannot all be completely ascribed to a single source mechanism.

  6. Field Operations Program Activities Status Report

    SciTech Connect

    J. E. Francfort; D. V. O'Hara; L. A. Slezak

    1999-05-01

    The Field Operations Program is an electric vehicle testing and evaluation program sponsored by US Department of Energy and managed by the Idaho National Engineering and Environmental Laboratory. The Program's goals are to evaluate electric vehicles in real-world applications and environments, support electric vehicle technology advancement, develop infrastructure elements necessary to support significant electric vehicle use, support increased use of electric vehicles in federal fleets, and increase overall awareness and acceptance of electric vehicles. This report covers Program activities from fiscal year 1997 through mid-fiscal year 1999. The Field Operations Program succeeded the Site Operator Program, which ended in September 1996. Electric vehicle testing conducted by the Program includes baseline performance testing (EV America testing), accelerated reliability (life-cycle) testing, and fleet testing. The baseline performance parameters include accelerations, braking, range, energy efficiency, and charging time. The Program collects accelerated reliability and fleet operations data on electric vehicles operated by the Program's Qualified Vehicle Testing (QVT) partners. The Program's QVT partners have over 3 million miles of electric vehicle operating experience.

  7. Temporal Development of Auroral Acceleration Potentials: High-Altitude Evolutionary Sequences, Drivers and Consequences

    NASA Astrophysics Data System (ADS)

    Hull, A. J.; Wilber, M.; Chaston, C.; Bonnell, J.; Mozer, F.; McFadden, J.; Goldstein, M.; Fillingim, M.

    2007-12-01

    The region above the auroral acceleration region is an integral part of the auroral zone electrodynamic system. At these altitudes (≥ 3 Re) we find the source plasma and fields that determine acceleration processes occurring at lower altitudes, which play a key role in the transport of mass and energy into the ionosphere. Dynamic changes in these high-altitude regions can affect and/or control lower-altitude acceleration processes according to how field-aligned currents and specific plasma sources form and decay and how they are spatially distributed, and through magnetic configuration changes deeper in the magnetotail. Though much progress has been made, the time development and consequential effects of the high-altitude plasma and fields are still not fully understood. We present Cluster multi-point observations at key instances within and above the acceleration region (> 3 RE) of evolving auroral arc current systems. Results are presented from events occurring under different conditions, such as magnetospheric activity, associations with density depletions or gradients, and Alfvenic turbulence. A preliminary survey, primarily at or near the plasma sheet boundary, indicates quasi- static up-down current pair systems are at times associated with density depletions and other instances occur in association with density gradients. The data suggest that such quasi-static current systems may be evolving from structured Alfvenic current systems. We will discuss the temporal development of auroral acceleration potentials, plasma and currents, including quasi-static system formation from turbulent systems of structured Alfvenic field-aligned currents, density depletion and constituent reorganization of the source and ionospheric plasma that transpire in such systems. Of particular emphasis is how temporal changes in magnetospheric source plasma and fields affect the development of auroral acceleration potentials at lower altitudes.

  8. Production of nitrous oxide in the auroral D and E regions

    NASA Technical Reports Server (NTRS)

    Zipf, E. C.; Prasad, S. S.

    1980-01-01

    A study of nitrous oxide formation mechanisms indicates that N2O concentrations greater than 10 to the 9th per cu cm could be produced in IBC III aurora or by lower-level activity lasting for many hours, and, in favorable conditions, the N2O concentration could exceed the local nitric oxide density. An upper limit on the globally averaged N2O production rate from auroral activity is estimated at 2 x 10 to the 27th per second.

  9. Midnight Sector Observations of Auroral Omega Bands

    NASA Astrophysics Data System (ADS)

    Wild, J. A.; Woodfield, E. E.; Donovan, E. F.; Fear, R. C.; Grocott, A.; Lester, M.; Fazakerley, A. N.; Lucek, E. A.; Kadokura, A.; Hosokawa, K.; Carlson, C. W.; McFadden, J. P.; Glassmeier, K.; Angelopoulos, V.; Björnsson, G.

    2010-12-01

    We present observations of auroral omega bands on 28 September 2009. Although generally associated with the substorm recovery phase and typically observed in the morning sector, the omega bands presented here occurred just after expansion phase onset and were observed in the midnight sector, immediately dawnward of the onset region. The Tjörnes “Rainbow” all-sky imager, located in north-eastern Iceland, revealed that the omega bands were ˜200 km in scale and propagated eastward from the onset region at ˜0.4 km/s while a co-located ground magnetometer recorded the simultaneous passage of Ps 6 pulsations. Although somewhat smaller and slower-moving than the majority of previously reported omega bands, the observed structures were clear examples of this phenomenon, albeit in an atypical location and much earlier in the substorm cycle than is usual. During the study interval the THEMIS A and C probes provided detailed measurements of the upstream interplanetary environment while the Cluster spacecraft were located in the tail plasma sheet conjugate to the ground-based all-sky imager. Cluster observed pulsed fluxes of electrons moving parallel to the magnetic field towards the northern hemisphere auroral ionosphere. Despite mapping uncertainties, there is some suggestion that keV electron fluxes in the tail were related to the auroral emissions in the omega bands. We suggest that omega band formation may be linked to expansion phase onset in the midnight sector and that the finite propagation speed through post-midnight and early morning local times may account for the interpretation of omega bands as a morning sector recovery phase phenomenon.

  10. Effect of Energetic Electrons on Quiet Auroral Arc Formation

    NASA Astrophysics Data System (ADS)

    Hasegawa, Hiroki; Ohno, Nobuaki; Sato, Tetsuya

    2010-11-01

    The theory of feedback instability between the magnetosphere and ionosphere is believed as one of the candidate to explain the formation of quiet auroral arc. Then, some magneto-hydro- dynamics simulations showed the arc formation by this macroscopic instability, while the effect of auroral energetic electrons on the arc formation was neglected or given as a macroscopic parameter in these simulations. On the other hand, because of the recent development of particle simulations, auroral energetic electrons are thought to be produced by the super ion-acoustic double layer that should be created by microscopic instability. To make close investigation of auroral arc formation, it is necessary to consider the interaction with microscopic instability. In this paper, we numerically study the effect of energetic electrons on quiet auroral arc formation by means of the Macro-Micro Interlocked simulation.

  11. Electron Precipitation Associated with Small-Scale Auroral Structures

    NASA Astrophysics Data System (ADS)

    Michell, R.; Samara, M.; Grubbs, G. A., II; Hampton, D. L.; Bonnell, J. W.; Ogasawara, K.

    2014-12-01

    We present results from the Ground-to-Rocket Electrons Electrodynamics Correlative Experiment (GREECE) sounding rocket mission, where we combined high-resolution ground-based auroral imaging with high time-resolution precipitating electron measurements. The GREECE payload successfully launched from Poker Flat, Alaska on 03 March 2014 and reached an apogee of approximately 335 km. The narrow field-of-view auroral imaging was taken from Venetie, AK, which is directly under apogee. This enabled the small-scale auroral features at the magnetic footpoint of the rocket payload to be imaged in detail. The electron precipitation was measured with the Acute Precipitating Electron Spectrometer (APES) onboard the payload. Features in the electron data are matched up with their corresponding auroral structures and boundaries, enabling measurement of the exact electron distributions responsible for the specific small-scale auroral features. These electron distributions will then be used to infer what the potential electron acceleration processes were.

  12. The magnetoionic modes and propagation properties of auroral radio emissions

    NASA Technical Reports Server (NTRS)

    Calvert, Wynne; Hashimoto, Kozo

    1990-01-01

    The nature of the magnetoionic wave modes which accompany the aurora is clarified here by a detailed analysis, using multiple techniques, of DE 1 auroral radio observations. All four of the possible magnetoionic wave modes are found to occur, apparently emitted from two different source regions on the same auroral field line. AKR originates primarily in the X mode near the electron cyclotron frequency, and is frequently also accompanied by a weaker O-mode component from the same location. The next most prominent auroral emission is the W-mode auroral hiss originating from altitudes always well below the DE 1 satellite at frequencies below the local cyclotron frequency. The previously reported Z-mode auroral radiation was also detected, but from sources also below the satellite at the poleward edge of the cavity, and not from the expected AKR source at the cyclotron frequency.

  13. Double layers on auroral field lines

    NASA Technical Reports Server (NTRS)

    Hudson, M. K.; Lotko, W.; Witt, E.

    1982-01-01

    Time-stationary solutions to the Vlasov-Poisson equation for ion holes and double layers were examined along with particle simulations which pertain to recent observations of small amplitude (e phi)/t sub e approx. 1 electric field structures on auroral field lines. Both the time-stationary analysis and the simulations suggest that double layers evolve from holes in ion phase space when their amplitude reaches (e phi)/t sub e approx. 1. Multiple small amplitude double layers which are seen in long simulation systems and are seen to propagate past spacecraft may account for the acceleration of plasma sheet electrons to produce the discrete aurora.

  14. Atmospheric spreading of protons in auroral arcs

    NASA Technical Reports Server (NTRS)

    Iglesias, G. E.; Vondrak, R. R.

    1974-01-01

    A model is developed to calculate the effect of atmospheric spreading on the flux and angular distribution of protons in homogeneous auroral arcs. An expression is derived that indicates the angular distribution in the atmosphere as a function of distance from arc center, neutral scale height, arc width, and initial angular distribution. The results of the model agree favorably with those based on Monte-Carlo calculations. From these results the enhancement factors needed to compute the original proton current above the atmosphere are obtained. A technique is indicated for determining the incident angular distribution from rocket-based measurements of the arc width and angular distribution.

  15. Automatic georeferencing of astronaut auroral photography

    NASA Astrophysics Data System (ADS)

    Riechert, Maik; Walsh, Andrew P.; Gerst, Alexander; Taylor, Matthew G. G. T.

    2016-07-01

    Astronauts on board the International Space Station (ISS) have taken thousands of high-resolution colour photographs of the aurora, which could be made useful for research if their pointing information could be reconstructed. We describe a method to do this using the star field in the images, and how the reconstructed pointing can then be used to georeference the images to a similar level of accuracy in existing all-sky camera images. We have used this method to make georeferenced auroral images taken from the ISS available and here describe the resulting data set, processing software, and how to access them.

  16. Local Geomagnetic Indices and the Prediction of Auroral Power

    NASA Astrophysics Data System (ADS)

    Newell, P. T.; Gjerloev, J. W.

    2014-12-01

    As the number of magnetometer stations and data processing power increases, just how auroral power relates to geomagnetic observations becomes a quantitatively more tractable question. This paper compares Polar UVI auroral power observations during 1997 with a variety of geomagnetic indices. Local time (LT) versions of the SuperMAG auroral electojet (SME) are introduced and examined, along with the corresponding upper and lower envelopes (SMU and SML). Also, the East-West component, BE, is investigated. We also consider whether using any of the local indices is actually better at predicting local auroral power than a single global index. Each index is separated into 24 LT indices based on a sliding 3-h MLT window. The ability to predict - or better reconstruct - auroral power varies greatly with LT, peaking at 1900 MLT, where about 75% of the variance (r2) can be predicted at 1-min cadence. The aurora is fairly predictable from 1700 MLT - 0400 MLT, roughly the region in which substorms occur. Auroral power is poorly predicted from auroral electrojet indices from 0500 MLT - 1500 MLT, with the minima at 1000-1300 MLT. In the region of high predictability, the local variable which works best is BE, in contrast to long-standing expectations. However using global SME is better than any local variable. Auroral power is best predicted by combining global SME with a local index: BE from 1500-0200 MLT, and either SMU or SML from 0300-1400 MLT. In the region of the diffuse aurora, it is better to use a 30 min average than the cotemporaneous 1-min SME value, while from 1500-0200 MLT the cotemporaneous 1-min SME works best, suggesting a more direct physical relationship with the auroral circuit. These results suggest a significant role for discrete auroral currents closing locally with Pedersen currents.

  17. Geotail Measurements Compared with the Motions of High-Latitude Auroral Boundaries during Two Substorms

    NASA Technical Reports Server (NTRS)

    Maynard, N. C.; Burke, W. J.; Erickson, G. M.; Nakamura, M.; Mukai, T.; Kokubun, S.; Yamamoto, T.; Jacobsen, B.; Egeland, A.; Samson, J. C.; Weimer, D. R.; Reeves, G. D.; Luhr, H.

    1997-01-01

    Geotail plasma and field measurements at -95 R(sub E) are compared with extensive ground-based, near-Earth, and geosynchronous measurements to study relationships between auroral activity and magnetotail dynamics during the expansion phases of two substorms. The studied intervals are representative of intermittent, moderate activity. The behavior of the aurora and the observed effects at Geotail for both events are harmonized by the concept of the activation of near-Earth X lines (NEXL) after substorm onsets, with subsequent discharges of one or more plasmoids down the magnetotail. The plasmoids must be viewed as three-dimensional structures which are spatially limited in the dawn-dusk direction. Also, reconnection at the NEXL must proceed at variable rates on closed magnetic field lines for significant times before beginning to reconnect lobe flux. This implies that the plasma sheet in the near-Earth magnetotail is relatively thick in comparison with an embedded current sheet and that both the NEXL and distant X line can be active simultaneously. Until reconnection at the NEXL engages lobe flux, the distant X line maintains control of the poleward auroral boundary. If the NEXL remains active after reaching the lobe, the auroral boundary can move poleward explosively. The dynamics of high-latitude aurora in the midnight region thus provides a means for monitoring these processes and indicating when significant lobe flux reconnects at the NEXL.

  18. Determining the source region of auroral emissions in the prenoon oval using coordinated Polar BEAR UV-imaging and DMSP particle measurements

    SciTech Connect

    Newell, P.T.; Meng, C.I. ); Huffman, R.E. )

    1992-08-01

    The Polar Beacon Experiment and Auroral Research (Polar BEAR) satellite included the capability for imaging the dayside auroral oval in full sunlight at several wavelengths. The authors compare particle observations from the DMSP F7 satellite during dayside auroral oval crossings with approximately simultaneous Polar BEAR 1,356-{angstrom} images to determine the magnetospheric source region of the dayside auroral oval. The source region is determined from the Defense Meteorological Satellite Program (DMSP) particle data, according to recent work concerning the classification and identification of precipitation source regions. The close DMSP/Polar BEAR coincidences all occur when the former satellite is located between 0945 and 1,000 MLT. The authors found instances of auroral arcs mapping to each of several different regions, including the boundary plasma sheet, the low-latitude boundary layer, and the plasma mantle. However, the results indicate that about half the time the most prominent auroral arcs are located at the interfaces between distinct plasma regions, at least at the local time studied here.

  19. E and F region study of the evening sector auroral oval - A Chatanika/Dynamics Explorer 2/NOAA 6 comparison

    NASA Technical Reports Server (NTRS)

    Senior, C.; Sharber, J. R.; Winningham, J. D.; De La Beaujardiere, O.; Heelis, R. A.; Evans, D. S.; Sugiura, M.; Hoegy, W. R.

    1987-01-01

    Simultaneous data from the Chatanika radar and the DE 2 and NOAA 6 satellites are used to study the typical behavior of the winter evening-sector auroral plasma during moderate and steady magnetic activity. The equatorward edge of the auroral E layer, of the region 2 field-aligned currents, and of the region of intense convection are colocated. The auroral E layer extends several degrees south of the equatorward edge of the keV electron precipitation from the CPS. Although the main trough and ionization channel are embedded in a region of intense electric field where the plasma flows sunward at high speed, the flux tubes associated with these two features have different time histories. The midlatitude trough is located south of the region of electron precipitation, above a proton aurora. The ionization channel marks the poleward edge of the main trough and is colocated with the equatorward boundary of the electron precipitation from the central plasma sheet.

  20. Auroral weak double layers: A critical assessment

    NASA Astrophysics Data System (ADS)

    Koskinen, Hannu E. J.; Mälkki, Anssi M.

    Weak double layers (WDLs) were first observed in the mid-altitude auroral magnetosphere in 1976 by the S3-3 satellite. The observations were confirmed by Viking in 1986, when more detailed information of these small-scale plasma structures became available. WDLs are upward moving rarefactive solitary structures with negative electric potential. The potential drop over a WDL is typically 0-1 V with electric field pointing predominantly upward. The structures are usually found in relatively weak (≤2 kV) auroral acceleration regions where the field-aligned current is upward, but sometimes very small. The observations suggest that WDLs exist in regions of cool electron and ion background. Most likely the potential structures are embedded in the background ion population that may drift slowly upward. There have been several attempts for plasma physical explanation of WDLs but so far the success has not been very good. Computer simulations have been able to produce similar structures, but usually for somewhat unrealistic plasma parameters. A satisfactory understanding of the phenomenon requires consideration of the role of WDLs in the magnetosphere-ionosphere (MI) coupling, including the large-scale electric fields, both parallel and perpendicular to the magnetic field, and the Alfvén waves mediating the coupling. In this report we give a critical review of our present understanding of WDLs. We try to find out what can be safely deduced from the observations, what are just educated guesses, and where we may go wrong.

  1. Numerical investigation of auroral cyclotron maser processes

    SciTech Connect

    Speirs, D. C.; Ronald, K.; McConville, S. L.; Gillespie, K. M.; Phelps, A. D. R.; Cross, A. W.; Robertson, C. W.; Whyte, C. G.; He, W.; Bingham, R.; Vorgul, I.; Cairns, R. A.; Kellett, B. J.

    2010-05-15

    When a mainly rectilinear electron beam is subject to significant magnetic compression, conservation of magnetic moment results in the formation of a horseshoe shaped velocity distribution. It has been shown that such a distribution is unstable to cyclotron emission and may be responsible for the generation of auroral kilometric radiation--an intense rf emission sourced at high altitudes in the terrestrial auroral magnetosphere. Particle-in-cell code simulations have been undertaken to investigate the dynamics of the cyclotron emission process in the absence of cavity boundaries with particular consideration of the spatial growth rate, spectral output and rf conversion efficiency. Computations reveal that a well-defined cyclotron emission process occurs albeit with a low spatial growth rate compared with waveguide bounded simulations. The rf output is near perpendicular to the electron beam with a slight backward-wave character reflected in the spectral output with a well defined peak at 2.68 GHz, just below the relativistic electron cyclotron frequency. The corresponding rf conversion efficiency of 1.1% is comparable to waveguide bounded simulations and consistent with the predictions of kinetic theory that suggest efficient, spectrally well defined emission can be obtained from an electron horseshoe distribution in the absence of radiation boundaries.

  2. ISIS-II Scanning Auroral Photometer.

    PubMed

    Anger, C D; Fancott, T; McNally, J; Kerr, H S

    1973-08-01

    The ISIS-II dual wavelength scanning auroral photometer is designed to map the distribution of auroral emissions at 5577 A and 3914 A over the portion of the dark earth visible to the spacecraft. A combination of internal electronic scanning and the natural orbital and rotational motions of the spacecraft causes a dual wavelength photometer to be scanned systematically across the earth. The data will be reproduced directly in the form of separate pictures representing emissions at each wavelength, which will be used to study the large-scale distribution and morphology of auroras, to study the ratio of 3914-A and 5577-A emissions thought to depend upon the energies of exciting particles), and to compare with results from other instruments on board the spacecraft and on the ground. The Red Line Photometer experiment on the same spacecraft is described in an accompanying paper by Shepherd et al. [Appl. Opt. 12, 1767 (1973)]. The instrument can be thought of as the photometric equivalent of an all-sky color camera which will view the aurora from above instead of below and with a much wider vantage point unobstructed by cloud and haze. In one satellite pass, the instrument will be capable of surveying (in one hemisphere) the entire polar region in which auroras normally occur. PMID:20125605

  3. Cluster in the Auroral Acceleration Region

    NASA Technical Reports Server (NTRS)

    Pickett, Jolene S.; Fazakerley, Andrew N.; Marklund, Gorun; Dandouras, Iannis; Christopher, Ivar W.; Kistler, Lynn; Lucek, Elizabeth; Masson, Arnaud; Taylor, Matthew G.; Mutel, Robert L.; Santolik, Ondrej; Bell, Timothy F.; Fung, Shing; Pottelette, Raymond; Hanasz, Jan; Schreiber, Roman; Hull, Arthur J.

    2010-01-01

    Due to a fortuitous evolution of the Cluster orbit, the Cluster spacecraft penetrated for the first time in its mission the heart of Earth's auroral acceleration region (AAR) in December 2009 and January 2010. During this time a special AAR campaign was carried out by the various Cluster instrument teams with special support from ESA and NASA facilities. We present some of the first multi-spacecraft observations of the waves, particles and fields made during that campaign. The Cluster spacecraft configuration during these AAR passages was such that it allowed us to explore the differences in the signatures of waves, particles, and fields on the various spacecraft in ways not possible with single spacecraft. For example, one spacecraft was more poleward than the other three (C2), one was at higher altitude (C1), and one of them (0) followed another (C4) through the AAR on approximately the same track but delayed by three minutes. Their separations were generally on the order of a few thousand km or less and occasionally two of them were lying along the same magnetic field line. We will show some of the first analyses of the data obtained during the AAR campaign, where upward and downward current regions, and the waves specifically associated with those regions, as well as the auroral cavities, were observed similarly and differently on the various spacecraft, helping us to explore the spatial, as well as the temporal, aspects of processes occurring in the AAR.

  4. Mapping thermospheric winds in the auroral zone

    NASA Astrophysics Data System (ADS)

    Conde, M.; Smith, R. W.

    A new all-sky imaging Fabry-Perot (ASIFP) spectrometer has been developed for ground-based mapping of upper atmospheric wind and temperature fields in the auroral zone. Although several other ASIFP spectrometers exist for atmospheric studies [Rees et al., 1984; Sekar et al., 1993; Biondi et al., 1995] these instruments have all operated with etalons of fixed optical gap, a method potentially subject to errors in the presence of auroral intensity gradients. In this instrument the etalon plate spacing is scanned periodically over one order of interference and each photon detected is assigned to a wavelength interval which is determined from both its arrival location on the detector and the etalon plate spacing prevailing at the detection time. Spectra accumulated this way are not distorted by spatial intensity gradients. Preliminary λ630 nm observations were made during the winter of 1994/95 from Poker Flat Research Range, Alaska. To illustrate some of the features we have observed in this study we present line-of-sight wind estimates derived for the night of December 7, 1994. The background wind matches averages presented previously by Sica et al. [1986] and is consistent with winds driven principally by momentum deposition from ionospheric plasma convection through ion-drag. Smaller scale curvature and divergence features are also discernable and are discussed.

  5. Auroral precipitation and descent of thermospheric NO

    NASA Astrophysics Data System (ADS)

    Kühl, Sven; Espy, Patrick; Hibbins, Robert; Paxton, Larry; Funke, Bernd

    2016-07-01

    Energetic particle precipitation in Auroras (E <20 keV) produces nitric oxide (NO) in the upper meso- and lower thermosphere region (UMLT). The subsequent descent of the NO produced in the UMLT to the lower meso- and upper stratosphere is referred to as the energetic particle precipitation indirect effect (EPP IE). The downwelling of NO produced in Auroras alters the chemistry of the mesosphere and upper stratosphere (e.g. by the NOx cycle) and possibly has important effects also on its dynamics. By observations of auroral precipitation from SSUSI(DMSP) and measurements of NO from MIPAS(ENVISAT) and SMR(ODIN) we investigate the quantitative relation of the electron fluxes and characteristic energies of auroral precipitation to the NO produced in the lower thermosphere and the subsequent downwelling of NO. Using additional ground-based (e.g. Meteor Radar, Microwave Radiometer) and satellite observations (SOFIE) we attempt to quantify the EPP IE and its impact on atmospheric chemistry and dynamics.

  6. ISIS-II Scanning Auroral Photometer.

    PubMed

    Anger, C D; Fancott, T; McNally, J; Kerr, H S

    1973-08-01

    The ISIS-II dual wavelength scanning auroral photometer is designed to map the distribution of auroral emissions at 5577 A and 3914 A over the portion of the dark earth visible to the spacecraft. A combination of internal electronic scanning and the natural orbital and rotational motions of the spacecraft causes a dual wavelength photometer to be scanned systematically across the earth. The data will be reproduced directly in the form of separate pictures representing emissions at each wavelength, which will be used to study the large-scale distribution and morphology of auroras, to study the ratio of 3914-A and 5577-A emissions thought to depend upon the energies of exciting particles), and to compare with results from other instruments on board the spacecraft and on the ground. The Red Line Photometer experiment on the same spacecraft is described in an accompanying paper by Shepherd et al. [Appl. Opt. 12, 1767 (1973)]. The instrument can be thought of as the photometric equivalent of an all-sky color camera which will view the aurora from above instead of below and with a much wider vantage point unobstructed by cloud and haze. In one satellite pass, the instrument will be capable of surveying (in one hemisphere) the entire polar region in which auroras normally occur.

  7. Unusual rainbow and white rainbow: A new auroral candidate in oriental historical sources

    NASA Astrophysics Data System (ADS)

    Hayakawa, Hisashi; Isobe, Hiroaki; Davis Kawamura, Akito; Tamazawa, Harufumi; Miyahara, Hiroko; Kataoka, Ryuho

    2016-06-01

    Solar activity has been recorded as auroras or sunspots in various historical sources. These records are of great importance for investigating both long-term solar activities and extremely intense solar flares. According to previous studies, they were recorded as "vapor," "cloud," or "light," especially in oriental historical sources; however, this terminology has not been discussed adequately, and remains still quite vague. In this paper, we suggest the possibility of using "unusual rainbow" and "white rainbow" as candidates of historical auroras in oriental historical sources, and examine if this is probable. This discovery will help us to make more comprehensive historical auroral catalogues, and require us to add these terms to auroral candidates in oriental historical sources.

  8. Separation of spatial and temporal structure of auroral particle precipitation (Invited)

    NASA Astrophysics Data System (ADS)

    Boudouridis, A.; Spence, H.

    2013-12-01

    Knowledge of the dominant temporal and spatial scales of auroral features is instrumental in understanding the various mechanisms responsible for auroral particle precipitation. Single spacecraft data suffer from temporal/spatial ambiguity. In an effort to separate the temporal and spatial variations of the aurora, we use electron and ion precipitation data from two co-orbiting satellites, F6 and F8 of the Defense Meteorological Satellite Program (DMSP). The two spacecraft have almost identical polar orbits with a small difference in period. As a result the time difference between the two measurements varies with time. We use two statistical tools in order to determine the most probable lifetimes and spatial dimensions of the prevalent auroral features, Cross Correlation Analysis (CCA) and Cross Spectral Analysis (CSA). The CCA is applied to the magnetic latitude series of electron and ion, integral number and energy fluxes measured by the two DMSP spacecraft. As one spacecraft overtakes the other, the variable time lag between the two measurements results in different cross correlation of the two series. We explore the dependence of this variation on the time lag between the satellites. We find that the electron precipitation exhibits a decreasing correlation between the two spacecraft with increasing time lag, whereas there is only a small similar effect for the ion precipitation data. For the CSA we compute the so-called coherence function as a function of frequency (or inverse wavelength), and hence size of the auroral features. The coherence function is a measure of the stability of auroral features of different sizes. We investigate its variation as a function of the time separation between the two DMSP spacecraft measurements. We show that the coherence function of both electrons and ions remains high for up to 1.5 min spacecraft separations for all features larger than about 100 km in width. For smaller features the coherence is lower even for time lags of

  9. Discovering Community: Activities for Afterschool Programs

    ERIC Educational Resources Information Center

    National Institute on Out-of-School Time, Wellesley College, 2006

    2006-01-01

    The project activities highlighted in this publication were conducted within the framework of school-based afterschool programs operated by community-based organizations. The intention of the Discovering Community initiative, created by The After-School Corporation and MetLife Foundation, is to foster greater collaborations and mutual respect…

  10. On a possible connection between the longitudinally propagating near-Earth plasma sheet and auroral arc waves: A reexamination

    NASA Astrophysics Data System (ADS)

    Motoba, T.; Ohtani, S.; Donovan, E. F.; Angelopoulos, V.

    2015-01-01

    propagating low-frequency waves (or wavy structures) often occur in a localized region of the near-Earth plasma sheet and auroral arc immediately prior to auroral breakup. Although both are believed to be magnetospheric and ionospheric manifestations of a plasma sheet instability that may lead to substorm onset, the fundamental coupling processes behind their relationship are not yet understood. To address this question, we reexamined in detail a fortuitous conjunction event of prebreakup near-Earth plasma sheet and auroral arc waves, initially reported by Uritsky et al. (2009) using the Time History of Events and Macroscale Interactions during Substorms space-ground observations. The event exhibited a morphological one-to-one association between longitudinally propagating arc wave (LPAW) in the ionosphere and Pi2/Pc4 range wave activity in the plasma sheet. Our analysis revealed that (1) the LPAW was the periodic luminosity modulation of the growth phase arc by faint, diffuse, green line-dominated auroral patches propagating westward along/near the arc, rather than some type of small-scale arc structuring, such as auroral beads/rays/undulations; and (2) the plasma sheet wave, which had a diamagnetic nature, propagated duskward with accompanying coincident modulation of field-aligned fluxes of 0.1-30 keV electrons. These findings suggest that the LPAW was likely connected to the plasma sheet wave via modulated diffuse precipitation of hard plasma sheet electrons (> ~1 keV), not via filamentary field-aligned currents, as expected from the ballooning instability regime. Another potential implication is that such prebreakup low-frequency wave activity in the near-Earth plasma sheet is not necessarily guaranteed to initiate prebreakup auroral arc structuring.

  11. A Survey of Electron Beams Associated With Saturnian Auroral Hiss

    NASA Astrophysics Data System (ADS)

    Kopf, A.; Gurnett, D. A.; Hospodarsky, G. B.; Kurth, W. S.; Menietti, J. D.; Dougherty, M.; Mitchell, D. G.; Leisner, J. S.; Khurana, K. K.; Grimald, S.; Arridge, C. S.; Schippers, P.; Andre, N.; Coates, A. J.; Santolik, O.

    2009-12-01

    Over the last three years, the Cassini spacecraft underwent a series of high inclination orbits, allowing investigation and measurements of the Saturnian auroral zone. The Radio and Plasma Wave Science (RPWS) Investigation has detected low frequency funnel-shaped whistler mode emissions along the auroral field lines, much like the auroral hiss observed at Earth. The poleward and equatorward flaring of the auroral hiss funnel on the frequency-time spectrogram is the result of whistler mode waves propagating upward into a region of diminishing plasma density. These detections are important in understanding the auroral processes occurring at Saturn. Recent efforts have focused on integrating RPWS data with that from other instruments, particularly from the CAPS-ELS investigation. Electron beams are known to be the source of auroral hiss emission at Earth, and it is generally believed the same is true at Saturn. Current work has focused on correlating these beams with the observed radio emission, along with modeling the beams to calculate their growth rates. One electron beam has already been analyzed from the high-latitude pass on October 17, 2008. This beam was determined to be propagating upward from Saturn, and has been found to produce a large whistler-mode growth rate, which fits with the auroral hiss model. More electron beams will be analyzed in this fashion over the coming months. These results will be the focus of this presentation.

  12. Dark auroral oval on saturn discovered in hubble space telescope ultraviolet images.

    PubMed

    Jaffel, L B; Leers, V; Sandel, B R

    1995-08-18

    Hubble Space Telescope ultraviolet images of Saturn obtained with the Faint Object Camera near 220 nanometers reveal a dark oval encircling the north magnetic pole of the planet. The opacity has an equivalent width of approximately 11 degrees in latitude and is centered around approximately 79 degrees N. The oval shape of the dark structure and its coincidence with the aurora detected by the Voyager Ultraviolet Spectrometer suggest that the aerosol formation is related to the auroral activity.

  13. Joseph Henry and John Henry Lefroy A common 19th century vision of auroral research

    NASA Astrophysics Data System (ADS)

    Silverman, S. M.

    Research on solar-terrestrial relationships today relies primarily on in situ space data. These data, however, cover only a short period of about 30 years. Many solar and related phenomena vary on much longer time scales. For the study of these, parameters such as sunspots, magnetic activity, auroral occurrence, or other proxy data are required. Historical records of aurora are particularly useful in this connection.

  14. Near-IR Auroral Processes in the Polar Regions of Jupiter

    NASA Astrophysics Data System (ADS)

    Kim, S. J.

    2011-10-01

    Recently, 3 micron auroral emission lines of CH4, C2H2, and C2H6 from the south polar auroral region of Jupiter were detected [1]. In order to understand the auroral processes producing these emissions, we constructed an electron precipitation model for the auroral atmosphere including H2, He, H, and the hydrocarbon molecules. We present preliminary results for the mixing ratios of these molecules in the stratosphere, which are consistent with the observed auroral emission intensities.

  15. Sophus Peter Tromholt: an outstanding pioneer in auroral research

    NASA Astrophysics Data System (ADS)

    Moss, K.; Stauning, P.

    2012-03-01

    The Danish school teacher Sophus Peter Tromholt (1851-1896) was self-taught in physics, astronomy, and auroral sciences. Still, he was one of the brightest auroral researchers of the 19th century. He was the first scientist ever to organize and analyse correlated auroral observations over a wide area (entire Scandinavia) moving away from incomplete localized observations. Tromholt documented the relation between auroras and sunspots and demonstrated the daily, seasonal and solar cycle-related variations in high-latitude auroral occurrence frequencies. Thus, Tromholt was the first ever to deduce from auroral observations the variations associated with what is now known as the auroral oval termed so by Khorosheva (1962) and Feldstein (1963) more than 80 yr later. He made reliable and accurate estimates of the heights of auroras several decades before this important issue was finally settled through Størmer's brilliant photographic technique. In addition to his three major scientific works (Tromholt, 1880a, 1882a, and 1885a), he wrote numerous short science notes and made huge efforts to collect historical auroral observations (Tromholt, 1898). Furthermore, Tromholt wrote a large number of popular science articles in newspapers and journals and made lecture tours all over Scandinavia and Germany, contributing to enhance the public educational level and awareness. He devoted most of his life to auroral research but as a self-taught scientist, he received little acclaim within the contemporary academic scientific society. With his non-academic background, trained at a college of education - not a university - he was never offered a position at a university or a research institution. However, Sophus Tromholt was an outstanding pioneer in auroral research.

  16. Correlated pulsations in auroral light intensity and VLF hiss

    NASA Astrophysics Data System (ADS)

    Duthie, D. D.; Rash, J. P. S.; Scourfield, M. W. J.

    1985-12-01

    Observations at Sanae, Antarctica of a pulsating aurora with a low light level TV system have been combined with simultaneous recordings of VLF hiss on a broad band receiver. Both auroral light and hiss intensities display a significant peak at 1.3 Hz in the power spectrum. The peaks in the auroral light intensity variations lead those in the VLF hiss by times between zero and 0.2 s, as revealed by cross-spectral analysis. These results are explained in terms of cyclotron resonance in the equatorial plane between the auroral electrons and echoing VLF hiss.

  17. Magnetospheric and auroral plasmas - A short survey of progress

    NASA Technical Reports Server (NTRS)

    Frank, L. A.

    1975-01-01

    Important milestones in our researches of auroral and magnetospheric plasmas for the past quadrennium 1971-1975 are reviewed. Many exciting findings, including those of the polar cusp, the polar wind, the explosive disruptions of the magnetotail, the interactions of hot plasmas with the plasmapause, the auroral field-aligned currents, and the striking inverted V electron precipitation events, were reported during this period. Solutions to major questions concerning the origins and acceleration of these plasmas appear possible in the near future. A comprehensive bibliography of current research is appended to this brief survey of auroral and magnetospheric plasmas.

  18. 10 CFR 1042.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Education programs or activities. 1042.400 Section 1042... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1042.400 Education programs or activities....

  19. 10 CFR 1042.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Education programs or activities. 1042.400 Section 1042... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1042.400 Education programs or activities....

  20. 10 CFR 1042.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Education programs or activities. 1042.400 Section 1042... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1042.400 Education programs or activities....

  1. 10 CFR 1042.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Education programs or activities. 1042.400 Section 1042... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1042.400 Education programs or activities....

  2. Mesoscale ionospheric tomography at the Auroral region

    NASA Astrophysics Data System (ADS)

    Luntama, J.; Kokkatil, G. V.

    2008-12-01

    FMI (Finnish Meteorological Institute) has used observations from the dense GNSS network in Finland for high resolution regional ionospheric tomography. The observation system used in this work is the VRS (Virtual Reference Station) network in Finland operated by Geotrim Ltd. This network contains 86 GNSS ground stations providing two frequency GPS and GLONASS observations with the sampling rate of 1 Hz. The network covers the whole Finland and the sampling of the ionosphere is very good for observing mesoscale ionospheric structures at the Auroral region. The ionospheric tomography software used by FMI is the MIDAS (Multi-Instrument Data Analysis System) algorithm developed and implemented by the University of Bath (Mitchell and Spencer, 2003). MIDAS is a 3-D extension of the 2-D tomography algorithm originally presented by Fremouw et al. (1992). The research at FMI is based on ground based GNSS data collected in December 2006. The impacts of the two geomagnetic storms during the month are clearly visible in the retrieved electron density and TEC maps and they can be correlated with the magnetic field disturbances measured by the IMAGE magnetometer network. This is the first time that mesoscale structures in the ionospheric plasma can be detected from ground based GNSS observations at the Auroral region. The continuous high rate observation data from the Geotrim network allows monitoring of the temporal evolution of these structures throughout the storms. Validation of the high resolution electron density and TEC maps is a challenge as independent reference observations with a similar resolution are not available. FMI has compared the 3-D electron density maps against the 2-D electron density plots retrieved from the observations from the Ionospheric Tomography Chain operated by the Sodankylä Geophysical Observatory (SGO). Additional validation has been performed with intercomparisons with observations from the ground based magnetometer and auroral camera network

  3. Current Closure in the Auroral Ionosphere: Results from the Auroral Current and Electrodynamics Structure Rocket Mission

    NASA Technical Reports Server (NTRS)

    Kaeppler, S. R.; Kletzing, C. A.; Bounds, S. R.; Gjerloev, J. W.; Anderson, B. J.; Korth, H.; LaBelle, J. W.; Dombrowski, M. P.; Lessard, M.; Pfaff, R. F.; Rowland, D. E.; Jones, S.; Heinselman, C. J.

    2011-01-01

    The Auroral Current and Electrodynamics Structure (ACES) mission consisted of two sounding rockets launched nearly simultaneously from Poker Flat Research Range, AK on January 29, 2009 into a dynamic multiple-arc aurora. The ACES rocket mission was designed to observe electrodynamic and plasma parameters above and within the current closure region of the auroral ionosphere. Two well instrumented payloads were flown along very similar magnetic field footprints, at different altitudes, with small temporal separation between both payloads. The higher altitude payload (apogee 360 km), obtained in-situ measurements of electrodynamic and plasma parameters above the current closure region to determine the input signature. The low altitude payload (apogee 130 km), made similar observations within the current closure region. Results are presented comparing observations of the electric fields, magnetic components, and the differential electron energy flux at magnetic footpoints common to both payloads. In situ data is compared to the ground based all-sky imager data, which presents the evolution of the auroral event as the payloads traversed through magnetically similar regions. Current measurements derived from the magnetometers on the high altitude payload observed upward and downward field-aligned currents. The effect of collisions with the neutral atmosphere is investigated to determine it is a significant mechanism to explain discrepancies in the low energy electron flux. The high altitude payload also observed time-dispersed arrivals in the electron flux and perturbations in the electric and magnetic field components, which are indicative of Alfven waves.

  4. Current Closure in the Auroral Ionosphere: Results from the Auroral Current and Electrodynamics Structure Rocket Mission

    NASA Technical Reports Server (NTRS)

    Kaeppler, S. R.; Kletzing, C. A.; Bounds, S. R.; Gjerloev, J. W.; Anderson, B. J.; Korth, H.; LaBelle, J. W.; Dombrowski, M. P.; Lessard, M.; Pfaff, R. F.; Rowland D. E.; Jones, S.; Heinselman, C. J.

    2012-01-01

    The Auroral Current and Electrodynamics Structure (ACES) mission consisted of two sounding rockets launched nearly simultaneously from Poker Flat Research Range, AK on January 29, 2009 into a dynamic multiple-arc aurora. The ACES rocket mission was designed to observe electrodynamic and plasma parameters above and within the current closure region of the auroral ionosphere. Two well instrumented payloads were flown along very similar magnetic field footprints, at different altitudes, with small temporal separation between both payloads. The higher altitude payload (apogee 360 km), obtained in-situ measurements of electrodynamic and plasma parameters above the current closure region to determine the input signature. The low altitude payload (apogee 130 km), made similar observations within the current closure region. Results are presented comparing observations of the electric fields, magnetic components, and the differential electron energy flux at magnetic footpoints common to both payloads. In situ data is compared to the ground based all-sky imager data, which presents the evolution of the auroral event as the payloads traversed through magnetically similar regions. Current measurements derived from the magnetometers on the high altitude payload observed upward and downward field-aligned currents. The effect of collisions with the neutral atmosphere is investigated to determine if it is a significant mechanism to explain discrepancies in the low energy electron flux. The high altitude payload also observed time-dispersed arrivals in the electron flux and perturbations in the electric and magnetic field components, which are indicative of Alfven waves.

  5. Auroral observations in the Antarctic at the time of the Tunguska event, 1908 June 30.

    NASA Astrophysics Data System (ADS)

    Steel, D.; Ferguson, R.

    1993-03-01

    The original notebooks of Sir Douglas Mawson containing observations of the aurora australis by members of the British Antarctic Expedition at the time of the Tunguska explosion over Siberia on 1908 June 30 have been inspected, and it is found that, contrary to some suggestions which note that geomagnetic transients were witnessed elsewhere, and that the BAE was in winter quarters close to the south magnetic pole at the time, no exceptional auroral activity was seen which might have provided useful information on a planet-wide disturbance at the time of the event. However, an exceptional aurora was seen about seven hours prior to the explosion, and it is suggested that this may have been due to an anti-solar comet-like ion tail producing that auroral display whilst the impactor was still far from Earth.

  6. Intensity of the auroral electrojets during a recovery phase of magnetic storm

    NASA Astrophysics Data System (ADS)

    Boroyev, R. N.

    2016-06-01

    In this work, the effect of solar wind velocity on the development of magnetospheric and ionospheric disturbances is studied. It is shown that at high velocity of the solar wind during a recovery phase of magnetic storm the strong auroral activity characterized by the AE index is observed. In some cases during a recovery phase of magnetic storm the value of AE index is practically comparable with the value of AE index observed during the main phase of magnetic storm. When comparing time intervals of two magnetic storms during which the values of solar wind electric fields are approximately equal to each other, it is found that auroral electrojet intensity is stronger in that storm in which the solar wind velocity is higher.

  7. Observations of the auroral hectometric radio emission onboard the INTERBALL-1 satellite

    NASA Astrophysics Data System (ADS)

    Kuril'Chik, V. N.

    2007-06-01

    The results of five-year (1995 2000) continuous observations of the auroral radio emission (ARE) in the hectometric wavelength range on the high-apogee INTERBALL-1 satellite are presented. Short intense bursts of the auroral hectometric radio emission (AHR) were observed at frequencies of 1463 and 1501 kHz. The bursts were observed predominantly at times when the terrestrial magnetosphere was undisturbed (in the quiet Sun period), and their number decreased rapidly with increasing solar activity. The bursts demonstrated seasonal dependence in the Northern and Southern hemispheres (dominating in the autumn-winter period). Their appearance probably depends on the observation time (UT). A qualitative explanation of the AHR peculiarities is given.

  8. Auroral spectrum between 1200 and 4000 angstroms.

    NASA Technical Reports Server (NTRS)

    Sharp, W. E.; Rees, M. H.

    1972-01-01

    Results of spectroscopic observations of an auroral event made simultaneously by airborne and satellite-borne scanning spectrometers in the wavelength region between 1200 and 4000 A. Photon emission rates of several vibrational bands of the N2, 2nd positive, Vegard-Kaplan, and Lyman-Birge-Hopfield systems, the N I lines at 1200 and 3466 A, and O I lines at 1304, 1356, and 2972 A were recorded. Model calculations of the emission rates of the observed features are found to be in reasonable agreement with the measurements. Electron impact excites the nitrogen band systems, as well as the O I 1356-A line. A spectral feature at 2150 A is tentatively identified as the (1, 0) gamma band of N O.

  9. Automatic Georeferencing of Astronaut Auroral Photography

    NASA Astrophysics Data System (ADS)

    Walsh, A. P.; Riechert, M.; Taylor, M. G.

    2014-12-01

    Astronauts on board the International Space Station have taken thousands of high quality photographs of the aurorae borealis and australis with a high temporal and spatial resolution. A barrier to these photographs being used in research is that the cameras do not have a fixed orientation and the images therefore do not have any pointing information associated with them. Using astrometry.net and other open source libraries we have developed a software toolkit to automatically reconstruct the pointing of the images from the visible starfield and hence project the auroral images in geographic and geomagnetic coordinates. Here we explain the technique and the resulting data products, which will soon be publically available through the project website.

  10. An anomalous component of Neptune radio emission - Implications for the auroral zone

    NASA Astrophysics Data System (ADS)

    Desch, M. D.; Farrell, W. M.; Kaiser, M. L.

    1991-02-01

    The Voyager planetary radio astronomy experiment detected a bursty, narrow-band radio emission originating in Neptune's magnetosphere. The time of occurrence of nearly all of the episodes of this bursty radio emission can be explained on the basis of a radio source located just above and to the east of the south magnetic offset tilted dipole (OTD) tip (Farrell et al., 1990). However, several episodes of bursty emission do not occur at the usual frequency and planetaray rotation phase for emissions of this type. The occurrences of these rarely seen anomalous episodes are shifted systematically in planetary longitude so as to be consistent with a source of emission to the southwest of the southern magnetic OTD pole. Owing to the proximity of these sources to the magnetic polar region, they are associated with an active auroral region. Therefore, at least from the standpoint of the radio emission, the picture that emerges is of an auroral zone with two emission hot spots approximately diametrically east and west of the south magnetic pole. The possibility of a complete radio-active auroral oval is discussed.

  11. Propagation of a westward traveling surge and the development of persistent auroral features

    SciTech Connect

    Craven, J.D.; Frank, L.A.; Akasofu, S.I.

    1989-01-01

    Imaging instrumentation on board the spacecraft Dynamics Explorer 1 (DE 1) is used to observe the large-scale motion of a surge over 7000 km along the auroral oval from near local midnight. Average speed of the surge is 2.2 km/s. Ground-based observations at Fort Yukon, Alaska, show the classical looped, multiple-arc structure of a westward traveling surge as it passes overhead. Within the 6-min temporal resolution provide with DE 1, the surge advances initially at a speed of about 8 km.s followed by a steady decline to about 1 km/s over a period of 17 min. This sequence is then repeated a second time, beginning with a significant intensification of the surge form. This intense surge activity is not accompanied by significant auroral activity near magnetic midnight. Following passage of the surge, persistent and localized bright emission regions remain along the auroral oval for several tens of minutes. Average separation distances are approximately 700 km. If these persistent features identify the sites of individual stepwise advances of the surge, the average time per advance is about 5 min.

  12. Intensification and fading of auroral arcs in the dusk-midnight sector of the polar cap

    SciTech Connect

    Wu, Q.; Rosenberg, T.J. ); Berkey, F.T. ); Eather, R.H. )

    1991-05-01

    Observations of the aurora from South Pole station (magnetic latitude = {minus}74.2{degree}) have been used to study the intensification and fading of polar arcs observed near the dusk meridian. Most of the cases examined have the following features in common: (1) a preexisting auroral form intensifies for about 10 min; (2) this activation is followed by a pronounced decrease of luminosity; (3) the auroral fade terminates after 30-60 min with the onset of intense aurora which sweeps rapidly overhead. The availability of all-sky camera, auroral electrojet (AE) index and interplanetary magnetic field (IMF) data for some of the cases enables the following additional characterizations of these events. The preexisting form is a Sun- or oval-aligned arc (or part of a multiple arc system) which disappears following the activation; equatorward drift of the arc (or system) accompanies the luminosity change. There is some evidence to suggest that the arc is poleward of the auroral oval. The brief intensification and/or the onset of fading occurs during the growth phase or near the start of the expansive phase of a substorm; termination of the fade is near the maximum in AE and is probably indicative of the beginning of the recovery phase of the substorm. For all three cases for which IMF data were available the onset of fading occurred 20-30 min after B{sub z} turned southward. Sun-aligned arcs are a common feature of the polar cap during northward B{sub z} but disappear during the increasingly disturbed conditions that accompany southward B{sub z}. The present results suggest that brief intensifications of southern hemisphere polar cap arcs near dusk may be linked in part to the sunward orientation of the IMF which favors enhanced electron fluxes in the southern lobe of the magnetotail.

  13. Towards a synthesis of substorm electrodynamics: HF radar and auroral observations

    NASA Astrophysics Data System (ADS)

    Grocott, A.; Lester, M.; Parkinson, M. L.; Yeoman, T. K.; Dyson, P. L.; Devlin, J. C.; Frey, H. U.

    2006-12-01

    At 08:35 UT on 21 November 2004, the onset of an interval of substorm activity was captured in the southern hemisphere by the Far UltraViolet (FUV) instrument on board the IMAGE spacecraft. This was accompanied by the onset of Pi2 activity and subsequent magnetic bays, evident in ground magnetic data from both hemispheres. Further intensifications were then observed in both the auroral and ground magnetic data over the following ~3 h. During this interval the fields-of-view of the two southern hemisphere Tasman International Geospace Enviroment Radars (TIGER) moved through the evening sector towards midnight. Whilst initially low, the amount of backscatter from TIGER increased considerably during the early stages of the expansion phase such that by ~09:20 UT an enhanced dusk flow cell was clearly evident. During the expansion phase the equatorward portion of this flow cell developed into a narrow high-speed flow channel, indicative of the auroral and sub-auroral flows identified in previous studies (e.g. Freeman et al., 1992; Parkinson et al., 2003). At the same time, higher latitude transient flow features were observed and as the interval progressed the flow reversal region and Harang discontinuity became very well defined. Overall, this study has enabled the spatial and temporal development of many different elements of the substorm process to be resolved and placed within a simple conceptual framework of magnetospheric convection. Specifically, the detailed observations of ionospheric flows have illustrated the complex interplay between substorm electric fields and associated auroral dynamics. They have helped define the distinct nature of different substorm current systems such as the traditional substorm current wedge and the more equatorward currents associated with polarisation electric fields. Additionally, they have revealed a radar signature of nightside reconnection which provides the promise of quantifying nightside reconnection in a way which has

  14. Active Sites Environmental Monitoring Program: Action levels

    SciTech Connect

    Ashwood, J.S.; Ashwood, T.L.

    1991-10-01

    The Active Sites Environmental Monitoring Program (ASEMP) was established at Oak Ridge National Laboratory to provide for early leak detection and to monitor performance of the active low-level waste disposal facilities in Solid Waste Storage Area (SWSA) 6 and the transuranic waste storage areas in SWSA 5 North. Early leak detection is accomplished by sampling runoff, groundwater, and perched water in burial trenches. Sample results are compared to action levels that represent background contamination by naturally occurring and fallout-derived radionuclides. 15 refs., 3 figs., 12 tabs.

  15. Active Sites Environmental Monitoring Program: Program plan. Revision 1

    SciTech Connect

    Ashwood, T.L.; Wickliff, D.S.; Morrissey, C.M.

    1992-02-01

    The Active Sites Environmental Monitoring Program (ASEMP), initiated in 1989, provides early detection and performance monitoring of transuranic (TRU) waste and active low-level waste (LLW) facilities at Oak Ridge National Laboratory (ORNL) in accordance with US Department of Energy (DOE) Order 5820.2A. Active LLW facilities in Solid Waste Storage Area (SWSA) 6 include Tumulus I and Tumulus II, the Interim Waste Management Facility (IWMF), LLW silos, high-range wells, asbestos silos, and fissile wells. The tumulus pads and IWMF are aboveground, high-strength concrete pads on which concrete vaults containing metal boxes of LLW are placed; the void space between the boxes and vaults is filled with grout. Eventually, these pads and vaults will be covered by an engineered multilayered cap. All other LLW facilities in SWSA 6 are below ground. In addition, this plan includes monitoring of the Hillcut Disposal Test Facility (HDTF) in SWSA 6, even though this facility was completed prior to the data of the DOE order. In SWSA 5 North, the TRU facilities include below-grade engineered caves, high-range wells, and unlined trenches. All samples from SWSA 6 are screened for alpha and beta activity, counted for gamma-emitting isotopes, and analyzed for tritium. In addition to these analytes, samples from SWSA 5 North are analyzed for specific transuranic elements.

  16. A multi-instrument study of auroral hiss at Saturn

    NASA Astrophysics Data System (ADS)

    Kopf, Andrew James

    2010-11-01

    Over the last fifty years, a multitude of spacecraft and rocket experiments have studied plasma wave emissions from Earth's auroral regions. One such emission is auroral hiss, a low-frequency whistler-mode wave that is produced in the auroral zone. Observations from Earth-orbiting spacecraft show that auroral hiss is generated by field-aligned electron beams, with the resulting plasma wave emission propagating along the resonance cone. This propagation results in auroral hiss appearing as a V-shaped funnel when observed on a frequency-time spectrogram. This thesis presents the first comprehensive study of auroral hiss at a planet other than Earth, using the Cassini spacecraft to study auroral hiss at Saturn. NASA's Cassini spacecraft, currently in orbit around Saturn, has allowed for the first opportunity to study this emission in detail at another planet. Since 2006, the Cassini spacecraft has twice been in a series of high inclination orbits, allowing investigation and measurements of Saturnian auroral phenomena. During this time, the Radio and Plasma Wave Science (RPWS) Investigation on Cassini detected low frequency whistler mode emissions propagating upward along the auroral field lines, much like terrestrial auroral hiss. Comparisons of RPWS data with observations from several other Cassini instruments, including the Dual-Technique Magnetometer (MAG), Magnetospheric Imaging Instrument (MIMI), and the Cassini Plasma Spectrometer (CAPS), have revealed a complete picture of this emission at Saturn. Observations from these instruments have been used to make a variety of determinations about auroral hiss at Saturn. RPWS has only observed this emission when Cassini was at high-latitudes, although these observations have shown no preference for local time. Tracking the times this emission has been observed revealed a clear periodicity in the emission. Further study later revealed not one but two rotational modulations, one in each hemisphere, rotating at rates of

  17. Mirror instability and origin of morningside auroral structure

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Schulz, M.; Fennell, J. F.; Kishi, A. M.

    1983-01-01

    Auroral optical imagery shows marked differences between auroral features of the evening and morning sectors: the separation between diffuse and discrete auroras in the evening sector is not distinct in the morning sector, which is dominated by auroral patches and multiple banded structures aligned along some direction. Plasma distribution function signatures also show marked differences: downward electron beams and inverted-V signatures prefer the evening sector, while the electron spectra on the morning sector are similar to the diffuse aurora. A theory of morningside auroras consistent with these features was constructed. The theory is based on modulation of the growth rates of electron cyclotron waves by the mirror instability, which is in turn driven by inward-convected ions that have become anisotropic. This modulation produces alternating bands of enhanced and reduced electron precipitation which approximate the observed multiple auroral bands and patches of the morning sector.

  18. Analytic model of aurorally coupled magnetospheric and ionospheric electrostatic potentials

    NASA Astrophysics Data System (ADS)

    Cornwall, John M.

    1993-09-01

    This paper describes modest but significant improvements on earlier studies of electrostatic potential structure in the auroral region, using the adiabatic auroral arc model. With certain simplifying assumptions, new analytic nonlinear solutions fully exhibiting the parametric dependence of potentials on magnetospheric (e.g., cross-tail potential) and ionospheric (e.g., recombination rate) parameters are found. No purely phenomenological parameters are introduced. The results are in reasonable agreement with observed average auroral potential drops, inverted-V scale sizes, and dissipation rates. The dissipation rate is quite comparable to tail energization and transport rates and should have a major effect on tail and magnetospheric dynamics. Various relations between the cross-tail potential and auroral parameters (e.g., total parallel currents and potential drops) are given which can be studied with existing data sets.

  19. Field-aligned particle currents near an auroral arc.

    NASA Technical Reports Server (NTRS)

    Choy, L. W.; Arnoldy, R. L.; Potter, W.; Kintner, P.; Cahill, L. J., Jr.

    1971-01-01

    A Nike-Tomahawk rocket equipped to measure electric and magnetic fields and charged particles from a few eV to several hundred keV energy was flown into an auroral band on April 11, 1970. The purpose of this flight was to obtain evidence of the low-energy electrons and protons that constitute a field-aligned sheet current, and also to obtain the magnetic signature of such a current and the electric field in and near the auroral-arc electric current system. Particular attention was given to a sudden increase in the field-aligned current associated with a prior sudden increase in the electric field and a sudden change in the magnetic field, all occurring near the edge of a visual auroral arc. Data obtained are discussed and analyzed; they present an important contribution to the problem of mapping of atmospheric auroral phenomena to the magnetospheric equatorial plane.

  20. Auroral-clutter predictions for Fylingdales, England. Interim report

    SciTech Connect

    Tsunoda, R.T.

    1991-07-01

    Radar clutter produced by auroral processes in the ionospheric E layer, called auroral clutter, can have severe deleterious effects on surveillance radars that operate in the subauroral regions. Auroral clutter characteristics, however, are practically impossible to characterize with a statistical description because of the large number of controlling parameters. Recently, a predictive code called Comprehensive E-Region Auroral Clutter (CERAC) model has been written that used knowledge of the underlying physics and semiempirical data as its basis. This is a description of the predictions of the CERAC model for a surveillance radar located at Fylingdales, England. The results include predictions of occurrence, radar cross section, and Doppler velocity, all as functions of radar elevation, azimuth, range, and time.

  1. Mirror instability and the origin of morningside auroral structure

    SciTech Connect

    Chiu, Y.T.; Schulz, M.; Fennell, J.F.; Kishi, A.M.

    1983-05-01

    Auroral optical imagery shows marked differences between auroral features of the evening and morning sectors: The separation between diffuse and discrete auroras in the evening sector is not distinct in the morning sector, which is dominated by auroral patches and multiple banded structures aligned along some direction. Plasma distribution function signatures also show marked differences: downward electron beams and inverted-V signatures prefer the evening sector, while the electron spectra on the morning sector are similar to the diffuse aurora. We have constructed a theory of morningside auroras consistent with these features. The theory is based on modulation of the growth rates of electron cyclotron waves by the mirror instability, which is in turn driven by inward-convected ions that have become anisotropic. This modulation produces alternating bands of enhanced and reduced electron precipitation which approximate the observed multiple auroral bands and patches of the morning sector.

  2. Interactive Auroral Science for Hearing-Impaired Students

    NASA Astrophysics Data System (ADS)

    Samara, M.; Michell, R. G.; Jahn, J.; Pfeifer, M.; Ibarra, S.; Hampton, D. L.; Powell, D.

    2012-12-01

    Under a NASA E/PO grant, we have partnered with San Antonio's Sunshine Cottage School for Deaf Children to develop a science class experience where students directly interact with scientists and participate in a research-grade space science measurement campaign. The unique aspect of partnering with Sunshine Cottage lies in Sunshine's approach of auditory-verbal communication. Aided by technology (hearing aids, cochlear implants), a diverse student body with students of all levels of hearing loss (moderate through profound) is taught in an entirely auditory-verbal environment at Sunshine Cottage. Bringing these students into early contact with research work can lay the foundation for future careers in the STEM field that normally they might not consider as indicated by the first year of this collaboration where the student response was distinctly positive. Here we report on the first year of those activities, as they related to a ground based imaging approach to exploring the northern lights and from the point of view of the scientists that participated. The major components of that activity included a site visit to SwRI by the students and their teachers, a semester long lab at school utilizing current research tools and a real-time campaign night. The students used a number of diagnostics to first predict and then verify auroral activity. One of the tools used was the MOOSE observatory which is a community resource state of the art observatory comprised of 5 EMCCD imagers in Alaska, established through an NSF MRI grant. We will discuss the approach and lessons learned during the first year of the project and the directions that we will likely take in the second year. Lessons learned from teaching these students space science related topic can be flowed right back into mainstream classroom settings. One other significant and unexpected aspect of this first year was that we were able to connect two groups of students through skype (in the 4th to 5th grades) that

  3. School-Age Ideas and Activities for After School Programs.

    ERIC Educational Resources Information Center

    Haas-Foletta, Karen; Cogley, Michele

    This guide describes activities for school-age children in after-school day care programs. These activities may also be used in other settings. An introductory section discusses program philosophy, room arrangement, multicultural curriculum, program scheduling, summer programs and holiday care, field trips and special programs, age grouping,…

  4. Auroral magnetosphere-ionosphere coupling: A brief topical review

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Schulz, M.; Cornwall, J. M.

    1979-01-01

    Auroral arcs result from the acceleration and precipitation of magnetospheric plasma in narrow regions characterized by strong electric fields both perpendicular and parallel to the earth's magnetic field. The various mechanisms that were proposed for the origin of such strong electric fields are often complementary Such mechanisms include: (1) electrostatic double layers; (2) double reverse shock; (3) anomalous resistivity; (4) magnetic mirroring of hot plasma; and (5) mapping of the magnetospheric-convection electric field through an auroral discontinuity.

  5. 31 CFR 28.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Education programs or activities. 28... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 28.400 Education programs...

  6. 41 CFR 101-4.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 2 2013-07-01 2012-07-01 true Education programs or... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 101-4.400 Education programs or activities....

  7. 43 CFR 41.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Education programs or activities. 41.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 41.400 Education programs...

  8. 22 CFR 229.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Education programs or activities. 229.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 229.400 Education programs or...

  9. 43 CFR 41.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Education programs or activities. 41.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 41.400 Education programs...

  10. 45 CFR 618.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Education programs or activities. 618.400 Section... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 618.400 Education programs...

  11. 22 CFR 146.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Education programs or activities. 146.400... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 146.400 Education programs or...

  12. 40 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Education programs or activities. 5.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 5.400 Education programs...

  13. 22 CFR 229.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Education programs or activities. 229.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 229.400 Education programs or...

  14. 40 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Education programs or activities. 5.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 5.400 Education programs...

  15. 15 CFR 8a.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Education programs or activities. 8a... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 8a.400 Education programs...

  16. 31 CFR 28.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Education programs or activities. 28... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 28.400 Education programs...

  17. 15 CFR 8a.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Education programs or activities. 8a... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 8a.400 Education programs...

  18. 22 CFR 146.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Education programs or activities. 146.400... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 146.400 Education programs or...

  19. 28 CFR 54.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Education programs or activities. 54.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 54.400 Education programs or...

  20. 22 CFR 229.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Education programs or activities. 229.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 229.400 Education programs or...

  1. 15 CFR 8a.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Education programs or activities. 8a... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 8a.400 Education programs...

  2. 31 CFR 28.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Education programs or activities. 28... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 28.400 Education programs...

  3. 45 CFR 86.31 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Education programs or activities. 86.31 Section 86... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 86.31 Education programs...

  4. 45 CFR 618.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Education programs or activities. 618.400 Section... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 618.400 Education programs...

  5. 28 CFR 54.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Education programs or activities. 54.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 54.400 Education programs or...

  6. 6 CFR 17.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 6 Domestic Security 1 2012-01-01 2012-01-01 false Education programs or activities. 17.400 Section... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 17.400 Education programs...

  7. 40 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Education programs or activities. 5.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 5.400 Education programs...

  8. 43 CFR 41.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Education programs or activities. 41.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 41.400 Education programs...

  9. 49 CFR 25.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 false Education programs or activities. 25.400 Section... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 25.400 Education programs or...

  10. 22 CFR 146.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Education programs or activities. 146.400... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 146.400 Education programs or...

  11. 41 CFR 101-4.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 2 2012-07-01 2012-07-01 false Education programs or... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 101-4.400 Education programs or activities....

  12. 6 CFR 17.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 6 Domestic Security 1 2013-01-01 2013-01-01 false Education programs or activities. 17.400 Section... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 17.400 Education programs...

  13. 6 CFR 17.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 6 Domestic Security 1 2014-01-01 2014-01-01 false Education programs or activities. 17.400 Section... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 17.400 Education programs...

  14. 41 CFR 101-4.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 2 2014-07-01 2012-07-01 true Education programs or... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 101-4.400 Education programs or activities....

  15. 49 CFR 25.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 false Education programs or activities. 25.400 Section... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 25.400 Education programs or...

  16. 41 CFR 101-4.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Education programs or... EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 101-4.400 Education programs or activities....

  17. 22 CFR 146.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Education programs or activities. 146.400... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 146.400 Education programs or...

  18. 43 CFR 41.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Education programs or activities. 41.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 41.400 Education programs...

  19. 45 CFR 86.31 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Education programs or activities. 86.31 Section 86... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 86.31 Education programs...

  20. 6 CFR 17.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 6 Domestic Security 1 2010-01-01 2010-01-01 false Education programs or activities. 17.400 Section... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 17.400 Education programs...

  1. 49 CFR 25.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Education programs or activities. 25.400 Section... IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 25.400 Education programs or...

  2. 15 CFR 8a.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Education programs or activities. 8a... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 8a.400 Education programs...

  3. 40 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Education programs or activities. 5.400... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 5.400 Education programs...

  4. 22 CFR 229.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Education programs or activities. 229.400... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 229.400 Education programs or...

  5. 31 CFR 28.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Education programs or activities. 28... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 28.400 Education programs...

  6. 45 CFR 618.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Education programs or activities. 618.400 Section... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 618.400 Education programs...

  7. The source of Jovian auroral hiss observed by Voyager 1

    NASA Technical Reports Server (NTRS)

    Morgan, D. D.; Gurnett, D. A.; Kurth, W. S.; Bagenal, F.

    1994-01-01

    Observations of auroral hiss obtained from the Voyager 1 encounter with Jupiter have been reanalyzed. The Jovian auroral hiss was observed near the inner boundary of the warm Io torus and has a low-frequency cutoff caused by propagation near the resonance cone. A simple ray tracing procedure using an offset tilted dipole of the Jovian magnetic field is used to determine possible source locations. The results obtained are consistent with two sources located symmetrically with respect to the centrifugal equator along an L shell (L approximately = 5.59) that is coincident with the boundary between the hot and cold regions of the Io torus and is located just inward of the ribbon feature observed from Earth. The distance of the sources from the centrifugal equator is approximately 0.58 +/- 0.01 R(sub J). Based on the similarity to terrestrial auroral hiss, the Jovian is auroral hiss is believed to be generated by beams of low energy (approximately tens to thousands of eV) electrons. The low-frequency cutoff of the auroral hiss suggests that the electrons are accelerated near the inferred source region, possibly by parallel electric fields similar to those existing in the terrestrial auroral regions. A field-aligned current is inferred to exist at L shells just inward of the plasma ribbon. A possible mechanism for driving this current is discussed.

  8. Jupiter's equatorward auroral features: Possible signatures of magnetospheric injections

    NASA Astrophysics Data System (ADS)

    Dumont, M.; Grodent, D.; Radioti, A.; Bonfond, B.; Gérard, J.-C.

    2014-12-01

    The present study investigates the characteristics of ultraviolet auroral features located equatorward of the main emission appearing in Hubble Space Telescope images of the northern and southern Jovian hemispheres obtained in 2000-2007. On average, one feature is observed every day, but several auroral structures are occasionally seen over a wide range of local times in the same image. Several properties of these features are analyzed, such as their location, emitted power, and lifetime. Additionally, we magnetically map the auroral features to the equatorial plane using the VIPAL model in order to compare their observed properties with those of magnetospheric injections detected by the Galileo spacecraft. The equatorward auroral features show up between the Io footpath and the main auroral emission, at all System III longitudes, in agreement with Galileo measurements. Moreover, we compare the magnetic flux associated with these features with estimates of the outgoing flux related to the radial transport of plasma in the Jovian magnetosphere, and we find that they could account for at least one third of this flux. This comparative study shows that the auroral features under study are most probably related to magnetospheric injections and thus sheds light on the processes involved in the magnetosphere-ionosphere dynamics.

  9. Ionospheric heating, upwelling, and depletions in auroral current systems

    NASA Astrophysics Data System (ADS)

    Zettergren, M. D.; Semeter, J. L.

    2010-12-01

    This research investigates aspects of ionospheric dynamics relevant to magnetosphere-ionosphere coupling in auroral arc current systems. Auroral electric fields and particle precipitation deposit energy in the ionosphere, often resulting in enhanced ion or electron temperatures. This heating has a wide variety of consequences for the ionosphere. High ion temperatures alter chemical balance in the lower F-region, resulting in conversion to a molecular ion plasma, faster recombination, and plasma depletions. Pressure enhancements resulting from both ion and electron heating are capable of generating intense ion upflows. Ion upflow and depletion processes redistribute and structure the auroral plasma in ways that are likely of consequence to wave coupling of the magnetosphere and ionosphere. These implications are examined through the use of a fluid-kinetic model of the auroral ionosphere and new incoherent scatter radar data analysis techniques. Results indicate that enhanced recombination of molecular ions in auroral downward current regions may work in concert with well-known electrodynamic depletion processes, in the F-region ionosphere. Furthermore, ionospheric upflows in auroral upward and downward current regions may be quite different in terms of intensity and types of upflowing ions.

  10. Effect of auroral substorms on the ionospheric range spread-F enhancements at high southern midlatitudes using real time vertical-sounding ionograms

    NASA Astrophysics Data System (ADS)

    Hajkowicz, Lech A.

    2016-03-01

    A comprehensive study has been undertaken on the effect of magnetic substorm onsets (as deduced from the auroral hourly electrojet AE-index) on the occurrence of high midlatitude (or sub-auroral latitude) ionospheric range spread-F (Sr). Unlike the previous reports real-time ionograms were used in this analysis thus eliminating ambiguities stemming from the correlating secondary evidence of spread-F with auroral substorms. The Australian southernmost ionosonde station Hobart (51.6°S geom.) proved to be uniquely suitable for the task as being sufficiently close to the southern auroral zone. Sr was assigned in km to each hourly nighttime ionogram at two sounding frequencies: Sr1 (at 2 MHz) and Sr2 (at 6 MHz) for four months in 2002: January and June (representing southern summer and winter solstices), and March and September (representing autumn and vernal equinoxes). It is evident that the southern winter solstitial period (June) is associated with high endemic midlatitude spread-F activity. All other seasons are closely linked with temporal sequences of enhanced spread-F activity following substorm onsets. For the first time it was possible not only find a simultaneous occurrence pattern of these diverse phenomena but to deduce numerical characteristics of the response of midlatitude ionosphere to the global auroral stimulus. Excellent case events, hitherto unpublished, are shown illustrating the presence of the AE peaks (in nT) being ahead of Sr peaks (in km) by a time shift ∆t (in h). Sr1 magnitude showed a significant correlation with the magnitudes of the preceding AE with a correlation coefficient (r) of 0.51 (probability of the occurrence by chance less than 0.01). Sr2 peaks were more sensitive to auroral disturbances but were not correlated with the AE magnitude variations. The time shift (∆t) was on average 4 h with a standard deviation of 3 h. The general pattern in the occurrence of magnetic substorms and spread-F is very similar. A number of

  11. Study of AKR hollow pattern characteristics at sub-auroral regions

    NASA Astrophysics Data System (ADS)

    Boudjada, Mohammed Y.; Sawas, Sami; Galopeau, Patrick; Berthelier, Jean-Jacques; Schwingenschuh, Konrad

    2014-05-01

    The Earth's auroral kilometric radiation (AKR) is expected to exhibit a hollow pattern similar to that reported for the comparable emissions from Jupiter (e.g. Jovian decametric emissions - DAM). The hollow pattern is a hollow cone beam with apex at the point of AKR emission, axis tangent to the magnetic field direction, and an opening angle of the order of 80°. The properties of the hollow cone can be derived from the so-called dynamic spectrum which displays the radiation versus the observation time and the frequency. We analyze the auroral kilometric radiation recorded by the electric field experiment (ICE) onboard DEMETER micro-satellite. The dynamic spectra lead us to study the occurrence of the AKR recorded in the sub-auroral regions when the micro-satellite was at altitudes of about 700 km. We address in this contribution issues concerning the characteristics (occurrence, latitude and longitude) of the AKR hollow beam and their relations to the seasonal and solar activity variations.

  12. Coordinated ground and space measurements of an auroral surge over South Pole

    SciTech Connect

    Rosenberg, T.J.; Detrick, D.L.; Mizera, P.F.; Gorney, D.J.; Berkey, F.T.; Eather, R.H.; Lanzerotti, L.J.

    1987-10-01

    Coincident ground-based and satellite observations are presented of a premidnight auroral surge over Amundsen-Scott South Pole station. The set of near-simultaneous measurements provides an excellent opportunity to gain a more quantitative understanding of the nature of premidnight substorm activity at high geomagnetic latitudes. The surge produced a rapid onset of cosmic radio noise absorption at the station. On the polar-orbiting DMSP F6 spacecraft, intense X ray emissions with E>2 keV energy were imaged 1/sup 0/ to 2/sup 0/ magnetically equatorward of South Pole approximately 1 min prior to the peak of the absorption event. The spectrum of precipitating electrons determined from the X ray measurements could be characterized by an e-folding energy of approx.11 keV and is found to be adequate to account for the cosmic noise absorption and maximum auroral luminosity recorded at South Pole. Photometer, all-sky camera, riometer, and magnetometer data are used to estimate the velocity of motion and spatial extent of the auroral precipitation and the ionospheric currents associated with the surge. The electron precipitation region is deduced to have a latitudinal scale size of <100 km and to move poleward with a speed of approx.1--2 km/s coincident with the movement of a westward electrojet.

  13. Hilbert-Huang transform and S-transform of geomagnetic pulsations at auroral expansion onset

    NASA Astrophysics Data System (ADS)

    Kataoka, R.; Miyoshi, Y.; Morioka, A.

    2009-12-01

    The waveform of geomagnetic pulsations at auroral expansion onset looks irregular and is hardly resolved by Fourier transform. Here we perform a novel analysis of the Hilbert-Huang Transform (HHT) to address this problem, focusing on the event investigated in detail by Morioka et al. [2008], in which the AKR (auroral kilometric radiation) breakup was clearly identified. From the HHT analysis of high-latitude search-coil ground magnetometer data, Pi1, Pc3, and Pi2 pulsations are extracted as the first, second, and third intrinsic mode functions, respectively. Amplification of the Pi1 and Pc3 pulsations is first detected as a clear precursor to the AKR breakup. The Pi1 and Pc3 pulsations show sudden enhancement at the AKR breakup. We suggest that the HHT is capable of automatically extracting the Pi1, Pi2, and Pc3 from the irregular high-latitude geomagnetic pulsations, providing a new type of diagnostic tools for understanding the onset mechanism of auroral substorms. A comprehensive time-frequency spectral view is obtained from the instantaneous frequency, especially when complemented with the S-transform, and the instantaneous frequency provides a new objective criterion to identify the type of geomagnetic pulsations such as Pi and Pc. It would be useful to apply the HHT to all the available both ground- and space-based magnetic datasets across all local times and latitudes for diagnosing the wave activities and underlying physics associated with the substorm onset.

  14. Average and worst-case specifications of precipitating auroral electron environment

    NASA Technical Reports Server (NTRS)

    Hardy, D. A.; Burke, W. J.; Gussenhoven, M. S.; Holeman, E.; Yeh, H. C.

    1985-01-01

    The precipitation electrons in the auroral environment are highly variable in their energy and intensity in both space and time. As such they are a source of potential hazard to the operation of the Space Shuttle and other large spacecraft operating in polar orbit. In order to assess these hazards both the average and extreme states of the precipitating electrons must be determined. Work aimed at such a specification is presented. First results of a global study of the average characteristics are presented. In this study the high latitude region was divided into spatial elements in magnetic local time and corrected geomagnetic latitude. The average electron spectrum was then determined in each spatial element for seven different levels of activity as measured by K sub p using an extremely large data set of auroral observations. Second a case study of an extreme auroral electron environment is presented, in which the electrons are accelerated through field aligned potential as high as 30,000 volts and in which the spacecraft is seen to charge negatively to a potential approaching .5 kilovolts.

  15. Effects of substorm electrojet on declination along concurrent geomagnetic latitudes in the northern auroral zone

    NASA Astrophysics Data System (ADS)

    Edvardsen, Inge; Johnsen, Magnar G.; Løvhaug, Unni P.

    2016-10-01

    The geomagnetic field often experiences large fluctuations, especially at high latitudes in the auroral zones. We have found, using simulations, that there are significant differences in the substorm signature, in certain coordinate systems, as a function of longitude. This is confirmed by the analysis of real, measured data from comparable locations. Large geomagnetic fluctuations pose challenges for companies involved in resource exploitation since the Earth's magnetic field is used as the reference when navigating drilling equipment. It is widely known that geomagnetic activity increases with increasing latitude and that the largest fluctuations are caused by substorms. In the auroral zones, substorms are common phenomena, occurring almost every night. In principle, the magnitude of geomagnetic disturbances from two identical substorms along concurrent geomagnetic latitudes around the globe, at different local times, will be the same. However, the signature of a substorm will change as a function of geomagnetic longitude due to varying declination, dipole declination, and horizontal magnetic field along constant geomagnetic latitudes. To investigate and quantify this, we applied a simple substorm current wedge model in combination with a dipole representation of the Earth's magnetic field to simulate magnetic substorms of different morphologies and local times. The results of these simulations were compared to statistical data from observatories and are discussed in the context of resource exploitation in the Arctic. We also attempt to determine and quantify areas in the auroral zone where there is a potential for increased space weather challenges compared to other areas.

  16. ESA's Cluster solved an auroral puzzle

    NASA Astrophysics Data System (ADS)

    2003-05-01

    These aurorae - seen as bright spots in Earth’s atmosphere and called ‘dayside proton auroral spots’ - occur when fractures appear in the Earth’s magnetic field, allowing particles given out from the Sun to squirt through and collide with the molecules in our atmosphere. This is the first time that a precise and direct connection between the two events has been made. The Earth’s magnetic field acts like a shield, protecting Earth from the constant stream of tiny particles ejected by the Sun and known as the ‘solar wind’. The solar wind itself is made of hydrogen atoms, broken into their constituent pieces: protons and electrons. When electrons find routes into our atmosphere, they collide with and excite the atoms in the air. When these excited atoms release their energy, it is given out as light, creating the glowing ‘curtains’ we see as the aurora borealis (or the aurora australis in the southern hemisphere). Dayside proton auroral spots are caused by protons ‘stealing’ electrons from the atoms in our atmosphere. On 18 March last year, a jet of energetic solar protons collided with the Earth’s atmosphere and created a bright ‘spot’ seen by NASA’s IMAGE spacecraft, just as Cluster passed overhead and straight through the region where the proton jet was emanating. An extensive analysis of the Cluster results has now shown that the region was experiencing a turbulent event known as ‘magnetic reconnection’. Such a phenomenon takes place when the Earth’s usually impenetrable magnetic field fractures and has to find a new stable configuration. Until the field mends itself, solar protons leak through the gap and jet into Earth’s atmosphere creating the dayside proton aurora. Philippe Escoubet, ESA’s Cluster Project Scientist, comments, “Thanks to Cluster’s observations scientists can directly and firmly link for the first time a dayside proton auroral spot and a magnetic reconnection event.” Tai Phan, leading the

  17. Polar/Tide Observations of Field Aligned O(+) Flows at 5000 km Altitude over the Auroral Regions in Comparison to UVI Auroral Images

    NASA Technical Reports Server (NTRS)

    Stevenson, Benjamin Adam; Craven, Paul D.; Chandler, Michael O.; Moore, Thomas E.; Giles, Barbara L.; Parks, G. K.; Pollock, Craig J.

    1999-01-01

    Measurements of thermal O(+) ion parameters from the Thermal Ion Dynamics Experiment (TIDE) on POLAR obtained near 5000 km altitude are compared with auroral images from the Ultra Violet Imager (UVI), for southern perigee passes. Ion parameters, including parallel velocity, density, and flux are combined with simultaneous auroral images to investigate relationships between their properties and the structure and brightness of the auroral forms. Results indicate field aligned upflowing O(+) ions over bright auroral regions and downward flows over dark regions. These and other relationships will be presented for several POLAR passes when both ion measurements and auroral images are observed under favorable conditions for comparison.

  18. MITHRAS studies of the auroral oval and polar cap

    NASA Astrophysics Data System (ADS)

    Delabeaujardiere, Odile; Watermann, Juergen; Johnson, Robert M.

    1991-01-01

    MITHRAS is a program of coordinated experiments dedicated to studying the coupling between the magnetosphere, the ionosphere, and the thermosphere. MITHRAS observations mostly involve the Sondrestrom radar in Greenland, but other incoherent scatter radars around the world were also used. Contract highlights include the following items. (1) The most extensive comparisons ever made between incoherent scatter radar data and numerical simulation models were performed. These comparisons were based on both individual case studies and averaged data, and included observations from all the incoherent scatter radars. The comparisons showed general agreement between observations and model calculations but they also showed significant differences. (2) During solar maximum conditions, the contribution to the height integrated Pederson conductivity from solar produced F-region ionization can be as large as 60 pct. of the total. (3) Under certain geophysical conditions it appears possible to identify the low altitude cusp and distinguish it from the cleft. The cusp proper appears to be characterized by enhanced F region plasma density collocated with elevated F region electron temperature; it does not appear to be associated with a particular plasma flow pattern signature. (4) A new mechanism was proposed to explain how auroral surges might be formed. It was suggested that the surge was associated with a distortion of the poleward boundary of the aurora, and that this distortion was caused by the field aligned current.

  19. A rocket-borne investigation of auroral electrodynamics within the auroral-ionosphere

    NASA Astrophysics Data System (ADS)

    Kaeppler, Stephen Roland

    This dissertation focuses on data analyzed from the Auroral Current and Electrodynamics Structure (ACES) sounding rocket mission. ACES consisted of two payloads launched nearly simultaneously in 2009 into a dynamic multiple-arc aurora. The mission was designed to observe the three-dimensional current system of an auroral arc system. To constrain the spatial-temporal ambiguity, the payloads were flown along nearly conjugate magnetic field footpoints, at various altitudes with small temporal separation. The high altitude payload took in situ measurements of the plasma parameters above the current closure region to measure the input signature into the lower ionosphere. The low-altitude payload took similar observations within the current closure region, where perpendicular cross-field currents can flow. A detailed description of the experimental configuration is presented, including operational details of the fields and plasma instruments flown on both payloads. The methods used to process data from the electrostatic particle detectors and the fluxgate magnetometer on both payloads are presented. Data from the all-sky imager details the auroral configuration at the time of launch. In situ data are presented detailing observations of the electric fields, magnetic fields, and the electron differential energy flux, as the payloads crossed nearly conjugate magnetic field lines. Field-aligned currents were calculated from magnetometer observations on the high altitude payload. These data were combined with electron flux data to show that the high altitude payload traversed regions of upward and downward field-aligned current. The low altitude payload observed signatures in the residual magnetic field components consistent with perpendicular closure current. Ionospheric collisionality is investigated to determine if it is a significant mechanism to explain observed differences in the low energy electron flux between the high altitude and low altitude payload. As a result of

  20. DEMETER observations of bursty MF emissions and their relation to ground-level auroral MF burst

    NASA Astrophysics Data System (ADS)

    Broughton, M. C.; LaBelle, J.; Parrot, M.

    2014-12-01

    A survey of medium frequency (MF) electric field data from selected orbits of the Detection of Electro-Magnetic Emissions Transmitted from Earthquakes (DEMETER) spacecraft reveals 68 examples of a new type of bursty MF emissions occurring at high latitudes associated with auroral phenomena. These resemble auroral MF burst, a natural radio emission observed at ground level near local substorm onsets. Similar to MF burst, the bursty MF waves observed by DEMETER have broadband, impulsive frequency structure covering 1.5-3.0 MHz, amplitudes of 50-100 μV/m, an overall occurrence rate of ˜0.76% with higher occurrence during active times, and strong correlation with auroral hiss. The magnetic local time distribution of the MF waves observed by DEMETER shows peak occurrence rate near 18 MLT, somewhat earlier than the equivalent peak in the occurrence rate of ground level MF burst, though propagation effects and differences in the latitudes sampled by the two techniques may explain this discrepancy. Analysis of solar wind and SuperMAG data suggests that while the bursty MF waves observed by DEMETER are associated with enhanced auroral activity, their coincidence with substorm onset may not be as exact as that of ground level MF burst. One conjunction occurs in which MF burst is observed at Churchill, Manitoba, within 8 min of MF emissions detected by DEMETER on field lines approximately 1000 km southeast of Churchill. These observations may plausibly be associated with the same auroral event detected by ground level magnetometers at several Canadian observatories. Although it is uncertain, the balance of the evidence suggests that the bursty MF waves observed with DEMETER are the same phenomenon as the ground level MF burst. Hence, theories of MF burst generation in the ionosphere, such as beam-generated Langmuir waves excited over a range of altitudes or strong Langmuir turbulence generating a range of frequencies within a narrow altitude range, need to be revisited to

  1. Influence of auroral streamers on rapid evolution of SAPS flows

    NASA Astrophysics Data System (ADS)

    Gallardo-Lacourt, B.; Nishimura, T.; Lyons, L. R.; Ruohoniemi, J. M.; Donovan, E.; Angelopoulos, V.; Nishitani, N.

    2015-12-01

    An important manifestation of plasma transport in the ionosphere is Subauroral Polarization Streams or SAPS, which are strong westward flow lying just equatorward of the electron auroral oval and thus of enhanced ionospheric conductivities of the auroral oval. While SAPS are known to intensify due to substorm injections, recent studies showed that large variability of SAPS flow can occur well after substorm onset and even during non-substorm times. These SAPS enhancements have been suggested to occur in association with auroral streamers that propagate equatorward, a suggestion that would indicate that plasma sheet fast flows propagate into the inner magnetosphere and increase subauroral flows. We present auroral images from the THEMIS ground-based all-sky-imager array and 2-d line-of-sight flow observations from the SuperDARN radars that share fields of view with the imagers to investigate systematically the association between SAPS and auroral streamers. We surveyed events from December 2007 to April 2013 for which high or mid-latitude SuperDARN radars were available to measure the SAPS flows, and identified 60 events. For streamers observed near the equatorward boundary of the auroral oval, we find westward flow enhancements of ~200 m/s slightly equatorward of the streamers. A preliminary survey suggests that >90% of the streamers that reach close to the equatorward boundary lead to westward flow enhancements. We also characterize the SAPS flow channel width and timing relative to streamers reaching radar echo meridians. The strong influence of auroral streamers on rapid SAPS flow evolution suggests that transient fast earthward plasma sheet flows can lead to westward SAPS flow enhancements in the subauroral region, and that such enhancements are far more common than only during substorms because of the frequent occurrences of streamers under various geomagnetic conditions.

  2. Spectacular ionospheric flow structures associated with substorm auroral onset

    NASA Astrophysics Data System (ADS)

    Gallardo-Lacourt, B. I.; Nishimura, Y.; Lyons, L. R.; Zou, Y.; Angelopoulos, V.; Donovan, E.; Mende, S. B.; Ruohoniemi, J.; McWilliams, K. A.; Nishitani, N.

    2013-12-01

    Auroral observations have shown that brightening at substorm auroral onset consists of azimuthally propagating beads forming along a pre-existing arc. However, the ionospheric flow structure related to this wavy auroral structure has not been previously identified. We present 2-d line-of-sight flow observations and auroral images from the SuperDARN radars and the THEMIS ground-based all-sky-imager array to investigate the ionospheric flow pattern associated with the onset. We have selected events where SuperDARN was operating in the THEMIS mode, which provides measurements along the northward looking radar beam that have time resolution (6 s) comparable to the high time resolution of the imagers and gives us a unique tool to detect properties of flows associated with the substorm onset instability. We find very fast flows (~1000 m/s) that initiated simultaneously with the onset arc beads propagating across the THEMIS-mode beam meridian. The flows show oscillations at ~9 mHz, which corresponds to the periodicity of the auroral beads propagating across the radar beam. 2-d radar measurements also show a wavy pattern in the azimuthal direction with a wavelength of ~74 km, which is close to the azimuthal separation of individual beads, although this determination is limited by the 2 minute radar scan period. These strong correlations (in time and space) between auroral beading and the fast ionospheric flows suggest that these spectacular flows are an important feature of the substorm onset instability within the inner plasma sheet. Also, a clockwise flow shear was observed in association with individual auroral beads, suggesting that such flow shear is a feature of the unstable substorm onset waves.

  3. Playing by Programming: Making Gameplay a Programming Activity

    ERIC Educational Resources Information Center

    Weintrop, David; Wilensky, Uri

    2016-01-01

    Video games are an oft-cited reason for young learners getting interested in programming and computer science. As such, many learning opportunities build on this interest by having kids program their own video games. This approach, while sometimes successful, has its drawbacks stemming from the fact that the challenge of programming and game…

  4. Localized Ionospheric Particle Acceleration and Wave Acceleration of Auroral Ions: Amicist Data Set

    NASA Technical Reports Server (NTRS)

    Lynch, Kristina A.

    1999-01-01

    Research supported by this grant covered two main topics: auroral ion acceleration from ELF-band wave activity, and from VLF-spikelet (lower hybrid solitary structure) wave activity. Recent auroral sounding rocket data illustrate the relative significance of various mechanisms for initiating auroral ion outflow. Two nightside mechanisms are shown in detail. The first mechanism is ion acceleration within lower hybrid solitary wave events. The new data from this two payload mission show clearly that: (1) these individual events are spatially localized to scales approximately 100 m wide perpendicular to B, in agreement with previous investigations of these structures, and (2) that the probability of occurrence of the events is greatest at times of maximum VLF wave intensity. The second mechanism is ion acceleration by broadband, low frequency electrostatic waves, observed in a 30 km wide region at the poleward edge of the arc. The ion fluxes from the two mechanisms are compared and it is shown that while lower hybrid solitary structures do indeed accelerate ions in regions of intense VLF waves, the outflow from the electrostatic ion wave acceleration region is dominant for the aurora investigated by this sounding rocket, AMICIST. The fluxes are shown to be consistent with DE-1 and Freja outflow measurements, indicating that the AMICIST observations show the low altitude, microphysical signatures of nightside auroral outflow. In this paper, we present a review of sounding rocket observations of the ion acceleration seen nightside auroral zone lower hybrid solitary structures. Observations from Topaz3, Amicist, and Phaze2 are presented on various spatial scales, including the two-point measurements of the Amicist mission. From this collection of observations, we will demonstrate the following characteristics of transverse ion acceleration (TAI) in LHSS. The ion acceleration process is narrowly confined to 90 degrees pitch angle, in spatially confined regions of up to a

  5. Dynamics of a discrete auroral arc

    NASA Astrophysics Data System (ADS)

    Bruening, K.; Goertz, C. K.

    1986-06-01

    Porcupine Flight 4 data were used to determine the field-aligned currents associated with a southward moving discrete auroral arc in the postmidnight sector. Three different methods were used for determining the field-aligned current which should give identical results if the arcs are quasi-stationary and no parallel electric field exists between the payload and the dynamo region of the ionosphere. As long as the rocket is above the arc, the three methods agree. The integral of precipitating electron flux, the local magnetic field perturbations, and the divergence of the horizontal Pedersen current all indicate an upward current of 5 + or - 3 microamperes/sq m. Immediately north of the arc a strong downward current of about 10-20 microamperes/sq m is detected. The magnitude, however, is not well known because the rocket's velocity relative to the arc cannot be clearly established. Further north of the southward moving arc, the two methods that can be applied (magnetic field perturbations and divergence of the horizontal Pedersen current) yield contradictory results not only about the magnitude of the current but also about the direction of the current. It is suggested that this discrepancy is due to time-dependent electric field.

  6. Dynamics of a discrete auroral arc

    NASA Technical Reports Server (NTRS)

    Bruening, K.; Goertz, C. K.

    1986-01-01

    Porcupine Flight 4 data were used to determine the field-aligned currents associated with a southward moving discrete auroral arc in the postmidnight sector. Three different methods were used for determining the field-aligned current which should give identical results if the arcs are quasi-stationary and no parallel electric field exists between the payload and the dynamo region of the ionosphere. As long as the rocket is above the arc, the three methods agree. The integral of precipitating electron flux, the local magnetic field perturbations, and the divergence of the horizontal Pedersen current all indicate an upward current of 5 + or - 3 microamperes/sq m. Immediately north of the arc a strong downward current of about 10-20 microamperes/sq m is detected. The magnitude, however, is not well known because the rocket's velocity relative to the arc cannot be clearly established. Further north of the southward moving arc, the two methods that can be applied (magnetic field perturbations and divergence of the horizontal Pedersen current) yield contradictory results not only about the magnitude of the current but also about the direction of the current. It is suggested that this discrepancy is due to time-dependent electric field.

  7. 28 CFR 54.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 54.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  8. 28 CFR 54.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 54.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  9. 45 CFR 86.31 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 86.31 Education programs or activities. (a) General. Except as provided elsewhere in this part, no person shall, on the basis of sex,...

  10. 14 CFR 1253.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 5 2013-01-01 2013-01-01 false Education programs or activities. 1253.400... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1253.400 Education...

  11. 14 CFR § 1253.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Education programs or activities. § 1253... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1253.400 Education...

  12. 14 CFR 1253.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Education programs or activities. 1253.400... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1253.400 Education...

  13. 13 CFR 113.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Education programs or activities... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Education Programs Or Activities Prohibited §...

  14. 13 CFR 113.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 13 Business Credit and Assistance 1 2014-01-01 2014-01-01 false Education programs or activities... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Education Programs Or Activities Prohibited §...

  15. 28 CFR 54.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 54.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  16. 45 CFR 86.31 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 86.31 Education programs or activities. (a) General. Except as provided elsewhere in this part, no person shall, on the basis of sex,...

  17. 22 CFR 229.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 229.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  18. 45 CFR 86.31 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 86.31 Education programs or activities. (a) General. Except as provided elsewhere in this part, no person shall, on the basis of sex,...

  19. 13 CFR 113.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Education programs or activities... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Education Programs Or Activities Prohibited §...

  20. Properties of the Auroral Zone Ionosphere Inferred Using Plasma Contactor Data From the International Space Station

    NASA Astrophysics Data System (ADS)

    Koontz, S. L.; Bering, E. A.; Evans, D. S.; Katz, I.; Gardner, B. M.; Suggs, R. M.; Minow, J. I.; Dalton, P. J.; Ferguson, D. C.; Hillard, G. B.; Counts, J. L.; Barsamian, H.; Kern, J.; Mikatarian, R.

    2001-12-01

    observations order themselves with geomagnetic activity. We will compare the peak densities with auroral energy inputs inferred from electron precipitation monitors on the NOAA-15 and NOAA-16 spacecraft.

  1. Auroral signatures of Bursty Bulk Flows from magnetosphere-ionosphere coupling models

    NASA Astrophysics Data System (ADS)

    Echim, M.; de Keyser, J. M.; Roth, M. A.

    2010-12-01

    The relationship between bursty bulk flows (BBFs) in the magnetospheric tail and the activation of auroral forms is well established from satellite and ground-based observations. Starting from a self-consistent description of BBFs based on a Vlasov equilibrium we provide a quantitative evaluation of the associated auroral effects by using a quasi-stationary magnetosphere-ionosphere (MI) coupling model. The self-consistent BBF model is based on a kinetic description of a 1-D plasma slab moving in background plasma and electromagnetic field. The model considers two exact constants of motion and one adiabatic invariant (the magnetic moment). It solves the coupled Vlasov-Maxwell system of equations in one spatial dimension (perpendicular to the BBFs plasma bulk velocity and the main magnetic field) assuming the BBF is a 1D structure elongated in the direction of the background magnetic field. The BBF model provides the self-consistent profile of Φm, the electric potential, showing the formation of convergent electric fields at the dawnward flank of the Earth-ward oriented BBFs. It has been shown that magnetospheric convergent electric fields drive field-aligned (FA) potential drops, FA currents and electron precipitation and acceleration. A stationary MI coupling model developed for discontinuity-like magnetospheric generators with convergent electric fields developed earlier is adapted to describe the coupling between the BBFs and the auroral ionosphere. The kernel of the MI coupling model is the condition of current continuity at the topside ionosphere, from which we compute the electric potential in the ionosphere for a given Φm. The MI coupling model is based on a Knight-type current-voltage relationship and a height-integrated conductivity model that depends on the energy deposited in the ionosphere by precipitating electrons. We show that the convergent electric field formed at the flanks of the BBF drive a FA potential drop and downward electron acceleration

  2. New Observational Constraints on Theories of Auroral Arc Generation

    NASA Astrophysics Data System (ADS)

    McGuffin, N.; Donovan, E.; Spanswick, E.; Knudsen, D. J.; Rankin, R.; Baker, G.; Uritsky, V. M.; Jackel, B. J.; Barnetson, K.

    2009-12-01

    We do not know how auroral arcs are formed, whether or not there are different types of arcs (meaning different underlying physics), nor what arcs correspond to in the magnetosphere. Given the ubiquity of arcs and their obvious importance to MI coupling, including specific processes such as the substorm, resolving the questions we have about arcs is one of the key objectives in space physics. We have carried out a survey of a two-year subset of the THEMIS ASI image data set. In this survey, we have classified the ~150M images in terms of viewing conditions, presence or absence of aurora, and auroral type. One of the consequences of this survey is that we have amassed what is arguably (to date) the largest set of images of auroral arcs. This set of arcs spans all auroral latitudes and magnetic local times except for a few hours around local noon. In this paper we use this auroral survey, together with the results of a similar survey of the proton aurora (from the NORSTAR Meridian Scanning Photometer array) and magnetic pulsations (published by Baker et al. [JGR, Volume 108, doi:10.1029/2002JA009801, 2003]), to elucidate some new quantitative and qualitative results including the following: 1) auroral arcs occur on field lines that are poleward of the ion isotropy boundary; 2) the orientation of arcs in geomagnetic coordinates suggest that arcs are an ionospheric projection of a gradient of some as yet unidentified magnetospheric parameter; 3) although some arcs oscillate in ways that are compellingly suggestive of their generation via field line resonances, most auroral arcs do not oscillate; 4) the magnetic local time where auroral arc occurrence peaks corresponds to a minimum in the occurrence of Pc5 pulsations and field line resonances. We will conclude with a discussion of the implications of these results for models of auroral arc generation. MLT occurrence distributions of arcs (gray histogram) and FLRs in the Pc5 spectral band (transparent histogram with dark

  3. Juno's Earth flyby: the Jovian infrared Auroral Mapper preliminary results

    NASA Astrophysics Data System (ADS)

    Adriani, A.; Moriconi, M. L.; Mura, A.; Tosi, F.; Sindoni, G.; Noschese, R.; Cicchetti, A.; Filacchione, G.

    2016-08-01

    The Jovian InfraRed Auroral Mapper, JIRAM, is an image-spectrometer onboard the NASA Juno spacecraft flying to Jupiter. The instrument has been designed to study the aurora and the atmosphere of the planet in the spectral range 2-5 μm. The very first scientific observation taken with the instrument was at the Moon just before Juno's Earth fly-by occurred on October 9, 2013. The purpose was to check the instrument regular operation modes and to optimize the instrumental performances. The testing activity will be completed with pointing and a radiometric/spectral calibrations shortly after Jupiter Orbit Insertion. Then the reconstruction of some Moon infrared images, together with co-located spectra used to retrieve the lunar surface temperature, is a fundamental step in the instrument operation tuning. The main scope of this article is to serve as a reference to future users of the JIRAM datasets after public release with the NASA Planetary Data System.

  4. Observations of field line resonance with global auroral images

    NASA Astrophysics Data System (ADS)

    Liou, K.; Takahashi, K.

    2013-12-01

    We report results from a detailed analysis of an auroral luminosity pulsation event in the Pc 5 range associated with auroral breakup using Polar ultraviolet imager data and magnetic field observations from the ground-based CARISMA magnetometer array and in space by the GOES 8 satellite. It is found that (1) the auroral pulsation appeared predominantly at frequencies around ~0.9 mHz and ~1.8 mHz in the midnight sector centered at the onset (~2100 magnetic local time (MLT)), (2) the longitudinal extent of the auroral pulsation is wider (~12 h in MLT) for the lower-frequency mode and is much narrower for the higher-frequency mode (~3 h in MLT), (3) both auroral and ground magnetic field data show latitudinal wave amplitude and phase shift structures consistent with the field-line resonance (FLR) theory, (4) magnetic field measurements from GOES 8, which was near the onset location, also show two spectral peaks at ~0.9 mHz in the compressional component and at ~2.1 mHz in the poloidal component. It is suggested the observed Pc 5 ULF waves are FLRs produced by the onset-associated magnetic field dipolarization.

  5. Analytic model of aurorally coupled magnetospheric and ionospheric electrostatic potentials

    NASA Technical Reports Server (NTRS)

    Cornwall, J. M.

    1994-01-01

    This paper describes modest but significant improvements on earlier studies of electrostatic potential structure in the auroral region using the adiabatic auroral arc model. This model has crucial nonlinearities (connected, for example. with aurorally produced ionization) which have hampered analysis; earlier work has either been linear, which I will show is a poor approximation or, if nonlinear, either numerical or too specialized to study parametric dependencies. With certain simplifying assumptions I find new analytic nonlinear solutions fully exhibiting the parametric dependence of potentials on magnetospheric (e.g.. cross-tail potential) and ionospheric (e.g., recombination rate) parameters. No purely phenomenological parameters are introduced. The results are in reasonable agreement with observed average auroral potential drops, inverted-V scale sizes, and dissipation rates. The dissipation rate is quite comparable to tail energization and transport rates and should have a major effect on tail and magnetospheric dynamics. This paper gives various relations between the cross-tail potential and auroral parameters (e.g., total parallel currents and potential drops) which can be studied with existing data sets.

  6. Space Weather Monitoring for ISS Space Environments Engineering and Crew Auroral Observations

    NASA Technical Reports Server (NTRS)

    Minow, Joseph; Pettit, Donald R.; Hartman, William A.

    2012-01-01

    Today s presentation describes how real time space weather data is used by the International Space Station (ISS) space environments team to obtain data on auroral charging of the ISS vehicle and support ISS crew efforts to obtain auroral images from orbit. Topics covered include: Floating Potential Measurement Unit (FPMU), . Auroral charging of ISS, . Real ]time space weather monitoring resources, . Examples of ISS auroral charging captured from space weather events, . ISS crew observations of aurora.

  7. Nonproliferation and counterproliferation activities and programs

    SciTech Connect

    1994-05-01

    At least twenty countries-many of them hostile to the United States and its allies-have now or are seeking to develop the capability to produce nuclear, biological and/or chemical weapons of mass destruction and the means to deliver them. More than twelve countries have operational ballistic missiles, and others have programs to develop them. Weapons of mass destruction may directly threaten US forces in the field and, in a more perplexing way, threaten the effective force employment by requiring dispersal of those forces. Potential adversaries may use weapons of mass destruction to deter US power projection abroad. As President Clinton stated to `If we do not stem the proliferation of the world`s deadliest weapons, no democracy can feel secure.` Because of concern over this threat, the National Defense Authorization Act of 1994 (NDAA 94) required the establishment of an interagency review committee composed of representatives from the Departments of State, Defense, Energy, the Intelligence Community, the Joint Chiefs of Staff and the Arms Control Disarmament Agency and tasked the committee to report on nonproliferation and counterproliferation activities and programs. To ensure comprehensiveness, representatives of other departments and agencies were asked to participate. In accordance with NDAA 94, this report provides a top-down overview of existing, planned and proposed capabilities and technologies, as well as a description of priorities, programmatic options and other issues.

  8. Auroral boundary movement rates during substorm onsets and their correspondence to solar wind and the AL index

    NASA Astrophysics Data System (ADS)

    Andriyas, Tushar

    2016-08-01

    A statistical analysis of the equatorward and poleward auroral boundary movement during substorm onsets, the related solar wind activity, GOES 8 and 10 magnetic field, and the westward auroral electrojet (AL) index is undertaken, during the years 2000-2002. Auroral boundary data were obtained from the British Antarctic Survey (BAS). These boundaries were derived using auroral images from the IMAGE satellite. The timing of the onsets was derived from the Frey et al. (2004) database. Data were also classified based on the peak AL around the onset and the onset latitude, in order to analyze the differences, if any, in the rates of movement. It was found that the absolute ratio of the rate of movement of the mean poleward and equatorward boundaries was slower than the rate of mean movement around the midnight sector. The stronger the onset (in terms of the peak AL around the onset) was, the faster the rate of movement for both the boundaries. This implies that the stronger the AL signature around the onset, the weaker the magnetic field was prior to the onset and the faster it increased after the onset at GOES 8 and 10 locations. The stronger the AL signature, the thicker the latitudinal width of the aurora was, prior to the onset and higher was the increase in the width after the onset, due to large poleward and average equatorward expansion. Magnetotail field line stretching and relaxation rates as measured by GOES were also found to lie in the same order of magnitude. It is therefore concluded that the rates of latitudinal descent prior to a substorm onset and ascent after the onset, of the mean auroral boundaries, corresponds to the rate at which the tail field lines stretch and relax before and after the onset, respectively.

  9. The current-voltage relationship in auroral current sheets

    NASA Technical Reports Server (NTRS)

    Weimer, D. R.; Gurnett, D. A.; Goertz, C. K.; Menietti, J. D.; Burch, J. L.

    1987-01-01

    The current-voltage relation within narrow auroral current sheets is examined through the use of high-resolution data from the high altitude Dynamics Explorer 1 satellite. The north-south perpendicular electric field and the east-west magnetic field are shown for three cases in which there are large amplitude, oppositely directed paired electric fields and narrow current sheets. These data are shown to indicate that there is a linear Ohm's law relationship between the current density and the parallel potential drop within the narrow current sheets. This linear relationship had previously been verified for large-scale auroral formations greater than 20 km wide at the ionosphere. The evidence shown here extends our knowledge down to the scale size of discrete auroral arcs.

  10. ULF Waves above the Nightside Auroral Oval during Substorm Onset

    NASA Astrophysics Data System (ADS)

    Rae, I. J.; Watt, C. E. J.

    2016-02-01

    This chapter reviews historical ground-based observations of ultra-low-frequency (ULF) waves tied to substorms, and highlights new research linking these ULF waves explicitly to substorm onset itself. There are several robust methods that can be used to determine the characteristics of a nonstationary time series such as the ULF magnetic field traces observed in the auroral zone during substorms. These include the pure state filter, the Hilbert-Huang transform, and wavelet analysis. The first indication of a substorm is a sudden brightening of one of the quiet arcs lying in the midnight sector of the oval. The chapter focuses on the properties of ULF waves that are seen in two-dimensional images of auroral intensity near substorm expansion phase onset. It also discusses a wider range of magnetotail instabilities that could be responsible for the azimuthally structured auroral forms at substorm onset.

  11. Auroral oval as a beautiful but outdated paradigm

    NASA Astrophysics Data System (ADS)

    Lazutin, Leonid

    2015-03-01

    Auroral oval as an important region of the polar ionosphere presents in a considerable number of a studies of the disturbed magnetosphere. It seems that all about oval is known to all researchers. But there are evidences in a publications that misunderstanding exists and that it is a time for a review on this subject. Most of papers describing auroral position and dynamics were published years ago and became a rarity. We will tell on the history of aurora's distribution before the oval discovery, how the oval was discovered and how it changed our point of view on magnetosphere processes. We will tell also how the oval paradigm grows and haw with time it became non-productive (at our point of view) for a studies of magnetosphere structure and disturbances. Finally we will indicate the position of the aural zone and auroral magnetosphere among the main domains of the magnetosphere.

  12. Polar cap auroral electron fluxes observed with Isis 1

    NASA Technical Reports Server (NTRS)

    Winningham, J. D.; Heikkila, W. J.

    1974-01-01

    Three types of auroral particle precipitation have been observed over the polar caps, well inside the auroral oval, by means of the soft particle spectrometer on the Isis 1 satellite. The first type is a uniform, very soft (about 100 eV) electron 'polar rain' over the entire polar cap; this may well be present with very weak intensity at all times, but it is markedly enhanced during worldwide geomagnetic storms. A second type of precipitation is a structured flux of electrons with energies near 1 keV, suggestive of localized 'polar showers'; it seems likely that these are the cause of the sun-aligned auroral arcs that have been observed during moderately quiet conditions. During periods of intense magnetic disturbance this precipitation can become very intense and exhibit a characteristic pattern that we have come to call a 'polar squall'.

  13. Association of plasma sheet variations with auroral changes during substorms

    SciTech Connect

    Hones, E.W. Jr.; Craven, J.D.; Frank, L.A.; Parks, G.K.

    1988-01-01

    Images of the southern auroral oval taken by the University of Iowa auroral imaging instrumentation on the Dynamics Explorer 1 satellite during an isolated substorm are correlated with plasma measurements made concurrently by the ISEE 1 satellite in the magnetotail. Qualitative magnetic field configuration changes necessary to relate the plasma sheet boundary location to the latitude of the auroras are discussed. Evidence is presented that the longitudinal advances of the auroras after expansive phase onset are mappings of a neutral line lengthening across the near-tail. We observe a rapid poleward auroral surge, occurring about 1 hour after expansive phase onset, to coincide with the peak of the AL index and argue that the total set of observations at that time is consistent with the picture of a /open quotes/poleward leap/close quotes/ of the electrojet marking the beginning of the substorm's recovery. 9 refs. 3 figs.

  14. Program activities, DOE state and local assistance programs, 1980 report

    SciTech Connect

    Chiogioji, Melvin H.

    1981-01-01

    Progress achieved by DOE State and Local Assistance Programs during FY 1980 and since they were established is summarized. These programs enable improved energy efficiency of industry, transportation, commercial establishments, public buildings, and residences. Eight programs (State Energy Conservation, Energy Extension Service, Weatherization Assistance, Institutional Buildings Grants, Energy-Related Inventions, Appropriate Technology Small Grants, Emergency Energy Conservation, Emergency Building Temperature Restrictions) are described. They provide the impetus for thousands of individual and organizational actions that have significantly affected national energy use patterns. (MCW)

  15. Program activities: DOE State and Local Assistance Programs, 1983 report

    SciTech Connect

    Not Available

    1983-10-01

    Progress achieved by the Department of Energy State and Local Assistance programs during FY 1983 and prior years is summarized. These programs provide financial and technical assistance to and through state and local governments, enabling them to plan and implement measures to improve the energy efficiency of industry, transportation, commercial establishments, public buildings and residences. The programs covered here are: State Energy Conservation, Energy Extension Service, Weatherization Assistance, Institutional Conservation, Energy-Related Inventions, Appropriate Technology Small Grants, and Grants Management and Technical Assistance. (MHR)

  16. Backward wave cyclotron-maser emission in the auroral magnetosphere.

    PubMed

    Speirs, D C; Bingham, R; Cairns, R A; Vorgul, I; Kellett, B J; Phelps, A D R; Ronald, K

    2014-10-10

    In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's auroral region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity. We also show that the radiation is preferentially amplified along the auroral oval rather than transversely. The results are in agreement with recent Cluster observations. PMID:25375713

  17. Backward wave cyclotron-maser emission in the auroral magnetosphere.

    PubMed

    Speirs, D C; Bingham, R; Cairns, R A; Vorgul, I; Kellett, B J; Phelps, A D R; Ronald, K

    2014-10-10

    In this Letter, we present theory and particle-in-cell simulations describing cyclotron radio emission from Earth's auroral region and similar phenomena in other astrophysical environments. In particular, we find that the radiation, generated by a down-going electron horseshoe distribution is due to a backward-wave cyclotron-maser emission process. The backward wave nature of the radiation contributes to upward refraction of the radiation that is also enhanced by a density inhomogeneity. We also show that the radiation is preferentially amplified along the auroral oval rather than transversely. The results are in agreement with recent Cluster observations.

  18. Upper hybrid and Langmuir turbulence in the auroral E region

    NASA Technical Reports Server (NTRS)

    Kelley, Michael C.; Earle, Gregory D.

    1988-01-01

    Oscillations at a frequency between the local upper hybrid and plasma frequencies have been detected in the upper E region of the morning auroral oval. The emission occurs in a narrow band of frequencies when the dipole antenna is nearly perpendicular to B but broadens when the antenna has a component parallel to B. The waves have a low-altitude cutoff at about 125-130 km, and their intensity increases in regions of low plasma density. No theoretical explanation yet exists for these waves, which may be the manifestation of a plasma instability process due to the suprathermal electron flux which accompanies collisional ionization in the auroral E region.

  19. Identifying and understanding Indigenous ways of evaluating physical activity programs.

    PubMed

    Roberts, Erica Blue; Butler Iii, James; Green, Kerry M; Chaudhary, Kaushal Raj

    2016-01-01

    Indigenous evaluation frameworks have not been investigated in the context of American Indian and Alaska Native (AI/AN) physical activity programs, an important area given the relationship between effective physical activity programs and quality of life among these populations. To address this gap, staff members of AI/AN physical activity programs were interviewed to explore their understanding of and experiences with evaluation. Findings suggest that Indigenous evaluation is perceived as narrative and holistic, Indigenous knowledge is used in program decision making, though it is not always acknowledged as evaluation, and there is not a universally desired way to evaluate AI/AN physical activity programs. PMID:27668593

  20. 45 CFR 618.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 618.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  1. 14 CFR 1253.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1253.400 Education programs... shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or...

  2. A summary of the active flexible wing program

    NASA Technical Reports Server (NTRS)

    Perry, Boyd, III; Cole, Stanley R.; Miller, Gerald D.

    1992-01-01

    A summary of the NASA/Rockwell Active Flexible Wing Program is presented. Major elements of the program are presented. Key program accomplishments included single- and multiple-mode flutter suppression, load alleviation and load control during rapid roll maneuvers, and multi-input/multi-output multiple-function active controls tests above the open-loop flutter boundary.

  3. 10 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Education programs or activities. 5.400 Section 5.400 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  4. 7 CFR 15a.31 - Education programs and activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Education programs and activities. 15a.31 Section 15a.31 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  5. 10 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Education programs or activities. 5.400 Section 5.400 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  6. 38 CFR 23.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2014-07-01 2014-07-01 false Education programs or... (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited §...

  7. 45 CFR 2555.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 4 2014-10-01 2014-10-01 false Education programs or activities. 2555.400 Section... COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  8. 45 CFR 2555.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 4 2012-10-01 2012-10-01 false Education programs or activities. 2555.400 Section... COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  9. 24 CFR 3.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Education programs or activities. 3... Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  10. 18 CFR 1317.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Education programs or... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1317.400 Education...

  11. 7 CFR 15a.31 - Education programs and activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Education programs and activities. 15a.31 Section 15a.31 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  12. 18 CFR 1317.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Education programs or... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1317.400 Education...

  13. 18 CFR 1317.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Education programs or... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1317.400 Education...

  14. 32 CFR 196.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Education programs or activities. 196.400... (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  15. 32 CFR 196.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Education programs or activities. 196.400... (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  16. 45 CFR 2555.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 4 2013-10-01 2013-10-01 false Education programs or activities. 2555.400 Section... COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  17. 38 CFR 23.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2013-07-01 2013-07-01 false Education programs or... (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited §...

  18. 10 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Education programs or activities. 5.400 Section 5.400 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  19. 29 CFR 36.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false Education programs or activities. 36.400 Section 36.400 Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  20. 38 CFR 23.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2012-07-01 2012-07-01 false Education programs or... (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited §...

  1. 32 CFR 196.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Education programs or activities. 196.400... (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  2. 24 CFR 3.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Education programs or activities. 3... Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  3. 7 CFR 15a.31 - Education programs and activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Education programs and activities. 15a.31 Section 15a.31 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  4. 24 CFR 3.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Education programs or activities. 3... Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  5. 40 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 5.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  6. 31 CFR 28.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 28.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  7. 43 CFR 41.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 41.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  8. 45 CFR 618.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 618.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  9. 18 CFR 1317.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1317.400 Education programs... shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or...

  10. 6 CFR 17.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 17.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  11. 15 CFR 8a.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 8a.400 Education programs or... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  12. 14 CFR 1253.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1253.400 Education programs... shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or...

  13. 13 CFR 113.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Education Programs Or Activities Prohibited § 113... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Education programs or...

  14. Exploring Extension Involvement in Farm to School Program Activities

    ERIC Educational Resources Information Center

    Benson, Matthew C.

    2014-01-01

    The study reported here examined Extension professionals' involvement in farm-to-school program activities. Results of an online survey distributed to eight state Extension systems indicate that on average, Extension professionals are involved with one farm to school program activity, with most supporting school or community garden programs.…

  15. 45 CFR 2555.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Education programs or activities. 2555.400 Section... COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  16. 29 CFR 36.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Education programs or activities. 36.400 Section 36.400 Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  17. 24 CFR 3.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Education programs or activities. 3... Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  18. 32 CFR 196.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 2 2010-07-01 2010-07-01 false Education programs or activities. 196.400... (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  19. 18 CFR 1317.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Education programs or... NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 1317.400 Education...

  20. 38 CFR 23.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Education programs or... (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited §...

  1. 7 CFR 15a.31 - Education programs and activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Education programs and activities. 15a.31 Section 15a.31 Agriculture Office of the Secretary of Agriculture EDUCATION PROGRAMS OR ACTIVITIES RECEIVING OR BENEFITTING FROM FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  2. 10 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Education programs or activities. 5.400 Section 5.400 Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  3. Fine Scale Structure observed in the Total Electron Content above the Sub-Auroral, Auroral, and Polar Ionosphere

    NASA Astrophysics Data System (ADS)

    Coster, A. J.; Thomas, E. G.; Vierinen, J.; Rideout, W. E.

    2015-12-01

    This paper details recent improvements in TEC observations made in the sub-auroral, auroral, and polar regions. The goal is high-resolution measurements of both medium and fine-scale TEC-gradients. To achieve this, the number of GNSS receivers processed was more than doubled, due to agreements made with multiple government and commercial agencies, such as those involved with highway transportation and precision farming. Following the increase in GNSS observations, additional improvements were made in the MIT Haystack GNSS data processing algorithms, allowing for finer grid spacing of the output TEC data. Merging data sets also increased sensitivity. Scintillation data from several GNSS receivers have been overlaid on top of all-sky camera images showing evidence of aurora. These data sets have been merged with the measured background TEC to monitor the development both medium and fine-scale TEC gradients. Data from multiple geomagnetic storms and auroral events in this solar cycle will be presented.

  4. Search for auroral belt E-parallel fields with high-velocity barium ion injections

    NASA Technical Reports Server (NTRS)

    Heppner, J. P.; Ledley, B. G.; Miller, M. L.; Marionni, P. A.; Pongratz, M. B.

    1989-01-01

    In April 1984, four high-velocity shaped-charge Ba(+) injections were conducted from two sounding rockets at 770-975 km over northern Alaska under conditions of active auroral and magnetic disturbance. Spatial ionization (brightness) profiles of high-velocity Ba(+) clouds from photometric scans following each release were found to be consistent with the 28-sec theoretical time constant for Ba photoionization determined by Carlsten (1975). These observations therefore revealed no evidence of anomalous fast ionization predicted by the Alfven critical velocity hypothesis.

  5. Spatial Relationships of Auroral Particle Acceleration Relative to High Latitude Plasma Boundaries

    NASA Technical Reports Server (NTRS)

    Ghielmetti, Arthur G.

    1997-01-01

    This final report describes the activities under NASA contract to Lockheed Missiles and Space Company. It covers the period from 10-1-94 to 12-31-97. The objective of this investigation is to identify and characterize the spatial relationships of auroral particle acceleration features relative to the characteristic transition features in the surrounding polar ionospheric plasmas. Due to the reduced funding level approved for this contract, the original scope of the proposed work was readjusted with the focus placed on examining spatial relationships with respect to particle structures.

  6. Status of Older Adult Physical Activity Programs in Illinois.

    ERIC Educational Resources Information Center

    Heitmann, Helen M.

    1984-01-01

    Physical fitness and recreation programs can be a deterrent to premature aging. State-funded physical activity programs for older adults in Illinois offer minimal benefits due to volunteer and untrained personnel. Results of this study are presented. (DF)

  7. Experimental tests of the generation mechanism of auroral medium frequency burst radio emissions

    NASA Astrophysics Data System (ADS)

    Bunch, N. L.; Labelle, J.; Weatherwax, A. T.; Hughes, J. M.; Lummerzheim, D.

    2009-09-01

    Medium frequency (MF) burst is an impulsive auroral radio emission at 1.3-4.5 MHz commonly detected by ground-based instruments for a few minutes at substorm onsets. It is thought to arise from mode conversion radiation. The Dartmouth College MF radio interferometer at Toolik Field Station, Alaska (68.51° invariant latitude), measured spectra, amplitudes, and directions of arrival (DOA) of 47 MF burst events during 2006-2007 and 49 events during 2007-2008. Statistical analysis of these events shows that they come predominantly from the south and east of Toolik, as expected because propagation conditions are more favorable poleward and westward of the active auroral arcs than equatorward or eastward during premidnight (westward moving) substorm onset activity. Case studies of a selected MF burst event on 20 November 2007 show that motions of the radio emissions qualitatively track the motions of auroral arcs simultaneously observed with all-sky camera. Case studies of DOA data of selected MF burst events on 31 January and 20 November 2007 show that higher-frequency components of MF burst arrive at higher elevation angles than lower-frequency components. Statistical studies confirm this trend. Ray-tracing analysis shows that this trend implies that sources of the higher-frequency components of the MF burst are at higher altitudes than those of the lower-frequency components. The analysis also shows that the MF burst comes from the bottomside F region ionosphere. These observations are consistent with a mechanism of MF burst emission whereby the emissions originate from mode conversion of Langmuir or upper hybrid waves excited over a range of altitudes in the bottomside F region.

  8. A Wide Field Auroral Imager (WFAI) for low Earth orbit missions

    NASA Astrophysics Data System (ADS)

    Bannister, N. P.; Bunce, E. J.; Cowley, S. W. H.; Fairbend, R.; Fraser, G. W.; Hamilton, F. J.; Lapington, J. S.; Lees, J. E.; Lester, M.; Milan, S. E.; Pearson, J. F.; Price, G. J.; Willingale, R.

    2007-03-01

    A comprehensive understanding of the solar wind interaction with Earth's coupled magnetosphere-ionosphere system requires an ability to observe the charged particle environment and auroral activity from the same platform, generating particle and photon image data which are matched in time and location. While unambiguous identification of the particles giving rise to the aurora requires a Low Earth Orbit satellite, obtaining adequate spatial coverage of aurorae with the relatively limited field of view of current space bourne auroral imaging systems requires much higher orbits. A goal for future satellite missions, therefore, is the development of compact, wide field-of-view optics permitting high spatial and temporal resolution ultraviolet imaging of the aurora from small spacecraft in low polar orbit. Microchannel plate optics offer a method of achieving the required performance. We describe a new, compact instrument design which can observe a wide field-of-view with the required spatial resolution. We report the focusing of 121.6 nm radiation using a spherically-slumped, square-pore microchannel plate with a focal length of 32 mm and an F number of 0.7. Measurements are compared with detailed ray-trace simulations of imaging performance. The angular resolution is 2.7±0.2° for the prototype, corresponding to a footprint ~33 km in diameter for an aurora altitude of 110 km and a spacecraft altitude of 800 km. In preliminary analysis, a more recent optic has demonstrated a full width at half maximum of 5.0±0.3 arcminutes, corresponding to a footprint of ~1 km from the same spacecraft altitude. We further report the imaging properties of a convex microchannel plate detector with planar resistive anode readout; this detector, whose active surface has a radius of curvature of only 100 mm, is shown to meet the spatial resolution and sensitivity requirements of the new wide field auroral imager (WFAI).

  9. Chorus Wave Scattering Responsible for the Dayside Diffuse Auroral Precipitation

    NASA Astrophysics Data System (ADS)

    Ni, B.; Nishimura, T.; Bortnik, J.; Thorne, R. M.; Li, W.; Angelopoulos, V.; Ebihara, Y.; Weatherwax, A. T.

    2012-12-01

    We perform a comprehensive theoretical and numerical analysis on the conjunction measurements of dayside diffuse aurora and whistler-mode chorus waves by the South Pole all-sky imager and THEMIS spacecraft at 16 -18 UT on August 13, 2009. A high correlation is identified between the intensities of the diffuse aurora at 557.7 nm near the THEMIS ionospheric footprints and chorus emissions. Using the simultaneous wave, plasma density and particle datasets of THEMIS observations, we compute the matrices of bounce-averaged diffusion coefficients due to chorus wave scattering in the realistic magnetosphere at a series of representative time stamps, which are subsequently utilized to quantitatively compare with the rate of strong diffusion for evaluating the energy dependent loss cone filling index associated with chorus-induced pitch angle scattering. Fits of Maxwellian-type energy spectrum to the modeled electron differential fluxes inside the loss cone produce a temporal variation of the total energy flux and characteristic energy of precipitating electrons. The obtained dominant precipitation energies are within 2 - 5 keV, which agrees well with the major electron population for the dayside green-line aurora excitation. The modeled change of the total precipitation energy flux is remarkably consistent with that of the observed green-line diffuse aurora intensity. The trend of decreases and increases in the aurora luminosity is also reasonably reproduced in a time consistent manner. Through a systematic combination of quasi-linear theory, realistic non-dipolar magnetic field mapping, and the concept of strong diffusion on the basis of conjugated space and ground observations, we have demonstrated that dayside chorus scattering can dominantly account for the dayside green-line diffuse aurora activity, while variations in electron differential flux also play a role. In addition, changes in the ambient density can affect the portion of diffuse auroral electrons that

  10. The Faith, Activity, and Nutrition Program

    PubMed Central

    Wilcox, Sara; Parrot, Allen; Baruth, Megan; Laken, Marilyn; Condrasky, Margaret; Saunders, Ruth; Dowda, Marsha; Evans, Rebecca; Addy, Cheryl; Warren, Tatiana Y.; Kinnard, Deborah; Zimmerman, Lakisha

    2013-01-01

    Background Faith-based interventions hold promise for promoting health in ethnic minority populations. To date, however, few of these interventions have used a community-based participatory research (CBPR) approach, have targeted both physical activity and healthy eating, and have focused on structural changes in the church. Purpose To report the results of a group randomized CBPR intervention targeting physical activity and healthy eating in African-American churches. Design Group RCT. Data were collected from 2007 to 2011. Statistical analyses were conducted in 2012. Setting/participants Seventy-four African Methodist Episcopal (AME) churches in South Carolina and 1257 members within them participated in the study. Intervention Churches were randomized to an immediate (intervention) or delayed (control) 15-month intervention that targeted organizational and environmental changes consistent with the structural ecologic model. A CBPR approach guided intervention development. Intervention churches attended a full-day committee training and a full-day cook training. They also received a stipend and 15 months of mailings and technical assistance calls to support intervention implementation. Main outcome measures Primary outcomes were self-reported moderate-to-vigorous-intensity physical activity (MVPA), self-reported fruit and vegetable consumption, and measured blood pressure. Secondary outcomes were self-reported fat- and fiber-related behaviors. Measurements were taken at baseline and 15 months. Intent-to-treat repeated measures ANOVA tested group X time interactions, controlling for church clustering, wave, and size, and participant age, gender, and education. Post hoc ANCOVAs were conducted with measurement completers. Results There was a significant effect favoring the intervention group in self-reported leisure-time MVPA (d=0.18, p=0.02), but no effect for other outcomes. ANCOVA analyses showed an intervention effect for self-reported leisure-time MVPA (d=0

  11. University Program Management Information System: NASA's University Program Active Projects

    NASA Technical Reports Server (NTRS)

    Gans, Gary (Technical Monitor)

    2003-01-01

    As basic policy, NASA believes that colleges and universities should be encouraged to participate in the nation's space and aeronautics program to the maximum extent practicable. Indeed, universities are considered as partners with government and industry in the nation's aerospace program. NASA's objective is to have them bring their scientific, engineering, and social research competence to bear on aerospace problems and on the broader social, economic, and international implications of NASA's technical and scientific programs. It is expected that, in so doing, universities will strengthen both their research and their educational capabilities to contribute more effectively to the national well being. This annual report is one means of documenting the NASA-university relationship, frequently denoted, collectively, as NASA's University Program. This report is consistent with agency accounting records, as the data is obtained from NASA's Financial and Contractual Status (FACS) System, operated by the Financial Management Division and the Procurement Office. However, in accordance with interagency agreements, the orientation differs from that required for financial or procurement purposes. Any apparent discrepancies between this report and other NASA procurement or financial reports stem from the selection criteria for the data. This report was prepared by the Office of Education/N.

  12. Characteristic ion distributions in the dynamic auroral transition region

    NASA Astrophysics Data System (ADS)

    Zeng, W.; Horwitz, J. L.; Tu, J.-N.

    2006-04-01

    A Dynamic Fluid Kinetic (DyFK) simulation is conducted to study the H+/O+ flows and distribution functions in the high-latitude dynamic transition region, specifically from 1000 km to about 4000 km altitude. Here, the collisional-to-collisionless transition region is that region where Coulomb collisions have significant but not dominant effects on the ion distributions. In this study, a simulation flux tube, which extends from 120 km to 3 RE altitude, is assumed to experience a pulse of auroral effects for approximately 20 minutes, including both soft electron precipitation and transverse wave heating, and then according to different geophysical circumstances, either to relax following the cessation of such auroral effects or to be heated further continuously by waves with power at higher frequencies. Our principal purpose in this investigation is to elicit the characteristic ion distribution functions in the auroral transition region, where both collisions and kinetic processes play significant roles. The characteristics of the simulated O+ and H+ velocity distributions, such as kidney bean shaped H+ distributions, and O+ distributions having cold cores with upward folded conic wings, resemble those observed by satellites at similar altitudes and geographic conditions. From the simulated distribution function results under different geophysical conditions, we find that O+-O+ and O+-H+ collisions, in conjunction with the kinetic and auroral processes, are key factors in the velocity distributions up to 4000 km altitude, especially for the low speed portions, for both O+ and H+ ions.

  13. Correlations between solar wind parameters and auroral kilometric radiation intensity

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Dangelo, N.

    1981-01-01

    The relationship between solar wind properties and the influx of energy into the nightside auroral region as indicated by the intensity of auroral kilometric radiation is investigated. Smoothed Hawkeye satellite observations of auroral radiation at 178, 100 and 56.2 kHz for days 160 through 365 of 1974 are compared with solar wind data from the composite Solar Wind Plasma Data Set, most of which was supplied by the IMP-8 spacecraft. Correlations are made between smoothed daily averages of solar wind ion density, bulk flow speed, total IMF strength, electric field, solar wind speed in the southward direction, solar wind speed multiplied by total IMF strength, the substorm parameter epsilon and the Kp index. The greatest correlation is found between solar wind bulk flow speed and auroral radiation intensity, with a linear correlation coefficient of 0.78 for the 203 daily averages examined. A possible mechanism for the relationship may be related to the propagation into the nightside magnetosphere of low-frequency long-wavelength electrostatic waves produced in the magnetosheath by the solar wind.

  14. Auroral nightside downward-current regions: ClusterII observations

    NASA Astrophysics Data System (ADS)

    Lynch, K.; Fazakerley, A.; Karlsson, T.; Lahiff, A.; Marklund, G.

    2007-12-01

    The ClusterII spacecraft traverse the nightside auroral zone at 4-6 Re altitudes in February-March of each year. In 2004, their separation was such as to cross the auroral zone with separation times of a few minutes, comparable to the expected timescales of auroral downward current sheet evolution. We present observations from 12 such events from an effort to look for signatures of the temporal evolution of the auroral downward current system. We compare the electron characteristic energy (ratio of energy flux to number flux) and density of the upgoing electron beams as measured by the PEACE instrument, to electric field signatures from EFW including integrated potential, divergent field structures, and ambient density calculated from the spacecraft potential. The events are seen to be localized on or near ambient density gradients. The characteristic energy of the upgoing electrons is inversely proportional to their number density. Characteristic energies of up to a few keV are seen, and these energies typically decrease with time as subsequent spacecraft cross the same event.

  15. Fractal approach to the description of the auroral region

    SciTech Connect

    Chernyshov, A. A. Mogilevsky, M. M.; Kozelov, B. V.

    2013-07-15

    The plasma of the auroral region, where energetic particles precipitate from the magnetosphere into the ionosphere, is highly inhomogeneous and nonstationary. In this case, traditional methods of classical plasma physics turn out to be inapplicable. In order to correctly describe the dynamic regimes, transition processes, fluctuations, and self-similar scalings in this region, nonlinear dynamics methods based of the concepts of fractal geometry and percolation theory can be used. In this work, the fractal geometry and percolation theory are used to describe the spatial structure of the ionospheric conductivity. The topological properties, fractal dimensions, and connective indices characterizing the structure of the Pedersen and Hall conductivities on the nightside auroral zone are investigated theoretically. The restrictions imposed on the fractal estimates by the condition of ionospheric current percolation are analyzed. It is shown that the fluctuation scalings of the electric fields and auroral glow observed in the auroral zone fit well the restrictions imposed by the critical condition on the percolation of the Pedersen current. Thus, it is demonstrated that the fractal approach is a promising and convenient method for studying the properties of the ionosphere.

  16. Stability within Jupiter's polar auroral 'Swirl region' over moderate timescales

    NASA Astrophysics Data System (ADS)

    Stallard, Tom S.; Clarke, John T.; Melin, Henrik; Miller, Steve; Nichols, Jon D.; O'Donoghue, James; Johnson, Rosie E.; Connerney, John E. P.; Satoh, Takehiko; Perry, Michael

    2016-04-01

    Jupiter's Swirl region, poleward of the main auroral emission, has been characterised in previous observations as having highly variable auroral emission, changing dramatically across the region on a two-minute timescale, the typical integration time for UV images. This variability has made comparisons with H3+ emission difficult. Here, we show that the Swirl region in H3+ images is characterised by relatively stable emission, often with an arc of emission on the boundary between the Swirl and Dark regions. Coadding multiple UV images taken over the approximate lifetime of the H3+ molecule in the ionosphere, show similar structures to those observed in the H3+ images. Our analysis shows that UV auroral morphology within Jupiter's Swirl region is only highly variable on short timescales of ∼100 s, an intrinsic property of the particle precipitation process, but this variability drops away on timescales of 5-15 min. On moderate timescales between 10 and 100 min, the Swirl region is stable, evolving through as yet unknown underlying magnetospheric interactions. This shows that observing the UV aurora over timescales 5-15 min resolves clear auroral structures that will help us understand the magnetospheric origin of these features, and that calculating the variability over different timescales, especially >15 min, provides a new and important new tool in our understanding of Jupiter's polar aurora.

  17. Eyewitness Reports of the Great Auroral Storm of 1859

    NASA Technical Reports Server (NTRS)

    Green, James L.; Boardsen, Scott; Odenwald, Sten; Humble, John; Pazamickas, Katherine A.

    2005-01-01

    The great geomagnetic storm of 1859 is really composed of two closely spaced massive worldwide auroral events. The first event began on August 28th and the second began on September 2nd. It is the storm on September 2nd that results from the Carrington-Hodgson white light flare that occurred on the sun September l&. In addition to published scientific measurements; newspapers, ship logs and other records of that era provide an untapped wealth of first hand observations giving time and location along with reports of the auroral forms and colors. At its height, the aurora was described as a blood or deep crimson red that was so bright that one "could read a newspaper by." Several important aspects of this great geomagnetic storm are simply phenomenal. Auroral forms of all types and colors were observed to latitudes of 25deg and lower. A significant portion of the world's 125,000 miles of telegraph lines were also adversely affected. Many of - which were unusable for 8 hours or more and had a small but notable economic impact. T h s paper presents only a select few available first hand accounts of the Great Auroral Event of 1859 in an attempt to give the modern reader a sense of how this spectacular display was received by the public from many places around the globe and present some other important historical aspects of the storm.

  18. New frontiers in H-Beta auroral photometry

    NASA Astrophysics Data System (ADS)

    Unick, C.; Donovan, E.; Connors, M. G.; Spanswick, E.; Jackel, B. J.; Greffen, M. J.; Wilson, C.; Little, J.; Chaddock, D.; Schofield, I.; MacRae, A.; Chen, S.; Crowther, A.; James, S.; Read, A.; Willis, T.

    2013-12-01

    The proton aurora provides valuable information about magnetotail structure and dynamics. For example, the location of the equatorward boundary of the proton aurora is a robust indicator of magnetotail stretching. Also, proton auroral luminosities combined with in situ ion measurements provide important information about magnetic mapping between the inner CPS and the auroral ionosphere. In this paper, we present a new and innovative proton-auroral (H-Beta) meridian-scanning photometer (MSP) capable of higher spatial and temporal resolution than has been achieved in the past. This H-Beta MSP is the first of a new dual-wavelength (signal/background) MSP design with a single scanning mirror and no other moving parts. The novel filtering architecture allows for a near 100% duty cycle with a 30-second meridian scan and configurable operating modes. The new design is significantly more sensitive than the legacy CANOPUS MSPs. The increased SNR can be employed in a variety of ways, such as to achieve significantly higher time resolution. Here, we present the new instrument design, test data from a commissioning campaign in Athabasca, and some thoughts on how the enhance proton auroral capability can increase the science value of these measurements.

  19. Equatorward evolution of auroras from the poleward auroral boundary

    NASA Astrophysics Data System (ADS)

    Saka, O.; Hayashi, K.; Thomsen, M. F.

    2016-07-01

    An all-sky imager installed at the midnight sector in Dawson City (66.0° in geomagnetic latitude) recorded the equatorward evolution of auroras from the auroral poleward boundary. The auroras evolved as shear layers expanding southeastward with velocities of 1-4 km/s, referred to as N-S auroras, and occurred during the transient intensification of the convection electric fields in the nighttime magnetosphere, as inferred from an electron spectrogram at geosynchronous altitudes. A continuous increase in the inclination angle of the field lines and magnetic field perturbations associated with propagating ionospheric loop currents were observed in the auroral zone during the N-S auroras. Simultaneously, Pc4 pulsations were observed at low latitudes from night to day sectors. We conclude the following: (1) the N-S auroras are an auroral manifestation of the earthward drift of plasma sheet electrons in the equatorial plane associated with transient and localized convection electric fields; (2) the Pc4 pulsations are produced in the magnetosphere by plasma sheet ions in the plasmasphere. The localized convection fields produce a vortical motion of plasmas in the equatorial plane, which may initiate the N-S auroras and ionospheric loop currents in the auroral zone.

  20. Equatorward and poleward expansion of the auroras during auroral substorms

    SciTech Connect

    Nakamura, R. ); Oguti, Takasi ); Yamamoto, Tatsundo ); Kokubun, Susumu )

    1993-04-01

    The authors have used all-sky TV auroral data from a number of different sources to study the formation of the auroral bulge with high spatial and temporal resolution. By linking data sets which cover different parts of the sky they are able to study systematically the development of structures within the poleward expanding bulge. Structures develop to the west, east, and equatorward from a localized region of breakup. To the west a surge develops with a clockwise rotation (when viewed along the magnetic field direction). To the east thin auroral features propagate toward the east. Near the center of the bulge, auroral features develop equatorward, becoming north-south aligned. These and other observations are suggested to be the consequence of the bulge developing along the plasma steamlines as a two cell equipotential distribution. In terms of this model the authors are able to explain the expansions of the bulge in different directions, the observation of pulsating structures in the aurora, and offer explanations of other observations.

  1. Strong Magnetic Field Fluctuations within Filamentary Auroral Density Cavities Interpreted as VLF Saucer Sources

    NASA Technical Reports Server (NTRS)

    Knudsen, D. L.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, Robert F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pincon, J.-L.

    2012-01-01

    The Geoelectrodynamics and Electro-Optical Detection of Electron and SuprathermalIon Currents (GEODESIC) sounding rocket encountered more than 100 filamentary densitycavities associated with enhanced plasma waves at ELF (3 kHz) and VLF (310 kHz)frequencies and at altitudes of 800990 km during an auroral substorm. These cavities weresimilar in size (20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs)observed by previous sounding rockets and satellites; however, in contrast, many of theGEODESIC cavities exhibited up to tenfold enhancements in magnetic wave powerthroughout the VLF band. GEODESIC also observed enhancements of ELF and VLFelectric fields both parallel and perpendicular to the geomagnetic field B0 within cavities,though the VLF E field increases were often not as large proportionally as seen in themagnetic fields. This behavior is opposite to that predicted by previously published theoriesof LHCs based on passive scattering of externally incident auroral hiss. We argue thatthe GEODESIC cavities are active wave generation sites capable of radiating VLF wavesinto the surrounding plasma and producing VLF saucers, with energy supplied by cold,upward flowing electron beams composing the auroral return current. This interpretation issupported by the observation that the most intense waves, both inside and outside cavities,occurred in regions where energetic electron precipitation was largely inhibited orabsent altogether. We suggest that the wave-enhanced cavities encountered by GEODESICwere qualitatively different from those observed by earlier spacecraft because of thefortuitous timing of the GEODESIC launch, which placed the payload at apogee within asubstorm-related return current during its most intense phase, lasting only a few minutes.

  2. Strong magnetic field fluctuations within filamentary auroral density cavities interpreted as VLF saucer sources

    NASA Astrophysics Data System (ADS)

    Knudsen, D. J.; Kabirzadeh, R.; Burchill, J. K.; Pfaff, R. F.; Wallis, D. D.; Bounds, S. R.; Clemmons, J. H.; Pinçon, J.-L.

    2012-02-01

    The Geoelectrodynamics and Electro-Optical Detection of Electron and Suprathermal Ion Currents (GEODESIC) sounding rocket encountered more than 100 filamentary density cavities associated with enhanced plasma waves at ELF (<3 kHz) and VLF (3-10 kHz) frequencies and at altitudes of 800-990 km during an auroral substorm. These cavities were similar in size (˜20 m diameter in most cases) to so-called lower-hybrid cavities (LHCs) observed by previous sounding rockets and satellites; however, in contrast, many of the GEODESIC cavities exhibited up to tenfold enhancements in magnetic wave power throughout the VLF band. GEODESIC also observed enhancements of ELF and VLF electric fields both parallel and perpendicular to the geomagnetic field B0 within cavities, though the VLF E field increases were often not as large proportionally as seen in the magnetic fields. This behavior is opposite to that predicted by previously published theories of LHCs based on passive scattering of externally incident auroral hiss. We argue that the GEODESIC cavities are active wave generation sites capable of radiating VLF waves into the surrounding plasma and producing VLF saucers, with energy supplied by cold, upward flowing electron beams composing the auroral return current. This interpretation is supported by the observation that the most intense waves, both inside and outside cavities, occurred in regions where energetic electron precipitation was largely inhibited or absent altogether. We suggest that the wave-enhanced cavities encountered by GEODESIC were qualitatively different from those observed by earlier spacecraft because of the fortuitous timing of the GEODESIC launch, which placed the payload at apogee within a substorm-related return current during its most intense phase, lasting only a few minutes.

  3. Nonlinear interactions of electromagnetic waves with the auroral ionosphere

    SciTech Connect

    Wong, Alfred Y.

    1999-09-20

    The ionosphere provides us with an opportunity to perform plasma experiments in an environment with long confinement times, very large-scale lengths, and no confining walls. The auroral ionosphere with its nearly vertical magnetic field geometry is uniquely endowed with large amount of free energy from electron and ion precipitation along the magnetic field and mega-ampere current across the magnetic field. To take advantage of this giant outdoor laboratory, two facilities HAARP and HIPAS, with frequencies ranging from the radio to optical bands, are now available for active probing of and interaction with this interesting region. The ponderomotive pressures from the self-consistent wave fields have produced significant local perturbations of density and particle distributions at heights where the incident EM frequency matches a plasma resonance. This paper will review theory and experiments covering the nonlinear phenomena of parametric decay instability to wave collapse processes. At HF frequencies plasma lenses can be created by preconditioning pulses to focus what is a normally divergent beam into a high-intensity spot to further enhance nonlinear phenomena. At optical wavelengths a large rotating liquid metal mirror is used to focus laser pulses up to a given height. Such laser pulses are tuned to the same wavelengths of selected atomic and molecular resonances, with resulting large scattering cross sections. Ongoing experiments on dual-site experiments and excitation of ELF waves will be presented. The connection of such basic studies to environmental applications will be discussed. Such applications include the global communication using ELF waves, the ozone depletion and remediation and the control of atmospheric CO{sub 2} through the use of ion cyclotron resonant heating.

  4. Theoretical and experimental studies relevant to interpretation of auroral emissions

    NASA Technical Reports Server (NTRS)

    Keffer, Charles E.

    1991-01-01

    The accomplishments achieved over the past year are detailed with emphasis on the interpretation or auroral emissions and studies of potential spacecraft-induced contamination effects. Accordingly, the research was divided into two tasks. The first task is designed to add to the understanding of space vehicle induced external contamination. An experimental facility for simulation of the external environment for a spacecraft in low earth orbit was developed. The facility was used to make laboratory measurements of important phenomena required for improving the understanding of the space vehicle induced external environment and its effect on measurement of auroral emissions from space-based platforms. A workshop was sponsored to provide a forum for presentation of the latest research by nationally recognized experts on space vehicle contamination and to discuss the impact of this research on future missions involving space-based platforms. The second task is to add an ab initio auroral calculation to the extant ionospheric/thermospheric global modeling capabilities. Once the addition of the code was complete, the combined model was to be used to compare the relative intensities and behavior of various emission sources (dayglow, aurora, etc.). Such studies are essential to an understanding of the types of vacuum ultraviolet (VUV) auroral images which are expected to be available within two years with the successful deployment of the Ultraviolet Imager (UVI) on the ISTP POLAR spacecraft. In anticipation of this, the second task includes support for meetings of the science working group for the UVI to discuss operational and data analysis needs. Taken together, the proposed tasks outline a course of study designed to make significant contributions to the field of space-based auroral imaging.

  5. Modes of high-latitude auroral conductance variability derived from DMSP energetic electron precipitation observations: Empirical orthogonal function analysis

    NASA Astrophysics Data System (ADS)

    McGranaghan, Ryan; Knipp, Delores J.; Matsuo, Tomoko; Godinez, Humberto; Redmon, Robert J.; Solomon, Stanley C.; Morley, Steven K.

    2015-12-01

    We provide the first ever characterization of the primary modes of ionospheric Hall and Pedersen conductance variability as empirical orthogonal functions (EOFs). These are derived from six satellite years of Defense Meteorological Satellite Program (DMSP) particle data acquired during the rise of solar cycles 22 and 24. The 60 million DMSP spectra were each processed through the Global Airlglow Model. Ours is the first large-scale analysis of ionospheric conductances completely free of assumption of the incident electron energy spectra. We show that the mean patterns and first four EOFs capture ˜50.1 and 52.9% of the total Pedersen and Hall conductance variabilities, respectively. The mean patterns and first EOFs are consistent with typical diffuse auroral oval structures and quiet time strengthening/weakening of the mean pattern. The second and third EOFs show major disturbance features of magnetosphere-ionosphere (MI) interactions: geomagnetically induced auroral zone expansion in EOF2 and the auroral substorm current wedge in EOF3. The fourth EOFs suggest diminished conductance associated with ionospheric substorm recovery mode. We identify the most important modes of ionospheric conductance variability. Our results will allow improved modeling of the background error covariance needed for ionospheric assimilative procedures and improved understanding of MI coupling processes.

  6. 36 CFR 1211.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 3 2012-07-01 2012-07-01 false Education programs or... ADMINISTRATION GENERAL RULES NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  7. 44 CFR 19.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 44 Emergency Management and Assistance 1 2014-10-01 2014-10-01 false Education programs or..., DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  8. 44 CFR 19.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 44 Emergency Management and Assistance 1 2012-10-01 2011-10-01 true Education programs or..., DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  9. 36 CFR 1211.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 3 2013-07-01 2012-07-01 true Education programs or... ADMINISTRATION GENERAL RULES NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  10. 44 CFR 19.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 44 Emergency Management and Assistance 1 2013-10-01 2013-10-01 false Education programs or..., DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  11. 36 CFR 1211.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 36 Parks, Forests, and Public Property 3 2014-07-01 2014-07-01 false Education programs or... ADMINISTRATION GENERAL RULES NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  12. Design for Diversity: A Program Planning Grid for Student Activities.

    ERIC Educational Resources Information Center

    Kubik, Jan B.

    This guide provides a program planning grid for college student personnel workers involved in the area of student activities. A program planning and evaluative system is proposed to address campus needs and allow greater control in planning an educationally balanced program. This system is based on an outline of topical areas to be addressed…

  13. 20 CFR 631.51 - Allowable substate program activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Allowable substate program activities. 631.51 Section 631.51 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE III OF THE JOB TRAINING PARTNERSHIP ACT Substate Programs § 631.51 Allowable...

  14. 20 CFR 631.51 - Allowable substate program activities.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 3 2012-04-01 2012-04-01 false Allowable substate program activities. 631.51 Section 631.51 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE III OF THE JOB TRAINING PARTNERSHIP ACT Substate Programs § 631.51 Allowable...

  15. 36 CFR 1211.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Education programs or... ADMINISTRATION GENERAL RULES NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or...

  16. 44 CFR 19.400 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Education programs or..., DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs...

  17. Medically related activities of application team program

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Application team methodology identifies and specifies problems in technology transfer programs to biomedical areas through direct contact with users of aerospace technology. The availability of reengineering sources increases impact of the program on the medical community and results in broad scale application of some bioinstrumentation systems. Examples are given that include devices adapted to the rehabilitation of neuromuscular disorders, power sources for artificial organs, and automated monitoring and detection equipment in clinical medicine.

  18. Auroral electrojets during deep solar minimum at the end of solar cycle 23

    NASA Astrophysics Data System (ADS)

    Pulkkinen, T. I.; Tanskanen, E. I.; Viljanen, A.; Partamies, N.; Kauristie, K.

    2011-04-01

    We investigate the auroral electrojet activity during the deep minimum at the end of solar cycle 23 (2008-2009) by comparing data from the IMAGE magnetometer chain, auroral observations in Fennoscandia and Svalbard, and solar wind and interplanetary magnetic field (IMF) observations from the OMNI database from that period with those recorded one solar cycle earlier. We examine the eastward and westward electrojets and the midnight sector separately. The electrojets during 2008-2009 were found to be weaker and at more poleward latitudes than during other times, but when similar driving solar wind and IMF conditions are compared, the behavior in the morning and evening sectors during 2008-2009 was similar to other periods. On the other hand, the midnight sector shows distinct behavior during 2008-2009: for similar driving conditions, the electrojets resided at further poleward latitudes and on average were weaker than during other periods. Furthermore, the substorm occurrence frequency seemed to saturate to a minimum level for very low levels of driving during 2009. This analysis suggests that the solar wind coupling to the ionosphere during 2008-2009 was similar to other periods but that the magnetosphere-ionosphere coupling has features that are unique to this period of very low solar activity.

  19. Coherence scales of wavefield during propagation through naturally disturbed ionosphere in the polar cap, auroral, and equatorial regions

    SciTech Connect

    Basu, S.; Basu, S.; Livingston, R.C.

    1990-05-03

    Phase and intensity scintillation measurements have been made at low latitudes in the equatorial anomaly region, and at high latitudes in the auroral oval and the polar cap regions, using phase coherent transmissions at 250 MHz from stationary and near stationary satellites. The observations pertain to periods of high solar activity when intense scintillation activity is recorded at each of the above observing sites. This data set has been utilized to study the reduction of coherence times of intensity and complex amplitude scintillation with increasing strength of scattering. Estimates of coherence scales of intensity and complex amplitude scintillation at 250 MHz are provided which indicate that coherent scales of scintillation are typically of the order of hundreds of meters at high latitudes but approach values as small as tens of meters in the equatorial anomaly region. The phase spectral index in the nightside auroral oval is observed to be much steeper (p sub psi = .4) than those typically observed in the equatorial (p sub psi = 2.4) or polar cap regions (p sub psi approx. -2.3). It shows the importance of large scale phase variations in the nightside auroral oval. Under strong scatter conditions, the coherence times of complex amplitude scintillation are shown to asymptotically approach a value which is 1.4 times the coherence time of intensity scintillation. This result is consistent with the theoretical predictions for Rayleigh statistics.

  20. Auroras Now! - Auroral nowcasting service for Hotels in Finnish Lapland and its performance during winter 2003-2004

    NASA Astrophysics Data System (ADS)

    Kauristie, K.; Mälkki, A.; Pulkkinen, A.; Nevanlinna, H.; Ketola, A.; Tulkki, V.; Raita, T.; Blanco, A.

    2004-12-01

    European Space Agency is currently supporting 17 Service Development Activities (SDA) within its Space Weather Pilot Project. Auroras Now!, one of the SDAs, has been operated during November 2003 - March 2004 as its pilot season. The service includes a public part freely accessible in Internet (http://aurora.fmi.fi) and a private part visible only to the customers of two hotels in the Finnish Lapland through the hotels' internal TV-systems. The nowcasting system is based on the magnetic recordings of two geophysical observatories, Sodankylä (SOD, MLAT ~64 N) and Nurmijärvi (NUR, MLAT ~57 N). The probability of auroral occurrence is continuously characterised with an empirically determined three-level scale. The index is updated once per hour and based on the magnetic field variations recorded at the observatories. During dark hours the near-real time auroral images acquired at SOD are displayed. The hotel service also includes cloudiness predictions for the coming night. During the pilot season the reliability of the three-level magnetic alarm system was weekly evaluated by comparing its prediction with auroral observations by the nearby all-sky camera. Successful hits and failures were scored according to predetermined rules. The highest credit points when it managed to spot auroras in a timely manner and predict their brightness correctly. Maximum penalty points were given when the alarm missed clear bright auroras lasting for more than one hour. In this presentation we analyse the results of the evaluation, present some ideas to further sharpen the procedure, and discuss more generally the correlation between local auroral and magnetic activity.

  1. Activities for a Perceptual Motor Program.

    ERIC Educational Resources Information Center

    Brinning, Dorothy; And Others

    Perceptual motor activities for physically handicapped children are presented in the areas of fine and gross motor skills. Also detailed are activities to develop body image, visual motor skills, and tactile and auditory perception. (JD)

  2. 49 CFR 25.400 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 25.400 Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX... Basis of Sex in Education Programs or Activities Prohibited § 25.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  3. Perceptions and Evaluation of a Physical Activity Program

    ERIC Educational Resources Information Center

    Smith, Gene A.

    2012-01-01

    This qualitative case study, conducted in the Midwestern United States, explored the perceptions of teachers at two different elementary schools as they implemented a physical activity program during the school day. The program engaged students in daily physical activity through brief, organized, structured physical exercise. Interviews and…

  4. 34 CFR 106.31 - Education programs or activities.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 1 2013-07-01 2013-07-01 false Education programs or activities. 106.31 Section 106.31 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING...

  5. 34 CFR 106.31 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 1 2012-07-01 2012-07-01 false Education programs or activities. 106.31 Section 106.31 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING...

  6. 34 CFR 106.31 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 1 2014-07-01 2014-07-01 false Education programs or activities. 106.31 Section 106.31 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING...

  7. 32 CFR 196.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) MISCELLANEOUS NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities... Title IX regulations, no person shall, on the basis of sex, be excluded from participation in, be...

  8. 36 CFR 1211.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ADMINISTRATION GENERAL RULES NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities... Title IX regulations, no person shall, on the basis of sex, be excluded from participation in, be...

  9. 22 CFR 146.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Section 146.400 Foreign Relations DEPARTMENT OF STATE CIVIL RIGHTS NONDISCRIMINATION ON THE BASIS OF SEX... Basis of Sex in Education Programs or Activities Prohibited § 146.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  10. 24 CFR 3.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Urban Development NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities... IX regulations, no person shall, on the basis of sex, be excluded from participation in, be...

  11. 13 CFR 113.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ADMINISTRATOR Nondiscrimination on the Basis of Sex in Education Programs or Activities Receiving Federal Financial Assistance Discrimination on the Basis of Sex in Education Programs Or Activities Prohibited § 113... regulations, no person shall, on the basis of sex, be excluded from participation in, be denied the...

  12. 49 CFR 25.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 25.400 Transportation Office of the Secretary of Transportation NONDISCRIMINATION ON THE BASIS OF SEX... Basis of Sex in Education Programs or Activities Prohibited § 25.400 Education programs or activities... basis of sex, be excluded from participation in, be denied the benefits of, or be subjected...

  13. 38 CFR 23.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 23... regulations, no person shall, on the basis of sex, be excluded from participation in, be denied the...

  14. 45 CFR 2555.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... COMMUNITY SERVICE NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities... Title IX regulations, no person shall, on the basis of sex, be excluded from participation in, be...

  15. 34 CFR 106.31 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or Activities Prohibited § 106... person shall, on the basis of sex, be excluded from participation in, be denied the benefits of, or...

  16. 34 CFR 106.31 - Education programs or activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Education programs or activities. 106.31 Section 106.31 Education Regulations of the Offices of the Department of Education OFFICE FOR CIVIL RIGHTS, DEPARTMENT OF EDUCATION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING...

  17. Activities in Environmental Education. Environmental Studies Program.

    ERIC Educational Resources Information Center

    Owens, Michael

    This guide describes 38 activities appropriate for grades K-12. Each activity contains a brief description of the activity and a list of materials needed. The second section of the guide contains environmental learning games to be played in the classroom. These games include: crossword puzzles, cryptograms, logic problems, card games, and…

  18. Conservation Seeds Activities Book. An Early Childhood Conservation Education Program.

    ERIC Educational Resources Information Center

    Griffin, Sherri

    This activities book is used with an early childhood conservation education program. The activities are presented in four color-coded sections, each section representing one of the four seasons. Each activity includes a statement of purpose, list of materials needed, instructional strategies, and a list of supplementary activities. In addition to…

  19. Overview of the Novel Intelligent JAXA Active Rotor Program

    NASA Technical Reports Server (NTRS)

    Saito, Shigeru; Kobiki, Noboru; Tanabe, Yasutada; Johnson, Wayne; Yamauchi, Gloria K.; Young, Larry A.

    2010-01-01

    The Novel Intelligent JAXA Active Rotor (NINJA Rotor) program is a cooperative effort between JAXA and NASA, involving a test of a JAXA pressure-instrumented, active-flap rotor in the 40- by 80-Foot Wind Tunnel at Ames Research Center. The objectives of the program are to obtain an experimental database of a rotor with active flaps and blade pressure instrumentation, and to use that data to develop analyses to predict the aerodynamic and aeroacoustic performance of rotors with active flaps. An overview of the program is presented, including a description of the rotor and preliminary pretest calculations.

  20. Activities for numerical propulsion systems simulation program

    NASA Technical Reports Server (NTRS)

    Evans, Austin L.

    1992-01-01

    The Interdisciplinary Technology Office (ITO) has been tasked with the responsibility of coordinating interdisciplinary research and technology programs; establish and maintain interface with the various disciplines at LeRC, industry, government, and academic organizations; and facilitating the exploitation of advances in the individual disciplinary efforts that have multidisciplinary implications.

  1. On the formation and origin of substorm growth phase/onset auroral arcs inferred from conjugate space-ground observations

    SciTech Connect

    Motoba, T.; Ohtani, S.; Anderson, B. J.; Korth, H.; Mitchell, D.; Lanzerotti, L. J.; Shiokawa, K.; Connors, M.; Kletzing, C. A.; Reeves, G. D.

    2015-10-27

    In this study, magnetotail processes and structures related to substorm growth phase/onset auroral arcs remain poorly understood mostly due to the lack of adequate observations. In this study we make a comparison between ground-based optical measurements of the premidnight growth phase/onset arcs at subauroral latitudes and magnetically conjugate measurements made by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) at ~780 km in altitude and by the Van Allen Probe B (RBSP-B) spacecraft crossing L values of ~5.0–5.6 in the premidnight inner tail region. The conjugate observations offer a unique opportunity to examine the detailed features of the arc location relative to large-scale Birkeland currents and of the magnetospheric counterpart. Our main findings include (1) at the early stage of the growth phase the quiet auroral arc emerged ~4.3° equatorward of the boundary between the downward Region 2 (R2) and upward Region 1 (R1) currents; (2) shortly before the auroral breakup (poleward auroral expansion) the latitudinal separation between the arc and the R1/R2 demarcation narrowed to ~1.0°; (3) RBSP-B observed a magnetic field signature of a local upward field-aligned current (FAC) connecting the arc with the near-Earth tail when the spacecraft footprint was very close to the arc; and (4) the upward FAC signature was located on the tailward side of a local plasma pressure increase confined near L ~5.2–5.4. These findings strongly suggest that the premidnight arc is connected to highly localized pressure gradients embedded in the near-tail R2 source region via the local upward FAC.

  2. Observations of vertical winds and the origin of thermospheric gravity waves launched by auroral substorms and westward travelling surges

    NASA Technical Reports Server (NTRS)

    Rees, D.

    1986-01-01

    Several sequences of observations of strong vertical winds in the upper thermosphere are discussed, in conjunction with models of the generation of such winds. In the auroral oval, the strongest upward winds are observed in or close to regions of intense auroral precipitation and strong ionospheric currents. The strongest winds, of the order of 100 to 200 m/sec are usually upward, and are both localized and of relatively short duration (10 to 20 min). In regions adjacent to those displaying strong upward winds, and following periods of upward winds, downward winds of rather lower magnitude (40 to about 80 m/sec) may be observed. Strong and rapid changes of horizontal winds are correlated with these rapid vertical wind variations. Considered from a large scale viewpoint, this class of strongly time dependent winds propagate globally, and may be considered to be gravity waves launched from an auroral source. During periods of very disturbed geomagnetic activity, there may be regions within and close to the auroral oval where systematic vertical winds of the order of 50 m/sec will occur for periods of several hours. Such persistent winds are part of a very strong large scale horizontal wind circulation set up in the polar regions during a major geomagnetic disturbance. This second class of strong horizontal and vertical winds corresponds more to a standing wave than to a gravity wave, and it is not as effective as the first class in generating large scale propagating gravity waves and correlated horizontal and vertical oscillations. A third class of significant (10 to 30 m/sec) vertical winds can be associated with systematic features of the average geomagnetic energy and momentum input to the polar thermosphere, and appear in statistical studies of the average vertical wind as a function of Universal Time at a given location.

  3. On the formation and origin of substorm growth phase/onset auroral arcs inferred from conjugate space-ground observations

    DOE PAGES

    Motoba, T.; Ohtani, S.; Anderson, B. J.; Korth, H.; Mitchell, D.; Lanzerotti, L. J.; Shiokawa, K.; Connors, M.; Kletzing, C. A.; Reeves, G. D.

    2015-10-27

    In this study, magnetotail processes and structures related to substorm growth phase/onset auroral arcs remain poorly understood mostly due to the lack of adequate observations. In this study we make a comparison between ground-based optical measurements of the premidnight growth phase/onset arcs at subauroral latitudes and magnetically conjugate measurements made by the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) at ~780 km in altitude and by the Van Allen Probe B (RBSP-B) spacecraft crossing L values of ~5.0–5.6 in the premidnight inner tail region. The conjugate observations offer a unique opportunity to examine the detailed features of the arcmore » location relative to large-scale Birkeland currents and of the magnetospheric counterpart. Our main findings include (1) at the early stage of the growth phase the quiet auroral arc emerged ~4.3° equatorward of the boundary between the downward Region 2 (R2) and upward Region 1 (R1) currents; (2) shortly before the auroral breakup (poleward auroral expansion) the latitudinal separation between the arc and the R1/R2 demarcation narrowed to ~1.0°; (3) RBSP-B observed a magnetic field signature of a local upward field-aligned current (FAC) connecting the arc with the near-Earth tail when the spacecraft footprint was very close to the arc; and (4) the upward FAC signature was located on the tailward side of a local plasma pressure increase confined near L ~5.2–5.4. These findings strongly suggest that the premidnight arc is connected to highly localized pressure gradients embedded in the near-tail R2 source region via the local upward FAC.« less

  4. A multi-scale magnetotail reconnection event at Saturn and associated flows: Cassini/UVIS auroral observations

    NASA Astrophysics Data System (ADS)

    Radioti, Aikaterini; Grodent, Denis; Jia, Xianzhe; Gérard, Jean-Claude; Bonfond, Bertrand; Pryor, Wayne; Gustin, Jacques; Mitchell, Donald; Jackman, Caitriona

    2015-04-01

    We present high-resolution Cassini/UVIS (Ultraviolet Imaging Spectrograph) observations of Saturn's aurora during May 2013 (DOY 140-141). The observations reveal an enhanced auroral activity in the midnight-dawn quadrant in an extended local time sector (~02 to 05 LT), which rotates with an average velocity of ~ 45% of rigid corotation. The auroral dawn enhancement reported here, given its observed location and brightness, is most probably due to hot tenuous plasma carried inward in fast moving flux tubes returning from a tail reconnection site to the dayside. These flux tubes could generate intense field-aligned currents that would cause aurora to brighten. However, the origin of tail reconnection (solar wind or internally driven) is uncertain. Based mainly on the flux variations, which do not demonstrate flux closure, we suggest that the most plausible scenario is that of internally driven tail reconnection which operates on closed field lines. The observations also reveal multiple intensifications within the enhanced region suggesting an x-line in the tail, which extends from 02 to 05 LT. The localised enhancements evolve in arc and spot-like small scale features, which resemble vortices mainly in the beginning of the sequence. These auroral features could be related to plasma flows enhanced from reconnection which diverge into multiple narrow channels then spread azimuthally and radially. We suggest that the evolution of tail reconnection at Saturn may be pictured by an ensemble of numerous narrow current wedges or that inward transport initiated in the reconnection region could be explained by multiple localised flow burst events. The formation of vortical-like structures could then be related to field-aligned currents, building up in vortical flows in the tail. An alternative, but less plausible, scenario could be that the small scale auroral structures are related to viscous interactions involving small-scale reconnection.

  5. Probing Io's putative global magma ocean through FUV auroral spot morphology

    NASA Astrophysics Data System (ADS)

    Roth, Lorenz

    2013-10-01

    Whether Io possesses a magma ocean or not is a central issue for understanding the most volcanically active body in our solar system and is a long standing question as well. Khurana et al., Science 2011, recently substantiated the existence of a highly conductive magma layer inside Io's interior based on Galileo magnetometer measurements and techniques similar to those used to probe the crusts of Europa, Ganymede, and Callisto for liquid water oceans. If a global magma ocean modifies Io's local magnetic field environment, it will also significantly alter the morphology of Io's UV aurora. The most prominent aurora features are two bright spots that rock around the equator roughly in correlation with the varying orientation of the tilted Jovian magnetic field. Magnetic induction in a magma ocean would strongly attenuate the rocking of these near-surface spots. Interestingly, in previous STIS FUV observations the measured spot locations disagree considerably from the locations theoretically predicted for the global magma ocean case, but are in reasonable agreement if there is no ocean. However, the temporal and orbital coverage of Io's rocking auroral spots for the STIS dataset is presently insufficient to conclusively exclude or further investigate the molten magma layer idea. We therefore propose two visits of five consecutive STIS orbits to trend the auroral spot feature locations over a full variation cycle of the Jovian magnetic field near western elongation. This investigation will decisively constrain the molten magma layer inside Io and tests the putative evidence for a global ocean by Khurana et al. {2011}.

  6. Alaskan Auroral All-Sky Images on the World Wide Web

    NASA Technical Reports Server (NTRS)

    Stenbaek-Nielsen, H. C.

    1997-01-01

    In response to a 1995 NASA SPDS announcement of support for preservation and distribution of important data sets online, the Geophysical Institute, University of Alaska Fairbanks, Alaska, proposed to provide World Wide Web access to the Poker Flat Auroral All-sky Camera images in real time. The Poker auroral all-sky camera is located in the Davis Science Operation Center at Poker Flat Rocket Range about 30 miles north-east of Fairbanks, Alaska, and is connected, through a microwave link, with the Geophysical Institute where we maintain the data base linked to the Web. To protect the low light-level all-sky TV camera from damage due to excessive light, we only operate during the winter season when the moon is down. The camera and data acquisition is now fully computer controlled. Digital images are transmitted each minute to the Web linked data base where the data are available in a number of different presentations: (1) Individual JPEG compressed images (1 minute resolution); (2) Time lapse MPEG movie of the stored images; and (3) A meridional plot of the entire night activity.

  7. Ionospheric scintillations and in-situ measurements at an auroral location in the European sector

    SciTech Connect

    Basu, S.; Basu, S.; MacKenzie, E.; Weimer, D.

    1987-05-01

    The orbiting HiLat satellite offered a unique opportunity for studying the ionospheric scintillation parameters in relation to the in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. This paper discusses the results of such a morphological study based on observations at the auroral-oval station of Tromso, Norway. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. The geometrical enhancement of scintillations observed during the alignment of the propagation path with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime auroral oval. The steepening of phase spectral slope in this region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variational of total electron content (TEC) determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also utilized to illustrate the dependence of ionospheric structure parameters on short-term variability of solar activity during the sunspot minimum period. Special effort is made to illustrate that the joint study of scintillation/TEC and in-situ parameters provides an insight into the nature of magnetospheric coupling with the high-latitude ionosphere.

  8. What Can be Learned from the Absence of Auroral X-Ray Emission from Saturn?

    SciTech Connect

    Hui, Yawei; Cravens, Thomas E. E.; Ozak, Nataly; Schultz, David Robert

    2010-01-01

    To understand the origin and magnitude of the present upper limit observations of Saturn's auroral X-ray emission, we use simple models based on the mechanism that leads to analogous emission at Jupiter, charge transfer between ion precipitation and atmospheric gas. Several putative sources and characteristics of the precipitation are considered, namely, (1) highly charged solar wind ions with additional acceleration and (2) ambient, thermal ion population originating, for example, from Saturn's satellites, and then accelerated to high energies. Estimates obtained for each of these sources show the need for acceleration, either to focus the highly charged solar wind ions into the atmosphere or to enable stripping of the initially low-charge state ambient ions to higher charges. The former yields a constraint on the existing accelerating potentials present at Saturn but can only account for about a tenth of the observed upper limit to the auroral luminosity, while the latter requires extremely low limits on the area (i.e., less than 100 km{sup 2}) over which field-aligned potentials are active and needed to produce the acceleration to generate the observational upper limit on the X-ray luminosity. We therefore narrow the range of possible ion sources, the accelerating potentials required that are consistent with the present understanding of the magnetosphere, and model upper limit of X-ray emission from ion precipitation.

  9. Promoting Physical Activity in Afterschool Programs

    ERIC Educational Resources Information Center

    Beighle, Aaron; Beets, Michael W.; Erwin, Heather E.; Huberty, Jennifer; Moore, Justin B.; Stellino, Megan

    2010-01-01

    Children in the United States are not engaging in sufficient amounts of routine physical activity, and this lack is an emerging public health concern (Strong, Malina, Blimkie, Daniels, Dishman, Gutin, et al., 2005). Efforts to increase the physical activity levels of children and adolescents has become a national priority, attracting attention…

  10. Environmental Education Activities & Programs 1998-1999.

    ERIC Educational Resources Information Center

    Bureau of Reclamation (Dept. of Interior), Denver, CO.

    This document features descriptions of interactive learning models and presentations in environmental education concerning groundwater, geology, the environment, weather, water activities, and interactive games. Activities include: (1) GW-Standard; (2) GW-w/no Leaky Underground Storage Tank (No UST); (3) GW-Karst; (4) GW-Landfill Models--Standard…

  11. Cross-field current instability for auroral bead formation in breakup arcs

    NASA Astrophysics Data System (ADS)

    Lui, A. T. Y.

    2016-06-01

    The physical process responsible for the onset of substorm expansion is still unresolved in spite of decades of research on the topic. Detailed properties of the spatially periodic auroral beads on prebreakup auroral arcs that initiate substorm expansion onset are now available. These auroral bead properties impose severe observational constraints on the onset process. In this work, theoretical predictions of the cross-field current instability are evaluated in terms of these constraints. The growth rates and wavelengths associated with auroral beads in several previously published events are reproduced by the cross-field current instability, implying that the instability can indeed account for the characteristics of auroral beads that eventually lead to substorm onset. The present results differ from the conclusion reached by a previous analysis that the shear flow ballooning instability can account for the growth and spatial scales of auroral beads better than the cross-field current instability.

  12. MLS student active learning within a "cloud" technology program.

    PubMed

    Tille, Patricia M; Hall, Heather

    2011-01-01

    In November 2009, the MLS program in a large public university serving a geographically large, sparsely populated state instituted an initiative for the integration of technology enhanced teaching and learning within the curriculum. This paper is intended to provide an introduction to the system requirements and sample instructional exercises used to create an active learning technology-based classroom. Discussion includes the following: 1.) define active learning and the essential components, 2.) summarize teaching methods, technology and exercises utilized within a "cloud" technology program, 3.) describe a "cloud" enhanced classroom and programming 4.) identify active learning tools and exercises that can be implemented into laboratory science programs, and 5.) describe the evaluation and assessment of curriculum changes and student outcomes. The integration of technology in the MLS program is a continual process and is intended to provide student-driven active learning experiences.

  13. A simple kinetic theory of auroral arc scales

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.

    1986-01-01

    A kinetic theory of the origins of the auroral arc scale spectrum is presented in this paper. The conceptual basis of the theory is current conservation in a turbulent plasma at the magnetospheric equatorial region in which a field-aligned current is generated and the local electrostatic potential structure is forced to adjust to the presence of the field-aligned current. This simple model uses an ad hoc Ohm's law relationship between the perpendicular current and the perpendicular electric field, but with a negative conductance in the generator region so that J(perpendicular) x E(perpendicular) is less than 0. An exact solution of a simple model of the concept yields a bistatic auroral generator for which multiple-arc formation is predicted if the field-aligned current exceeds a critical value. The predicted scale spectrum is inversely proportional to the square root of the field-aligned current strength spectrum.

  14. An auroral effect on the fair weather electric field

    NASA Technical Reports Server (NTRS)

    Hale, L. C.; Croskey, C. L.

    1979-01-01

    Evidence is presented for coupling between the upper and lower atmosphere by means of the shorting out of the vertical mesospheric electric field by auroral radiation, which causes a transfer of mesospheric potential to the lower atmosphere. Measurements were made by an electric field antenna which was part of a parachute-borne payload, launched by rocket from near Fairbanks, Alaska. Data obtained from quiet time observations indicate the normal low altitude electric field pattern, with a greater field at high altitudes, while observations at disturbed times show a small field at high altitudes and a greater field at low altitudes. Means for observing this effect at lower latitudes are also suggested. While the data obtained support the proposed mechanism, it is noted that other mechanisms, such as direct modulation by large amounts of solar cosmic rays and aurorally produced charge separation, may also be important.

  15. Asymmetric auroral intensities in the Earth's Northern and Southern hemispheres

    NASA Astrophysics Data System (ADS)

    Laundal, K. M.; Østgaard, N.

    2009-07-01

    It is commonly assumed that the aurora borealis (Northern Hemisphere) and aurora australis (Southern Hemisphere) are mirror images of each other because the charged particles causing the aurora follow the magnetic field lines connecting the two hemispheres. The particles are believed to be evenly distributed between the two hemispheres, from the source region in the equatorial plane of the magnetosphere. Although it has been shown that similar auroral features in the opposite hemispheres can be displaced tens of degree in longitude and that seasonal effects can cause differences in global intensity, the overall auroral patterns were still similar. Here we report observations that clearly contradict the common assumption about symmetric aurora: intense spots are seen at dawn in the Northern summer Hemisphere, and at dusk in the Southern winter Hemisphere. The asymmetry is interpreted in terms of inter-hemispheric currents related to seasons, which have been predicted but hitherto had not been seen.

  16. Auroral electrostatic solitons and supersolitons in a magnetized nonthermal plasma

    SciTech Connect

    Rufai, O. R.

    2015-05-15

    Exploiting the spacecraft measurements in the auroral region, finite amplitude nonlinear low frequency electrostatic solitons and supersolitons in a magnetized plasma consisting of cold ions fluid, Boltzmann protons, and nonthermal hot electrons are studied by applying a pseudo-potential technique. The localized solution of the nonlinear structures is obtained through the charge neutrality condition. Further numerical investigation shows the existence of supersoliton solutions at supersonic Mach numbers regime. The amplitude of ion-acoustic structures decreased with an increase in nonthermal electrons and ion density ratio. For the plasma parameters relevant to the auroral zone of the Earth's magnetosphere, the electric field amplitude of supersolitons is found to be about 9 mV/m, which is in agreement with satellite observations.

  17. Weakening of Jupiter's main auroral emission during January 2014

    NASA Astrophysics Data System (ADS)

    Badman, S. V.; Bonfond, B.; Fujimoto, M.; Gray, R. L.; Kasaba, Y.; Kasahara, S.; Kimura, T.; Melin, H.; Nichols, J. D.; Steffl, A. J.; Tao, C.; Tsuchiya, F.; Yamazaki, A.; Yoneda, M.; Yoshikawa, I.; Yoshioka, K.

    2016-02-01

    In January 2014 Jupiter's FUV main auroral oval decreased its emitted power by 70% and shifted equatorward by ˜1°. Intense, low-latitude features were also detected. The decrease in emitted power is attributed to a decrease in auroral current density rather than electron energy. This could be caused by a decrease in the source electron density, an order of magnitude increase in the source electron thermal energy, or a combination of these. Both can be explained either by expansion of the magnetosphere or by an increase in the inward transport of hot plasma through the middle magnetosphere and its interchange with cold flux tubes moving outward. In the latter case the hot plasma could have increased the electron temperature in the source region and produced the intense, low-latitude features, while the increased cold plasma transport rate produced the shift of the main oval.

  18. [Aurore, child martyr. Essay on violence done to children].

    PubMed

    Gaudreau, J

    1992-01-01

    This article draws on the sad story of Aurore Gagnon, a battered child raised in rural Québec and whose turmoil was dramatized on film. By elaborating on this symbol, the author is able to generate, at least in a systemic perspective, a number of issues and outlooks that go far beyond the generalities usually associated with this tale. For instance, there is ample evidence showing that the behaviour of Aurore's stepmother, aberrant as it may be, is largely caused by a set of environmental circumstances. Of course, today's social conditions hardly resemble those of the past. Yet, given the conjunctions of certain factors, children, who are nevertheless our most valuable asset, continue to be in danger in the presence of their very own parents.

  19. The chemical effects of auroral oxygen precipitation at Jupiter

    NASA Technical Reports Server (NTRS)

    Cravens, T. E.; Eisenhower, G. M.

    1992-01-01

    A numerical model of the auroral ionosphere and thermosphere of Jupiter, which includes odd oxygen species, is presented. Density profiles of neutral species O, OH, and H2O and the ion species H2(+), H3(+), H(+), H2O(+), H3O(+), O(+), and OH(+) are calculated. The total neutral odd oxygen density is found to be about 10 exp 5/cu cm near the auroral ionosphere peak. The major ionospheric ion, H(+) reacts rapidly with both O and H2O and the presence of these species in the model calculations significantly reduces the H(+) density and thus the electron density. The chemical lifetime against reaction of H(+) with odd oxygen is about 1000 s near the peak, whereas the radiative recombination lifetime is roughly 10,000 s.

  20. Electric field and plasma density measurements in the auroral electrojet

    NASA Astrophysics Data System (ADS)

    Pfaff, R. F.; Kelley, M. C.; Fejer, B. G.; Kudeki, E.; Carlson, C. W.; Pedersen, A.; Hausler, B.

    1984-01-01

    Extensive experimental and theoretical studies of auroral and equatorial electrojet irregularities have been conducted for the last two decades. The present investigation is concerned with electric field and plasma density fluctuation measurements made on board of the Porcupine II sounding rocket and on a free-flyer ejected from the main spacecraft. The Porcupine II sounding rocket payload was launched at 1922:00 UT from Kiruna, Sweden, on March 20, 1977. The considered results show electrostatic turbulence in the unstable auroral E region confined to a layer between 96 and 121 km. The similarities between the observations of two simultaneous payloads spaced a few kilometers apart indicate that on a large scale, the electrojet turbulence displays uniform characteristics.

  1. Stationary electrostatic solitary waves in the auroral plasma

    NASA Technical Reports Server (NTRS)

    Lotko, W.; Kennel, C. F.

    1981-01-01

    Time-stationary fluid equations are used to describe electrostatic solitons in an auroral plasma of cold ionospheric and hot plasma sheet particles. A one-dimensional fluid analysis of the four component model auroral plasma indicates that at least two different, weakly damped, small amplitude electrostatic solitons can propagate along the geomagnetic field. The slower of the two is a generalization of an ion-acoustic solitary wave in a multi-component plasma, and ion inertia is negligible for the faster mode which is supported by the two electron components and resembles a clump of shielded negative space charge convected by the drifting plasma sheet electrons. Some expected features of the large amplitude properties are indicated qualitatively, and an analogy is considered between the theory of ion-acoustic shocks and a theory of double layers.

  2. Inferences Concerning the Magnetospheric Source Region for Auroral Breakup

    NASA Technical Reports Server (NTRS)

    Lyons, L. R.

    1992-01-01

    It is argued that the magnetospheric source region for auroral arc breakup and substorm initiation is along boundary plasma sheet (BPS) magnetic field lines. This source region lies beyond a distinct central plasma sheet (CPS) region and sufficiently far from the Earth that energetic ion motion violates the guiding center approximation (i.e., is chaotic). The source region is not constrained to any particular range of distances from the Earth, and substorm initiation may be possible over a wide range of distances from near synchronous orbit to the distant tail. It is also argued that the layer of low-energy electrons and velocity dispersed ion beams observed at low altitudes on Aureol 3 is not a different region from the region of auroral arcs. Both comprise the BPS. The two regions occasionally appear distinct at low altitudes because of the effects of arc field-aligned potential drops on precipitating particles.

  3. Isis 1 observations at the source of auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Benson, R. F.; Calvert, W.

    1979-01-01

    Observations of auroral kilometric radiation (AKR) were made by Isis 1 in the source region. The radiation is found to be generated in the extraordinary mode just above the local cut-off frequency and to emanate nearly perpendicular to the magnetic field. It occurs within local depletions of electron density, where the ratio of plasma frequency to cyclotron frequency is less than 0.2. The density depletion is restricted to altitudes above about 2000 km, and the upper AKR frequency limit corresponds to the extraordinary cut-off frequency at this altitude. AKR is observed from Isis 1 above the nighttime auroral zone over a wider extent in longitude than in latitude with an intense source region observed most often near 2200 LMT and 70 deg invariant latitude. It is directly related to inverted V electron precipitation events with an electron-to-wave energy conversion efficiency of the order of 0.1 to 1%.

  4. Preliminary observations from the Auroral and Ionospheric Remote Sensing imager

    NASA Astrophysics Data System (ADS)

    Meng, Ching I.; Huffman, Robert E.

    1987-09-01

    The scientific objectives and the instrumentation of the Polar BEAR's Auroral and Ionospheric Remote Sensing (AIRS) experiment are described together with the techniques employed for global imaging and the results of preliminary observations. The AIRS four-color imager covers selected wavelengths in the visible/near UV and vacuum UV (VUV) ranges. The AIRS experiment also has advantages of narrow 3.0-nm VUV bandpath imaging, not possible with the use of interference filters, and of three alternative modes of operation (imaging, spectrometer, or photometer), possible by controlling the scan mirror and the spectrometer gridding motor. Because of the satellite's high altitude (about 1000 km), most of the auroral oval can be imaged.

  5. Recommended Program Activities, 1988-1998

    NASA Technical Reports Server (NTRS)

    1984-01-01

    The observations needed from the standpoint of measurement programs are considered and the technologies which must be developed and the flight missions which must be carried out to support ground-based measurements are discussed. Instrument development for millimeter accuracy in both the horizontal and vertical components as well as for sensitivity to short wavelengths is discussed. Algorithms and models in the application of space data in geodynamics demand special attention. Continued development of airborne and spaceborne laser ranging systems should be supported.

  6. Ionospheric Convection in the Postnoon Auroral Oval: SuperDARN and Polar UVI Observations

    NASA Technical Reports Server (NTRS)

    Kozlovsky, A.; Koustov, A.; Lyatsky, W.; Kangas, J.; Parks, G.; Chua, D.

    2002-01-01

    Super Dual Auroral Radar Network (SuperDARN) observations, ultraviolet imaging from the Polar satellite (UVI), and particle precipitation data from DMSP satellites have been used to investigate the electrodynamics of the postnoon auroral oval in the Northern hemisphere. We show that: (1) For negative IMF By, the convection reversal (CR) was co-located with the maximum of auroral luminosity, but during positive IMF By the convection reversal was poleward of the auroral oval up to several degrees in latitude; (2) Postnoon auroral oval was associated with a large-scale upward field-aligned current (FAC) of the order of 6x10(exp -7). A m(exp -2) in magnitude (the FAC was inferred from the SuperDARN and UVI data). For negative IMF By, maximum of the auroral intensity coincides in latitude with the maximum of the upward field-aligned current. However, for positive IMF By. the maximum of the upward FAC was shifted to the poleward edge of the auroral oval; (3) In response to the IMF By turning from positive to negative, the maximum of the auroral luminosity did not change its position noticeably, but the position of the convection reversal changed considerably from 80-81 degs to about 76 degs MLAT, and the maximum of FAC moved from 77-78 degs to about 76 degs MLAT. Thus, after IMF By turns negative, both the FAC maximum and CR tend to coincide with the auroral maximum; (4) The IMF Bz positive deflection was followed by a decrease in both field-aligned current intensity and auroral luminosity. However, the decrease in the auroral luminosity lags behind the FAC decrease by about 12 min. Firstly, these observations allow us to suggest that the IMF By-related electric field can penetrate into the closed magnetosphere and produce convection and FAC changes in the region of the postnoon auroral oval. Secondly, we suggest that the interchange instability is a promising mechanism for the postnoon auroras.

  7. Saturation and energy-conversion efficiency of auroral kilometric radiation

    NASA Technical Reports Server (NTRS)

    Wu, C. S.; Tsai, S. T.; Xu, M. J.; Shen, J. W.

    1981-01-01

    A quasi-linear theory is used to study the saturation level of the auroral kilometric radiation. The investigation is based on the assumption that the emission is due to a cyclotron maser instability as suggested by Wu and Lee and Lee et al. The thermodynamic bound on the radiation energy is also estimated separately. The energy-conversion efficiency of the radiation process is discussed. The results are consistent with observations.

  8. Io-related Jovian auroral arcs: Modeling parallel electric fields

    NASA Astrophysics Data System (ADS)

    Su, Yi-Jiun; Ergun, Robert E.; Bagenal, Fran; Delamere, Peter A.

    2003-02-01

    Recent observations of auroral arcs on Jupiter suggest that electrons are being accelerated downstream from Io's magnetic footprint, creating detectable emissions. The downstream electron acceleration is investigated using one-dimensional spatial, two-dimensional velocity static Vlasov solutions under the constraint of quasi-neutrality and an applied potential drop. The code determines self-consistent charged particle distributions and potential structure along a magnetic field flux tube in the upward (with respect to Jupiter) current region of Io's wake. The boundaries of the flux tube are the Io torus on one end and Jupiter's ionosphere on the other. The results indicate that localized electric potential drops tend to form at 1.5-2.5 RJ Jovicentric distance. A sufficiently high secondary electron density causes an auroral cavity to be produced similar to that on Earth. Interestingly, the model results suggest that the proton and the hot electron population in the Io torus control the electron current densities between the Io torus and Jupiter and thus may control the energy flux and the brightness of the aurora downstream from Io's magnetic footprint. The parallel electric fields also are expected to create an unstable horseshoe electron distribution inside the auroral cavity, which may lead to the shell electron cyclotron maser instability. Results from our model suggest that in spite of the differing boundary conditions and the large centrifugal potentials at Jupiter, the auroral cavity formation may be similar to that of the Earth and that parallel electric fields may be the source mechanism of Io-controlled decametric radio emissions.

  9. Plasma Heating and Flow in an Auroral Arc

    NASA Technical Reports Server (NTRS)

    Moore, T. E.; Chandler, M. O.; Pollock, C. J.; Reasoner, D. L.; Arnoldy, R. L.; Austin, B.; Kintner, P. M.; Bonnell, J.

    1996-01-01

    We report direct observations of the three-dimensional velocity distribution of selected topside ionospheric ion species in an auroral context between 500 and 550 km altitude. We find heating transverse to the local magnetic field in the core plasma, with significant heating of 0(+), He(+), and H(+), as well as tail heating events that occur independently of the core heating. The 0(+) velocity distribution departs from bi-Maxwellian, at one point exhibiting an apparent ring-like shape. However, these observations are shown to be aliased within the auroral arc by temporal variations that arc not well-resolved by the core plasma instrument. The dc electric field measurements reveal superthermal plasma drifts that are consistent with passage of the payload through a series of vortex structures or a larger scale circularly polarized hydromagnetic wave structure within the auroral arc. The dc electric field also shows that impulsive solitary structures, with a frequency spectrum in the ion cyclotron frequency range, occur in close correlation with the tail heating events. The drift and core heating observations lend support to the idea that core ion heating is driven at low altitudes by rapid convective motions imposed by the magnetosphere. Plasma wave emissions at ion frequencies and parallel heating of the low-energy electron plasma are observed in conjunction with this auroral form; however, the conditions are much more complex than those typically invoked in previous theoretical treatments of superthermal frictional heating. The observed ion heating within the arc clearly exceeds that expected from frictional heating for the light ion species H(+) and He(+), and the core distributions also contain hot transverse tails, indicating an anomalous transverse heat source.

  10. Diffuse Auroral Precipitation Caused by Wave-Particle Scattering (Invited)

    NASA Astrophysics Data System (ADS)

    Thorne, R. M.; Ni, B.; Bortnik, J.; Li, W.; Nishimura, Y.

    2013-12-01

    Diffuse auroral electron precipitation provides over 70% of ionizing energy input into the nightside upper atmosphere and is a major contribution to the global distribution of high latitude ionospheric conductivity. It is therefore important to understand the origin of the electron precipitation, since this controls the electro-dynamic coupling between the ionosphere and the magnetosphere. Intense electromagnetic whistler-mode chorus emissions and electrostatic cyclotron harmonic (ECH) waves are excited following the injection of plasma sheet electrons (100 eV - 30 keV) into the inner magnetosphere. Resonant scattering by either plasma wave can potentially cause electron precipitation into the atmosphere and subsequent diffuse auroral excitation. However, quantitative analyses of the rate of electron scattering have shown that a combination of both upper band (f > fce/2) and lower band (f < fce/2) chorus provides the dominant mechanism for nightside diffuse auroral precipitation on magnetic field lines mapping to L < 8 where the diffuse aurora is most intense, and that lower band chorus acts as the major contributor to the occurrence of the diffuse aurora on the dayside. It has also been demonstrated that pulsating aurora is cause by the modulation of lower band chorus in the wave source region deep in the magnetosphere. Since chorus emissions are now considered to be important for causing both the loss and local acceleration of high-energy (> 500 keV) radiation belt electrons, the global distribution of diffuse auroral precipitation measured either on the ground or by low altitude satellites can be used to infer the global intensity of chorus waves for subsequent radiation belt modeling.

  11. Electrostatic double layers as auroral particle accelerators - a problem

    NASA Astrophysics Data System (ADS)

    Bryant, D. A.; Courtier, G. M.

    2015-04-01

    A search of the Annales Geophysicae database shows that double layers and other quasi-static electric potential structures have been invoked hundreds of times since the year 2000 as being the agents of auroral electron acceleration. This is despite the fact that energy transfer by conservative fields has been known for some 200 years to be impossible. Attention is drawn to a long-standing interpretation of the acceleration process in terms of the dynamic fields of electrostatic waves.

  12. Particle simulation of auroral double layers. Doctoral thesis

    SciTech Connect

    Smith, B.L.

    1992-06-01

    Externally driven magnetic reconnection has been proposed as a possible mechanism for production of auroral electrons during magnetic substorms. Fluid simulations of magnetic reconnection lead to strong plasma flows towards the increasing magnetic field of the earth. These plasma flows must generate large scale potential drops to preserve global charge neutrality. We have examined currentless injection of plasma along a dipole magnetic field into a bounded region using both analytic techniques and particle simulation.

  13. Active microwave users working group program planning

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.; Bare, J.; Brown, W. E., Jr.; Childs, L. F.; Dellwig, L. F.; Heighway, J. E.; Joosten, R.; Lewis, A. J.; Linlor, W.; Lundien, J. R.

    1978-01-01

    A detailed programmatic and technical development plan for active microwave technology was examined in each of four user activities: (1) vegetation; (2) water resources and geologic applications, and (4) oceanographic applications. Major application areas were identified, and the impact of each application area in terms of social and economic gains were evaluated. The present state of knowledge of the applicability of active microwave remote sensing to each application area was summarized and its role relative to other remote sensing devices was examined. The analysis and data acquisition techniques needed to resolve the effects of interference factors were reviewed to establish an operational capability in each application area. Flow charts of accomplished and required activities in each application area that lead to operational capability were structured.

  14. 3D modelling of stellar auroral radio emission

    NASA Astrophysics Data System (ADS)

    Leto, P.; Trigilio, C.; Buemi, C. S.; Umana, G.; Ingallinera, A.; Cerrigone, L.

    2016-06-01

    The electron cyclotron maser is the coherent emission process that gives rise to the radio lighthouse effect observed in the hot magnetic chemically peculiar star CU Virginis. It has also been proposed to explain the highly circularly polarized radio pulses observed in some ultracool dwarfs with spectral type earlier than M7. Coherent events of this kind resemble auroral radio emission from the magnetized planets of the Solar system. In this article, we present a three-dimensional model able to simulate the timing and profile of the pulses emitted by those stars characterized by a dipolar magnetic field by following the hypothesis of the laminar source model, used to explain the beaming of terrestrial auroral kilometric radiation. This model proves to be a powerful tool with which to understand the auroral radio emission phenomenon, allowing us to derive some general conclusions about the effects of the model's free parameters on the features of coherent pulses and to learn more about the detectability of such pulsed radio emission.

  15. Direct measurements of severe spacecraft charging in auroral ionosphere

    NASA Technical Reports Server (NTRS)

    Burke, W. J.; Hardy, D. A.; Rich, F. J.; Rubin, A. G.; Tautz, M. F.; Saflekos, N. A.; Yeh, H. C.

    1985-01-01

    Questions are addressed concerning how large space structures in polar orbit will interact with auroral environments. Because spacecraft charging at ionospheric attitudes does not seriously threaten the operation of today's relatively small polar satellites the subject of environment interactions has not received the widespread attention given to it at geostationary altitude. As a matter of economics it is desirable to apply as much as possible of what was learned about spacecraft interactions at geostationary orbit to low Earth orbits. The environment at auroral latitudes in the ionosphere differs from that encountered at geostationary altitude in at least two major aspects. (1) There is a large reservoir of high-density, cold plasma which tends to mitigate charging effects by providing a large source of charged particles from which neutralizing currents maybe drawn. Significant wake effects behind large structures will introduce new problems with differential charging. (2) Between the magnetic equator and the ionosphere, auroral electrons frequently undergo field-aligned accelerations of several kilovolts. In such environments, fluxes of energetic protons are usually below the levels of instrumentation sensitivity.

  16. The night when the auroral and equatorial ionospheres converged

    NASA Astrophysics Data System (ADS)

    Martinis, C.; Baumgardner, J.; Mendillo, M.; Wroten, J.; Coster, A.; Paxton, L.

    2015-09-01

    An all-sky imaging system at the McDonald Observatory (30.67°N, 104.02°W, 40° magnetic latitude) showed dramatic ionospheric effects during a moderate geomagnetic storm on 1 June 2013. The auroral zone expanded, leading to the observation of a stable auroral red (SAR) arc. Airglow depletions associated with equatorial spread F (ESF) were also seen for the first time at such high magnetic latitude. Total electron content measurements from a Global Positioning System (GPS) receiver exhibited ionospheric irregularities typically associated with ESF. We explore why this moderate geomagnetic disturbance leads to such dramatic ionospheric perturbations at midlatitudes. A corotating interaction region-like driver and a highly contracted plasmasphere caused the SAR arc to occur at L shell ~ 2.3. For ESF at L ~ 2.1, timing of the storm intensification, alignment of the sunset terminator with the central magnetic meridian, and sudden variations in the westward auroral electrojet all combined to trigger equatorial irregularities that reached altitudes of ~ 7000 km. The SAR arc and ESF signatures at the ionospheric foot points of inner magnetosphere L shells (L ~ 2) represent a dramatic convergence of pole to equator/equator to pole coupling at midlatitudes.

  17. Instrument for the monochromatic observation of all sky auroral images.

    PubMed

    Mende, S B; Eather, R H; Aamodt, E K

    1977-06-01

    To investigate the dynamics of auroras and faint upper atmospheric emissions, a new type of imaging instrument was developed. The instrument is a wide field of view, narrow-spectral-band imaging system using an intensified S.E.C. TV camera in a time exposure mode. Pictures were taken at very low light levels of a few photons per exposure per resolution element. These pictures are displayed in the form of a pseudocolor presentation in which the color represents spectral ratios of two of the observed auroral spectral emission features. The spectral ratios play an important part in the interpretation of auroral particle dynamics. A digital picture processing facility is also part of the system which enables the digital manppulation of the pictures at standard TV rates. As an example, hydrogen auroras can be displayed having been corrected for nonspectral background by subtracting a picture obtained by a suitable background filter. The instrumentation was calibrated in the laboratory and was used in several field xperiments. Elaborate exposure sequences were developed to extend the dynamic range and to cover the large range of auroral brightnesses in a fairly linear manner. PMID:20168774

  18. Inferences concerning the magnetospheric source region for auroral breakup

    NASA Technical Reports Server (NTRS)

    Lyons, L. R.

    1992-01-01

    Inferences concerning the magnetospheric source region for auroral arcs obtained from particle measurements on polar orbiting satellites are presented and contrasted with other ideas. An argument that the magnetospheric source region for auroral arc breakup and substorm initiation is along Boundary Plasma Sheet (BPS) magnetic field lines is given. This source region lies beyond a distinct central plasma sheet region and sufficiently far from the Earth that energetic ion motion violates the guiding center approximation (is chaotic). The source region is not constrained to any particular range of distances from the Earth, and substorm initiation may be possible over a wide range of distances from near synchronous orbit to the distant tail. It is also argued that the layer of low energy electrons and velocity dispersed ion beams observed at low altitudes on Aureol 3 is not a different region from the region of auroral arcs. Both comprise the BPS. The two regions occasionally appear distinct at low altitudes because of the effects of arc field aligned potential drops on precipitating particles.

  19. Instrument for the monochromatic observation of all sky auroral images.

    PubMed

    Mende, S B; Eather, R H; Aamodt, E K

    1977-06-01

    To investigate the dynamics of auroras and faint upper atmospheric emissions, a new type of imaging instrument was developed. The instrument is a wide field of view, narrow-spectral-band imaging system using an intensified S.E.C. TV camera in a time exposure mode. Pictures were taken at very low light levels of a few photons per exposure per resolution element. These pictures are displayed in the form of a pseudocolor presentation in which the color represents spectral ratios of two of the observed auroral spectral emission features. The spectral ratios play an important part in the interpretation of auroral particle dynamics. A digital picture processing facility is also part of the system which enables the digital manppulation of the pictures at standard TV rates. As an example, hydrogen auroras can be displayed having been corrected for nonspectral background by subtracting a picture obtained by a suitable background filter. The instrumentation was calibrated in the laboratory and was used in several field xperiments. Elaborate exposure sequences were developed to extend the dynamic range and to cover the large range of auroral brightnesses in a fairly linear manner.

  20. Features of the processes of ion heating in polar boundary of the night auroral oval

    NASA Astrophysics Data System (ADS)

    Chugunin, Dmitriy; Lutsenko, Volt; Romantsova, Tatiana; Mogilevsky, Mikhail; Moiseenko, Irina

    Investigation of the processes of ion heating in polar boundary of the night auroral oval measured by INTERBALL-2 (Auroral probe) is presented. Measurements of particles and waves were made on altitude about 20000 км. Feature of the orbits was the satellite slid along auroral oval and stay long time in the auroral zone. It were cases chosen when the polar boundary moved and passed through satellite. Particular attention is given to ions heating at this border and to ion heating position in relation to polar boundary of particle precipitation.

  1. Effects of an Individualized Activity Program on Elderly Patients

    ERIC Educational Resources Information Center

    Salter, Carlota de Lerma; Salter, Charles A.

    1975-01-01

    A combined program of Reality Orientation, Activities of Daily Living, and Recreational Activities, together with environmental stimulation, was applied on an individualized basis to 21 elderly patients suffering from both psychological disorders and long-term physical illness. The motivation to participate in the available activities increased…

  2. Activity Based Astronomy for Primary Science Programs.

    ERIC Educational Resources Information Center

    Ginns, Ian

    Print materials in astronomy such as books, journals, charts, and posters are typically the sources of information for teachers and children about the moon, the sun, lunar and solar eclipses, planetary sizes, distances of planets from the sun, planetary atmospheres, and so on. This paper describes and analyzes a number of activities designed to…

  3. 29 CFR 36.400 - Education programs or activities.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or... these Title IX regulations, no person shall, on the basis of sex, be excluded from participation in,...

  4. 29 CFR 36.400 - Education programs or activities.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or... these Title IX regulations, no person shall, on the basis of sex, be excluded from participation in,...

  5. 29 CFR 36.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Labor Office of the Secretary of Labor NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or... these Title IX regulations, no person shall, on the basis of sex, be excluded from participation in,...

  6. Implications for Comprehensive School Physical Activity Program Implementation

    ERIC Educational Resources Information Center

    Karp, Grace Goc; Scruggs, Philip W.; Brown, Helen; Kelder, Steven H.

    2014-01-01

    As mentioned in the introduction, Physical Education Teacher Education (PETE) programs and physical education teachers will need to identify and resolve the tensions of shifting from a traditional role of a self-contained physical education program to that of an expanding role of physical education that supports lifelong physical activity in…

  7. 44 CFR 19.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY GENERAL NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or... these Title IX regulations, no person shall, on the basis of sex, be excluded from participation in,...

  8. 10 CFR 5.400 - Education programs or activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Energy NUCLEAR REGULATORY COMMISSION NONDISCRIMINATION ON THE BASIS OF SEX IN EDUCATION PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE Discrimination on the Basis of Sex in Education Programs or... these Title IX regulations, no person shall, on the basis of sex, be excluded from participation in,...

  9. University Student Participation and Perception of Intramural Program Activities.

    ERIC Educational Resources Information Center

    Zuercher, Suzanne; And Others

    A sample of 286 University of Maryland, College Park, undergraduates were surveyed on their participation in and their perception of the intramural sports program and related activities of the institution. Ninety-three percent of those surveyed was aware of the intramural program and 43 percent indicated that they participated (70 percent male, 30…

  10. Modulation of macrophage activation and programming in immunity.

    PubMed

    Liu, Guangwei; Yang, Hui

    2013-03-01

    Macrophages are central mediators of the immune, contributing both to the initiation and the resolution of inflammation. The concept of macrophage activation and program has stimulated interest in its definition, and functional significance in homeostasis and diseases. It has been known that macrophages could be differently activated and programmed into different functional subtypes in response to different types of antigen stumuli or different kinds of cytokines present in the microenvironment and could thus profoundly influence immune responses, but little is known about the state and exact regulatory mechanism of macrophage activation and program from cell or molecular signaling level in immunity. In this review, we summarize the recent finding regarding the regulatory mechanism of macrophage activation and program toward M1 and M2, especially on M2 macrophages.

  11. Repository Technology Program activities, FY 1988

    SciTech Connect

    Yow, J.L. Jr.; Wijesinghe, A.M.; Thorpe, R.K.; Knapp, R.B.

    1989-07-01

    Our technical activities in FY 1988 included instrument selection and evaluation, calculational work, and simulator development. Near the end of the fiscal year, we began preparing several topical reports to document our results. This fiscal year, we continued developing three-dimensional numerical simulators to model coupled hydrologic-and mechanical-rock mass responses and, thus, to provide representative numerical tools for understanding and calculating these in situ processes. We also began scoping calculations in the second half of FY 1988 to evaluate ERE design criteria, but this work was redirected late in the year when the DOE/AECL Subsidiary Agreement was set aside. Our work in developing and evaluating experimental techniques focused on total pressure measurements, moisture content measurement, and tracer detection instrumentation for sealing experiments and for rock-mass-response field tests. At the end of the fiscal year, we completed a review of measurement technology for instrumenting migration/sorption tests to help define the technological requirements in these areas. By the end of FY 1988, we had completed a review of the existing codes for simulating reactive transport; we are using the results of this review to help formulate plans for future activities in this area. The following sections describe the major RTP tasks and activities at LLNL in more detail, and they include our FY 1988 accomplishments in these areas. 8 refs., 22 figs.

  12. The Evolution of North-South Aligned Auroral Forms into Auroral Torch Structures : The Generation of Omega Bands and Ps6 Pulsations via Flow Bursts.

    SciTech Connect

    Henderson, M. G.; Kepko, L.; Spence, H. E.; Connors, M.; Sigwarth, J. B.; Frank, L. A.; Singer, H. J.; Yumoto, K.

    2002-01-01

    Although auroral torch structures and omega bands have been observed and studied for decades, a satisfactory understanding of how they form has yet to be achieved. Using global auroral imager data, we show conclusively that the equatorward moving north-south (NS) aligned auroral forms that are ejected episodically from the poleward boundary can evolve directly into torch structures which contribute to a well-defined omega-band form. And that as a consequence, omega bands can be produced as a direct result of earthward-directed bursty bulk flows (BBFs).

  13. Comparison between the polar cap index, PC and the auroral electrojet indices AE, AL, and AU

    SciTech Connect

    Vennerstrom, S.; Friis-Christensen, E. ); Troshichev, O.A.; Andresen, V.G. )

    1991-01-01

    The newly introduced index PC for magnetic activity in the polar cap has been examined to establish to which extent it can serve as an indicator of auroral electrojet activity. PC is derived from a single nearpole station, as a 15-min average index. The authors have derived it for two stations, one in the northern hemisphere (Thule) and one in the southern hemisphere (Vostok). The simplicity of the PC index enables us to make a large data base for statistical investigations. They have thus used 7 years of PC values for the two stations to analyze the relationship between PC and the auroral zone indices AE, AU, and AL statistically. They find a very high correlation between PC and AE during winter and equinox, the linear correlation coefficient being {approximately} 0.8-0.9 for Thule and {approximately} 0.7-0.8 for Vostok. During summer the correlation is less because the PC index is then disturbed by polar cap currents controlled by the northward and east-west components of the interplanetary magnetic field. They therefore stress the importance of having PC available from both the northern and southern hemisphere. From event studies they find that PC is sensitive both to DP 2 type electrojet activity and to substorm intensifications of the westward electrojet in the midnight or postmidnight sector but less sensitive to substorm intensifications of the westward electrojet in the midnight or post midnight sector. They conclude that PC can serve as a fast available indicator of DP 2 and DP 1 activity in the polar regions, excluding intrusions of the westward electrojet in the premidnight sector.

  14. [Afterschool physical activity programs: Literature review].

    PubMed

    Reloba-Martínez, Sergio; Martín-Tamayo, Ignacio; Martínez-López, Emilio José; Guerrero-Almeida, Laura

    2015-01-01

    The purpose of this review was to analyze the scientific production about extra-curricular physical activity (PA) in western children of 6-12 years. Medline / Pub-Med, Scopus and Google Scholar were used. This search collects articles published between January 1990 and May 2013. A total of 104 publications were analyzed. The body composition parameters are best used to assess the results of the studies, followed by those which estimate the maximum aerobic capacity. Articles of intervention are presented with very heterogeneous methodological features but there are clear trends in the use of certain aspects. As for the reviews, most are systematic and include meta-analysis. In this studies, body mass index (BMI) is the most used parameter.

  15. The Active Magnetospheric Particle Tracer Explorers program

    NASA Technical Reports Server (NTRS)

    Krimigis, S. M.; Mcentire, R. W.; Haerendel, G.; Paschmann, G.; Bryant, D. A.

    1983-01-01

    In order to study the access of solar wind ions to the magnetosphere, together with the processes that transport and accelerate magnetospheric particles, the Active Magnetospheric Particle Tracer Explorers (AMPTE) mission will release and monitor lithium and barium tracer ions in both the solar wind and the magnetosphere. A single, massive release of barium in the dawn magnetosheath will in addition create a visible artificial comet in the flowing solar wind plasma, within which studies of a range of different plasma effects will be undertaken. The AMPTE will obtain comprehensive measurements of natural magnetospheric particle populations' elemental composition and dynamics. AMPTE comprises three spacecraft: the Ion Release Module, the Charge Composition Explorer, and the United Kingdom Subsatellite.

  16. [Afterschool physical activity programs: Literature review].

    PubMed

    Reloba-Martínez, Sergio; Martín-Tamayo, Ignacio; Martínez-López, Emilio José; Guerrero-Almeida, Laura

    2015-01-01

    The purpose of this review was to analyze the scientific production about extra-curricular physical activity (PA) in western children of 6-12 years. Medline / Pub-Med, Scopus and Google Scholar were used. This search collects articles published between January 1990 and May 2013. A total of 104 publications were analyzed. The body composition parameters are best used to assess the results of the studies, followed by those which estimate the maximum aerobic capacity. Articles of intervention are presented with very heterogeneous methodological features but there are clear trends in the use of certain aspects. As for the reviews, most are systematic and include meta-analysis. In this studies, body mass index (BMI) is the most used parameter. PMID:26679320

  17. Aircraft: United States Air Force Child Care Program Activity Guide.

    ERIC Educational Resources Information Center

    Boggs, Juanita; Brant, Linda

    General information about United States' aircraft is provided in this program activity guide for teachers and caregivers in Air Force preschools and day care centers. The guide includes basic information for teachers and caregivers, basic understandings, suggested teaching methods and group activities, vocabulary, ideas for interest centers, and…

  18. Initiating and Strengthening College and University Instructional Physical Activity Programs

    ERIC Educational Resources Information Center

    Sweeney, Michelle M.

    2011-01-01

    The National Association for Sport and Physical Education supports the offering of strong college and university instructional physical activity programs (C/UIPAPs). With a rapid decline in physical activity levels, high stress levels, and unhealthy weight-loss practices among college-age students, it is apparent that C/UIPAPs embedded in the…

  19. Florida Migratory Child Compensatory Program Announcement of Staff Development Activities.

    ERIC Educational Resources Information Center

    Florida Atlantic Univ., Boca Raton.

    The intent given for the Florida Migratory Child Compensatory Program staff development activities is to assist local individual teachers, teacher groups, schools, and school districts in the implementation of in-service training activities that will enhance improvement of the individual teacher. Twenty-five experiences provided by…

  20. FAST/Polar Conjunction Study of Field-Aligned Auroral Acceleration and Corresponding Magnetotail Drivers

    NASA Technical Reports Server (NTRS)

    Schriver, D.; Ashour-Abdalla, M.; Strangeway, R. J.; Richard, R. L.; Klezting, C.; Dotan, Y.; Wygant, J.

    2002-01-01

    The discrete aurora results when energized electrons bombard the Earth's atmosphere at high latitudes. This paper examines the physical processes that can cause field-aligned acceleration of plasma particles in the auroral region. A data and theoretical study has been carried out to examine the acceleration mechanisms that operate in the auroral zone and to identity the magnetospheric drivers of these acceleration mechanisms. The observations used in the study were collected by the Fast Auroral SnapshoT (FAST) and Polar satellites when the two satellites were in approximate magnetic conjunction in the auroral region. During these events FAST was in the middle of the auroral zone and Polar was above the auroral zone in the near-Earth plasma sheet. Polar data was used to determine the conditions in the magnetotail at the time field-aligned acceleration was measured by FAST in the auroral zone. For each of the magnetotail drivers identified in the data study, the physics of field-aligned acceleration in the auroral region was examined using existing theoretical efforts and a long-system particle-in-cell simulation to model the magnetically connected region between the two satellites.