ELF Data Research Articles

Expanding the English as an International Language paradigm from different native language perspectives

Abstract The present paper aims at expanding the English as an International Language (EIL) paradigm and providing new insights into the current status and role of EIL.1 The main focus of the study is on information structuring (IS) in dialogic speech events to show how IS affects the use of particular constructions, namely it-clefts, wh-cleft and topicalisation (left dislocation) which seem to show higher frequency in EIL than in standard English (Biber et al. 1998). For the purpose of this preliminary study, samples of spoken ELF data including private dialogues and academic discussions were selected from the VOICE (Vienna-Oxford International Corpus of English) to investigate left-right asymmetries in EIL interactions, which is an area still lacking of attention with respect to lexical and other phrasal phenomena.

Resolving Elve, Halo and Sprite Halo Images at 10,000 Fps in the Taiwan 2020 Campaign

After almost thirty years’ efforts on studying transient luminous events (TLEs), ground-based observation has confirmed the TLE family, including elves, halos, sprites, and blue jets, etc. The typical elve has the shortest emission time (<1 ms) in comparison with other TLEs. The second shortest is the halo emission. Although elves and halos are supposed to be more frequent than sprites, ground campaigns still have less probability of recording their images due to their fleeting and short emission. Additionally, the submillisecond imaging of elves, halos, and sprite halos helps us resolve their electro-optic dynamics and morphological features, but few have been reported in the literature. Our study presents the 10,000 fps imaging frames on elves, halos and sprite halos, compares their similarity and disparity, and analyzes their parent lightning properties with associated VLF and ELF data.

Automatic display of ELF measurements recorded in the Széchenyi István Geophysical Observatory

From July 2020, ELF data recorded in the Széchenyi István Geophysical Observatory (SZIGO, IAGA code: NCK) near Nagycenk, Hungary is automatically displayed on the website of the observatory (http://nckobs.hu/data/sr/). The automatically generated figures contain the dynamic spectra of the HNS, HEW and EZ field components as well as the amplitude and frequency of the first three Schumann resonance (SR) modes as extracted by the complex demodulation algorithm from the EZ record. This important achievement allows us to continuously monitor the actual state of the measurements. Currently, the figure corresponding to the actual day is accessible for the public while the archive of figures is available only for the staff of the research institute. The number of people visiting the website is continuously tracked and the statistics confirm that there is considerable public interest in our measurements.

Parties, persons, and one-at-a-time: conversation analysis and ELF

AbstractDrawing on an analysis of ELF data, this article deals with the characteristics and complexities of turn-taking in interactions involving three or more participants. Sacks et al.’s (1974) often quoted framework for turn-taking in conversations, which can still be regarded canonical reading in the conversation analytic literature, serves as a starting point for this investigation. The aim of this paper is to scrutinize the applicability of the turn-taking model for group interactions. A key concept in this regard is the notion of aparty: the conversation analytic model for turn-taking posits that turn-taking does not take place between individual speakers, but between parties (hence the termmulti-party conversation) which can potentially consist of several speakers (cf. Schegloff 1995: 32–33). In group interactions it is thus possible that overlap occurs among co-incumbents of the same party. This kind of simultaneous speech, however, has not yet been subject of systematic empirical analysis. The present paper offers a preliminary account of this aspect of turn-taking in multi-participant interaction by discussing data extracts from an ELF workplace meeting of seven speakers and suggests possible avenues for further research on the phenomenon.

A corpus-driven analysis of repair in a professional ELF meeting: Not ‘letting it pass’

The current study examines turn-taking in a multiparty professional ELF meeting from a bridge-building project in South Asia, using a corpus-assisted discourse analysis. The results show that two of the 15 participants, the Chair and the design consultant, spoke most in the meeting. The Chair took relatively shorter speaker turns, for instance cutting in the conversation and giving corrections or suggestions. We term this discursive practice ‘not let it pass’, in contrast to Firth's (1996) concept of ‘let it pass’, a widely used practice in his business ELF data and other business ELF research. The occurrences of ‘not let it pass’, encompassing other-repair and other-reformulation, practices are analysed in relation to the unfolding discourse, the participants’ goals, and the dynamics of their inter/intra-group relationships. Repair interactions are often observed between members of different institutional groups and nationalities, whereas reformulation interactions were mainly initiated by the Chair with intra-group members. From retrospective interviews, it was clear that a core motivation for the Chair's use of such discursive practices was the comprehension of the audience, rather than the inherent markedness of the message itself. Furthermore, repair fulfils transactional and interpersonal goals, but was not directed at problems of acceptability.

“I just wanted to give a partly answer”: capturing and exploring word class variation in ELF data

Abstract English as a lingua franca is generally viewed as a user language in which the formal characteristics are adapted to meet the communicative needs of its speakers, inherently resulting in linguistic innovation and variation. In the part-of-speech (POS) tagging of the Vienna-Oxford International Corpus of English (VOICE), many cases were encountered whereby ELF users go beyond the commonly assumed boundaries of word class categories in Standard English by the process defined as word class change. Word class change is understood as a change of word class category, or syntagmatic function, without alternation of the morphological form. In this paper, it is demonstrated how forms which were used in a non-codified function were dealt with in the tagging procedure. Reviewing concepts commonly used to explain word class change, namely conversion and multifunctionality, it is argued that a number of presumptions inherent in these concepts cause difficulties when applied to ELF data. In a case study, the most frequent types of word class shifts or variation (terms which are considered more suitable for ELF data) in VOICE are exemplified, analysed, and discussed with regard to the forms which are shifted, the directionality of these shifts, as well as the environment in which the shifts occur. It is shown that word class shifts in ELF interactions follow clear tendencies and thus a reconceptualization of the concepts of conversion and multifunctionality with regard to ELF is proposed. Finally, it is argued that if tagging practices attempt to display, rather than disguise, initial “problems” arising in the tagging process, this can help to gain useful insights into the nature of the data.

New color images of transient luminous events from dedicated observations on the International Space Station

During July–August 2011, Expedition 28/29 JAXA astronaut Satoshi Furukawa conducted TLE observations from the International Space Station in conjunction with the “Cosmic Shore” program produced by NHK. An EMCCD normal video-rate color TV camera was used to conduct directed observations from the Earth-pointing Cupola module. The target selection was based on the methodology developed for the MEIDEX sprite campaign on board the space shuttle Columbia in January 2003 (Ziv et al., 2004). The observation geometry was pre-determined and uploaded daily to the ISS with pointing options to limb, oblique or nadir, based on the predicted location of the storm with regards to the ISS. The pointing angle was rotated in real-time according to visual eyesight by the astronaut. We present results of 10 confirmed TLEs: 8 sprites, 1 sprite halo and 1 gigantic jet, out of <2h of video. Sprites tend to appear in a single frame simultaneously with maximum lightning brightness. Unique images (a) from nadir of a sprite horizontally displaced form the lightning light and (b) from the oblique view of a sprite halo, enable the calculation of dimensions and volumes occupied by these TLEs. Since time stamping on the ISS images was accurate within 1s, matching with ELF and WWLLN data for the parent lightning location is limited. Nevertheless, the results prove that the ISS is an ideal platform for lightning and TLE observations, and careful operational procedures greatly enhance the value of observation time.

ELF/VLF recordings during the 11 March 2011 Japanese Tohoku earthquake

Broadband ELF/VLF radio recordings (0.2–40 kHz) were made at a site in Onagawa, Japan located ∼102 km from the epicenter of the M9.0 11 March 2011 earthquake, the fifth most powerful earthquake in recorded history. The receiver operated for about two minutes after the start of the earthquake, after which the receiver lost power. Examination of the VLF data shows no radio emissions preceding or coincident with the onset of the earthquake. However, once the secondary seismic waves reached the receiver, a number of impulses and diffuse noise bands arose which may result from the entire power grid shaking or from radio emissions from compressing rocks. Examination of the ELF data (0.2–1 kHz) show no precursor effect in the hours preceding the earthquake. Examination of VLF data from narrowband transmitters shows no anomalous activity in the days or weeks preceding the earthquake. Our instrument low‐frequency cut‐off is ∼200 Hz, and thus we cannot comment on emissions in the ULF range (&lt;10 Hz).

Satellite observations of Schumann resonances in the Earth's ionosphere

[1] Using electric field measurements gathered on the C/NOFS satellite, we report, Schumann resonance signatures detected in space, well beyond the upper boundary of the resonant cavity formed by the earth's surface and the lower edge of the ionosphere. The resonances are routinely observed in the satellite ELF data during nighttime conditions within the altitude region of 400–850 km sampled by the satellite. They exhibit the distinctive frequency patterns predicted for Schumann resonances and are consistent with the corresponding frequency characteristics of ground-based observations of this phenomenon. The observations of Schumann resonances in space support a leaky cavity interpretation of the ionosphere and call for revisions of models of extremely low frequency wave propagation in the ionosphere. They suggest new remote sensing capabilities for investigating atmospheric electricity on Earth and other planets.

Gigantic jets produced by an isolated tropical thunderstorm near Réunion Island

Five gigantic jets (GJs) have been recorded with video and photograph cameras on 7 March 2010 above an isolated tropical storm east of Reunion Island. Three of them were produced before the storm reached its coldest cloud top temperature (approximately −81°C), and two others occurred during the cloud extension. Thanks to the close distance of observation (∼50 km), the luminosity within the cloud was recorded, and the events are analyzed in unprecedented detail. The tops of the GJs are estimated between 80 and 90 km. All these GJs are accompanied by long, continuous cloud illumination, and they are preceded and followed by intermittent optical flashes from the cloud, most of time without any cloud-to-ground (CG) flash simultaneously detected, which suggests they originated mainly as intracloud discharges and without any charge transfer to Earth. The CG lightning activity is observed to cease a few tens of seconds before the jets. According to ELF data recorded at Nagycenk, Hungary, the five GJs serve to raise negative charge. Their duration ranges from 333 to 850 ms. The leading jet has the most variable duration (33-167 ms) and propagates faster at higher altitudes. The trailing jet exhibits a continuous decrease of luminosity in different parts of the jet (lower channel, transition zone and, for most events, carrot sprite-like top) and in the cloud, with possible rebrightening. The lower channels (∼20-40 km altitude) produce blue luminosity which decreases with altitude and become more and more diffuse with time. The transition zone (around 40-65 km) consists of bright red, luminous beads slowly going up (∼104 m s−1), retracing the initial leading jet channels.

Cloud-to-ground lightning dipole moment from simultaneous observations by ELF receiver and combined direction finding and time-of-arrival lightning detection system

[1] We present a new method of automatic detection of ELF impulses related to cloud-to-ground lightning at distances 1–2 Mm from a broadband ELF receiver and also we present a new numerical automated technique for calculating the lightning dipole moment. We have performed the detection for two known data sets of lightning flashes detected by the French lightning detection network Meteorage in southwest Europe over two 48 h periods 28–29 July and 6–7 September 2005. The number of flashes identified in the ELF data compared to the number of flashes detected by Meteorage reach 10–25% when little local activity close to the ELF station is present. The local thunderstorm activity worsens the detection of lightning from larger distances and the efficiency of identification of ELF impulses as lightning can decrease to a few percent. By combining the information on the location of the lightning flashes from Meteorage with the ELF data, lightning dipole moments can be calculated. Our results suggest the dipole moment is linearly correlated with the lightning peak current (p ≃ 7.5 Imax) but the dispersion of the dipole moment for a given peak current is significant. One of the reasons of such dispersion is the contribution of the lightning continuing current to the ELF signal.

Absolute optical energy of sprites and its relationship to charge moment of parent lightning discharge based on measurement by ISUAL/AP

Although the Quasi‐electrostatic (QE) model has been considered a basic mechanism for describing sprite generation, the relationship between sprite luminosity and the charge moment change (CMC) value, caused by the sprites' parent lightning has not been examined quantitatively. CMC value represents the energy of cloud‐to‐ground discharge (CG) and the electric field intensity above the thunderstorm. We focused on the data obtained in 2004, in which both ISUAL on board the FORMOSAT‐2 satellite and the Tohoku ELF network were operated throughout one year. We could estimate the absolute luminous intensity of sprites free from atmospheric influence with the ISUAL/Array Photometer (AP) and investigated its relationship to the charge moment of parent lightning. Absolute optical energies emitted from sprites were estimated for 14 streamer‐type sprites for the first time. The averages of the time‐integrated optical energies are 176 kJ and 119 kJ for the N2 1PG and N2 2PG bands, respectively. Furthermore, the optical energies and the charge moments of their parent lightning estimated with ELF data show a high correlation (correlation coefficient = 0.93), that is consistent, qualitatively, with the QE model. This relationship predicts that the 50% occurrence probability is located at ∼600 C km, which coincides with previous statistical studies.

ELF and VLF signatures of sprites registered onboard the low altitude satellite DEMETER

Abstract. We report the observation of ELF and VLF signature of sprites recorded on the low altitude satellite DEMETER during thunderstorm activity. At an altitude of ~700 km, waves observed on the E-field spectrograms at mid-to-low latitudes during night time are mainly dominated by up-going 0+ whistlers. During the night of 20 July 2007 two sprites have been observed around 20:10:08 UT from the observatory located on the top of the mountain Śnieżka in Poland (50°44'09" N, 15°44'21" E, 1603 m) and, ELF and VLF data have been recorded by the satellite at about 1200 km from the region of thunderstorm activity. During this event, the DEMETER instruments were switched in the burst mode and it was possible to register the wave forms. It is shown that the two sprites have been triggered by two intense +CG lightning strokes (100 kA) occurring during the same millisecond but not at the same location. Despite the distance DEMETER has recorded at the same time intense and unusual ELF and VLF emissions. It is shown that the whistler wave propagates from the thunderstorm regions in the Earth-ionosphere guide and enters in the ionosphere below the satellite. They last several tens of milliseconds and the intensity of the ELF waveform is close to 1 mV/m. A particularly intense proton whistler is also associated with these emissions.

Global distribution and characteristics of intense lightning discharges as deduced from ELF transients observed at Moshiri (Japan)

The ELF data during one year (July 15 – September 27, 2004 and October 1, 2005 to June 30) at a single station of Moshiri (Japan) are used to investigate the global distribution and characteristics of intense lightning discharges. The statistics of those ELF transients whose locations are sufficiently accurately determined, has yielded the following; (1) Enhanced activity is found in Asia (for both polarities), and small charge moment change (Qds) events are dominant in Asia, (2) Large Qds (≥500C·km) is dominant in Africa and America, with Qds >1000C•km being predominant in Africa. (3) Continents are rich in +CGs, while –CGs are dominant in the maritime Asia, and (4) The UT (universal time) dependence of occurrence rate of intense ELF transients is found to be completely in opposite phase to that of conventional worldwide thunderstorm activity, being concentrated in the UT interval from 20 h to 5 h.

Electron Structure of Iron Chalcogenide Clusters {Fe3Q} from AIM and ELF Data: Effect of Hydrogen Atoms on Interatomic Interactions

The electronic structure of [Fe(3)(micro(3)-Q)(CO)(9)](2-) and [(micro-H)(2)Fe(3)(micro(3)-Q)(CO)(9)] (Q = S, Se, and Te) complexes is studied with topological methods AIM and ELF. Fe-Fe bonds in [(micro-H)(2)Fe(3)(micro(3)-Q)(CO)(9)] complexes are shown to break down in the presence of H atoms.

Optical observations of transient luminous events associated with winter thunderstorms near the coast of Israel

We report the results of two observation campaigns conducted during the Northern Hemisphere winters of 2005–6 and 2006–7 aiming to detect transient luminous events (TLEs) above winter thunderstorms in the vicinity of Israel and the eastern coastline of the Mediterranean Sea. In 10 out of 31 different observation nights we detected 66 events: 56 sprites and 10 Elves. The detection ranges varied from 250 to 450 km. Sprites were found to be produced by active cells with a vertical dimension of 5–9 km and cloud top temperature ~ − 40 °C, embedded in a much larger matrix of stratiform precipitating cloudiness. This configuration closely resembles the conditions for winter sprites in the Hokuriku region of Japan. Synchronized with the optical observations, ELF data were recorded at two observation stations in Israel and Hungary in order to qualify and quantify parameters of the parent lightning discharge associated with the TLEs. These stations are located 500 km and 2100 km respectively from the Eastern Mediterranean Sea, where most TLEs occur. Among the optically observed TLE events, we found that all the ELF signals were produced solely by positive cloud-to-ground flashes (+ CGs), most of which were recorded in Israel (88%) and Hungary (77%). Calculation of the Charge Moment Change showed average values of 1400 ± 600 C km, with some extreme events exceeding 3500 C km. The average time delay between the ELF transient of the parent + CG and the observed sprites was 55 ms, with shorter delays for column sprites (42 ± 34 ms) compared to carrot sprites (68 ± 34). Furthermore, based on the ELF data, there were no early identifiable precursors to TLE occurrence in the regional lightning activity. From the spatial formation of the observed columniform sprites, we propose that columniform sprites are sometimes arranged in a 3-dimensional circular pattern, thus mapping the instantaneous electric field in the mesosphere.

Strained bonds in [Re4Q4X12]4− cluster complexes (Q = S, Se, Te; X = F, CN−) according to AIM and ELF data

The electron density distribution in [Re4Q4X12]4− cubane-like clusters (Q = S, Se, Te; X = F, CN) was investigated by the AIM and ELF topological quantum-chemical methods. The Re-Re, Re-Q, and Re-X interatomic interactions are characterized by bcp type critical binding points and are strained.

Characteristics of Japanese winter sprites and their parent lightning as estimated by VHF lightning and ELF transients

Sprites are newly discovered optical emissions in the mesosphere over large thunderstorms. This paper is the observational summary of winter sprites in the Hokuriku area of Japan and their parent lightning in the winter of 2004/2005, by using the coordinated optical and electromagnetic (VHF and ELF) measurements in Japan. As the results of optical observations at two stations, we have found that this campaign has yielded a variety of sprite shapes; V-angle shaped structures have been often observed (25%) in addition to columnar structures familiar for us. All of the sprite events are found to be associated with + CG lightning, as seen from the macroscopic information by ELF data at Moshiri. However, examining the microscopic properties of parent lightning as seen from the VHF SAFIR lightning detection network, has suggested very complicated characteristics of parent lightning discharges inducing sprites, as compared with the ELF data. One half of the sprite events are also found to be associated with + CG by the SAFIR observation, but another half has yielded rather new results as compared with earlier results. Four events are definitely associated with - CG and the remaining three events, inter-cloud flashes. The overall picture for Japanese winter sprites and their parent lightning discharges, is significantly different from that for the summer-time, continental sprites. This is indicative of complexity of winter lightning in the Hokuriku area of Japan and this would provide new information on the sprite generation mechanism.

New Intermetallic Compounds RE4Co2Mg3 (RE = Pr, Gd, Tb, Dy) – Syntheses, Structure, and Chemical Bonding

The magnesium compounds RE4Co2Mg3 (RE = Pr, Gd, Tb, Dy) were prepared by induction melting of the elements in sealed tantalum tubes. The samples were studied by powder X-ray diffraction. The structures of the gadolinium and of the terbium compound were refined from single crystal diffractometer data: Nd4Co2Mg3-type, P2/m, Z = 1, a = 754.0(4), b = 374.1(1), c = 822.5(3) pm, β = 109.65(4)°, wR2 = 0.0649, 730 F2 values for Gd4Co2Mg3 and a = 750.4(2), b = 372.86(6), c = 819.5(2) pm, β = 109.48(3)°, wR2 = 0.0398, 888 F2 values for Tb4Co2Mg3 with 30 variables each. The RE4Co2Mg3 structures are 3 : 1 intergrowth variants of distorted CsCl and AlB2 related slabs of compositions REMg and RECo2. Characteristic structural features (exemplary for Tb4Co2Mg3) are relatively short Tb-Co (271 pm), Co-Co (232 pm) and Mg-Mg (314 pm) distances. The latter are a geometrical constraint of the distortion of the REMg and RECo2 slabs. Chemical bonding analysis (ELF and ECOV data) for Gd4Co2Mg3 reveals strong Gd-Co bonding followed by Mg-Co, while the Mg-Mg interactions can be considered as weak. The Co-Co contacts are only weakly bonding. The bonding and antibonding states are almost filled.

VLF/ELF sferic evidence for in‐cloud discharge activity producing sprites

Sprite luminosities produced by winter lightning in Japan were found to be associated with simultaneous occurrences of clusters of radio atmospherics as observed in the VLF range, suggesting an in‐cloud discharge activity. Concurrent ELF data show transient perturbations, indicating continuous charge transfer in causative lightning. These data provide the first evidence that an in‐cloud discharge activity plays an important role in the generation mechanism of sprites.