Gravity waves, meteor trails and asymmetries in elves

From June 2008 to March 2011 more than 400 elves have been recorded by cameras in southern France and northeastern Spain. A considerable fraction of elves are not as uniform as predicted by theory. We demonstrate examples and analyses of events displaying an asymmetrical distribution of luminosity in elves, gravity wave patterns, and even elves not recognizeable as a ring, and a distinct meteor trail. Emissions were enhanced by the meteoric dust deposition. The observations imply that the conditions in the lower ionosphere significantly influence the luminosity output. Furthermore, certain elves were accompanied by unusual electromagnetic signals, and we discuss the symmetry of their polarity, meteorology and land/sea differences.Postprint (published version

Characteristics of lightning flashes generating dancing sprites above thunderstorms

During the night of October 29-30, 2013, a low-light video camera at Pic du Midi (2877 m) in the French Pyrénées, recorded TLEs above a very active storm over the Mediterranean Sea. The minimum cloud top temperature reached -73 °C at ~1600 UTC while its cloud to ground (CG) flash rate reached ~30 fl min-1. Some sprite events with long duration are classified as dancing sprites. We analyze in detail the temporal evolution and estimated location of sprite elements for two cases of these events. They consist in series of sprite sequences with a duration that exceeds 1 second. By associating the cloud structure, the lightning activity, the electric field radiated in a broad range of low frequencies and the current moment waveform of the lightning strokes, some findings are highlighted: (i) In each series, successive sprite sequences reflect the occurrence time and location of individual positive lightning strokes across the stratiform region. (ii) The longer time-delayed (> 20 ms) sprite elements correspond to the lower impulsive charge moment changes (iCMC) of the parent stroke (< 200 C km) and they are shifted few tens of kilometres from their SP+CG stroke. However, both short and long time-delayed sprite elements also occur after strokes that produce a large iCMC and that are followed by a continuing current. (iii) The long time-delayed sprite elements produced during the continuing current correspond to surges in the current moment waveform. They occur sometimes at an altitude apparently lower than the previous short time-delayed sprite elements, possibly because of the lowered altitude of the ionosphere potential. (iv) The largest and brightest sprite elements produce significant current signatures, visible when their delay is not too short (~3-5 ms).Preprin

Lightning Sferics:Analysis of the Instantaneous Phase and Frequency Inferred From Complex Waveforms

Analysis of very low frequency lightning waveforms, or radio sferics, can contribute to research into lower ionosphere perturbations and the corresponding atmospheric chemistry. Lightning waveforms can also be characterized on the basis of their propagation distance from receivers in order to study radio wave propagation. A bank of average waveforms, that is, the waveform bank, &lt;1,000 km with a spatial resolution of 10 km has been produced, based on the lightning waveforms recorded in Europe on 8 August 2014. These average lightning waveforms at different distances exhibit a sequence of consecutive maxima resulting from ionospheric reflections, named sky waves. The spectral waveform bank shows a sequence of consecutive modal maxima at different frequencies depending on distance. The Hilbert transform is applied to produce complex lightning waveforms, which provide additional information to the original real waveforms alone, that is, the instantaneous phase and frequency. The time differences calculated from the instantaneous phases of complex lightning waveforms give the minimum arrival time difference error when compared to other analyzed signal processing methods. The derivative of the instantaneous phase, that is, the instantaneous frequency, represents the amplitude-weighted average of frequency components at maximum amplitude according to theory and numerical simulation. In real experiments, the instantaneous frequency can be understood as the median value of the real frequency distribution calculated at maximum amplitude. It is found that the instantaneous frequencies at maximum amplitudes are distance dependent. This finding might enable the development of a novel method to determine lightning distances in the future.</p

Multi-instrumental analysis of large sprite events and of their producing storm in southwestern France

During the night of 01-02 September, 2009, several TLEs including 3 halos and 16 distinct sprites were observed above a storm in north-western Mediterranean Sea with a camera at Pic du Midi (42.93° N, 0.14° E, 2877 m). Some of the sprites were especially large with vertical and horizontal extension estimated at about 70 km and 80 km, respectively. The TLE sequence lasted about one hour during a storm which developed 9 hours earlier over northern Spain in a very unstable atmosphere (CAPE at about 2000 J kg-1). The storm was characterized by a very circular shape and a size of about 250×250 km2 (cloud top temperature lower than -30°C) when the TLEs were produced (0209-0307 UT). The cloud to ground (CG) flash rate was large (45 min-1) one hour before the first TLE was detected and very low ( 5 ms) was observed for the electric field in ELF range in the cases of the very large sprites. Data from a VLF receiver shows the association between large sprites and early VLF signal perturbations.Postprint (published version

Multi-instrumental observations of a positive gigantic jet produced by a winter thunderstorm in Europe

At 2336:56 UTC on 12 December 2009, a bright gigantic jet (GJ) was recorded by an observer in Italy. Forty-nine additional sprites, elves, halos and two cases of upward lightning were observed that night. The location of the GJ corresponded to a distinct cloud top (-34°C) west of Ajaccio, Corsica. The GJ reached approximately 91 km altitude, with a "trailing jet" reaching 49-59 km, matching with earlier reported GJs. The duration was short at 120-160 ms. This is the first documented GJ which emerged from a maritime winter thunderstorm only 6.5 km tall, showing high cloud tops are not required for initiation of GJs. In the presence of strong vertical wind shear, the meteorological situation was different from typical outbreaks of fall and winter thunderstorms in the Mediterranean. During the trailing jet phase of the GJ, a sprite with halo triggered by a nearby cloud-to-ground lightning flash occurred at a relatively low altitude (<72 km). At the same time, the trailing jet and beads were reilluminated. Electromagnetic waveforms from Hungary, Poland, and the USA revealed this GJ is the first reported to transfer negative charge (approximately 136 C) from the ionosphere to the positively charged origins in the cloud (i.e., a positive cloud-to-ionosphere discharge, +CI), with a large total charge moment change of 11600 C km and a maximum current of 3.3 kA. Early VLF transmitter amplitude perturbations detected concurrently with the GJ confirm the production of large conductivity changes due to electron density enhancements in the D-region of the ionosphere. Copyright 2010 by the American Geophysical Union

Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p &lt; 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM &gt; 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM &gt; 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

Data for the publication 'Global Lightning Quanta'

This data is to illustrate the theory, data analysis, and exemplary results of the data described in the corresponding publication entitled 'Global Lightning Quanta'.Full details of the methodology may be found in the associated manuscript.The data is described in three different forms that build on each other in a logical and hierarchical order. (1) High level description: All the data is described in textual form in the corresponding publication in extensive detail. (2) Middle level description: The actual values of the data and their units which are used in the publication are embedded in the corresponding standard Matlab .m files, one for each Figure. The Matlab programming language is explained on the website https://uk.mathworks.com/help/matlab/getting-started-with-matlab.html?s_cid=learn_doc (3) Low level description: The binary data used by the Matlab .m files are embedded in the corresponding Matlab .mat files, one for each Figure. These .mat files are independent of the computing platform used

Data for the publication "Simulation of Earth-Ionosphere Cavity Resonances with Lightning Flashes Reported by OTD/LIS"

This data is to illustrate the theory, data analysis, and exemplary results of the data described in the corresponding publication entitled 'Simulation of Earth-Ionosphere Cavity Resonances with Lightning Flashes Reported by OTD/LIS'.This data lives in the context of the corresponding publication entitled 'Simulation of Earth-Ionosphere Cavity Resonances with Lightning Flashes Reported by OTD/LIS'. Any use of the data outside this specific context is considered to be unethical. The data is described in three different forms that build on each other in a logical and hierarchical order. (1) High level description: All the data is described in textual form in the corresponding publication in extensive detail. (2) Middle level description: The actual values of the data and their units which are used in the publication are embedded in the corresponding standard Matlab .m files, one for each Figure. The Matlab programming language is explained on the website https://uk.mathworks.com/help/matlab/getting-started-with-matlab.html?s_cid=learn_doc (3) Low level description: The binary data used by the Matlab .m files are embedded in the corresponding Matlab .mat files, one for each Figure. These .mat files are independent of the computing platform used.The work contributes to the United Nations Sustainable Development Goal on Climate Action (SDG13) to build knowledge and capacity to meet climate change (target 2.3 13.3)