scholarly journals The effect of magnetic substorms on near-ground atmospheric current

2000 ◽  
Vol 18 (12) ◽  
pp. 1623-1629 ◽  
Author(s):  
E. Belova ◽  
S. Kirkwood ◽  
H. Tammet
Keyword(s):  
Electric Fields ◽  
Statistical Significance ◽  
Atmospheric Electricity ◽  
Electric Circuit ◽  
Local Times ◽  
Wire Antenna ◽  
Time Interval ◽  
Early Recovery ◽  
Superposed Epoch Analysis ◽  
Electric Fields And Currents

Abstract. Ionosphere-magnetosphere disturbances at high latitudes, e.g. magnetic substorms, are accompanied by energetic particle precipitation and strong variations of the ionospheric electric fields and currents. These might reasonably be expected to modify the local atmospheric electric circuit. We have analysed air-earth vertical currents (AECs) measured by a long wire antenna at Esrange, northern Sweden during 35 geomagnetic substorms. Using superposed epoch analysis we compare the air-earth current variations during the 3 h before and after the time of the magnetic X-component minimum with those for corresponding local times on 35 days without substorms. After elimination of the average daily variation we can conclude that the effect of substorms on AEC is small but distinguishable. It is speculated that the AEC increases observed during about 2 h prior to the geomagnetic X-component minimum, are due to enhancement of the ionospheric electric field. During the subsequent 2 h of the substorm recovery phase, the difference between "substorm" and "quiet" atmospheric currents decreases. The amplitude of this "substorm" variation of AEC is estimated to be less than 50% of the amplitude of the diurnal variation in AEC during the same time interval. The statistical significance of this result was confirmed using the Van der Waerden X-test. This method was further used to show that the average air-earth current and its fluctuations increase during late expansion and early recovery phases of substorms.Key words: Ionosphere (electric fields and currents) · Magnetospheric physics (storms and substorms) · Meteorology and atmospheric dynamics (atmospheric electricity)

scholarly journals Some features of stepped and dart-stepped leaders near the ground in natural negative cloud-to-ground lightning discharges

2002 ◽  
Vol 20 (6) ◽  
pp. 863-870 ◽  
Author(s):  
X. Qie ◽  
Y. Yu ◽  
C. Guo ◽  
P. Laroche ◽  
G. Zhang ◽  
...  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Broad Band ◽  
Atmospheric Electricity ◽  
Antenna System ◽  
Time Interval ◽  
Return Stroke ◽  
Radio Science ◽  
Lightning Discharges ◽  
Log Normal

Abstract. Characteristics of the electric fields produced by stepped and dart-stepped leaders 200 µs just prior to the return strokes during natural negative cloud-to-ground (CG) lightning discharges have been analyzed by using data from a broad-band slow antenna system with 0.08 µs time resolution in southeastern China. It has been found that the electric field changes between the last stepped leader and the first return stroke could be classified in three categories. The first type is characterized by a small pulse superimposed on the abrupt beginning of the return stroke, and accounts for 42% of all the cases. The second type accounts for 33.3% and is characterized by relatively smooth electric field changes between the last leader pulse and the following return stroke. The third type accounts for 24.7%, and is characterized by small pulses between the last recognizable leader pulse and the following return stroke. On the average, the time interval between the successive leader pulses prior to the first return strokes and subsequent return strokes was 15.8 µs and 9.4 µs, respectively. The distribution of time intervals between successive stepped leader pulses is quite similar to Gaussian distribution while that for dart-stepped leader pulses is more similar to a log-normal distribution. Other discharge features, such as the average time interval between the last leader step and the first return stroke peak, the ratio of the last leader pulse peak to that of the return stroke amplitude are also discussed in the paper.Key words. Meteology and atmospheric dynamics (atmospheric electricity; lightning) – Radio science (electromagnetic noise and interference)

scholarly journals Retrieving Global Wilson Currents from Electrified Clouds Using Satellite Passive Microwave Observations

2018 ◽  
Vol 35 (7) ◽  
pp. 1487-1503 ◽  
Author(s):  
Michael Peterson ◽  
Wiebke Deierling ◽  
Chuntao Liu ◽  
Douglas Mach ◽  
Christina Kalb
Keyword(s):  
High Altitude ◽  
Electric Fields ◽  
Atmospheric Electricity ◽  
Electric Circuit ◽  
Radar Data ◽  
Passive Microwave ◽  
Retrieval Algorithm ◽  
Lateral Extent ◽  
Average Current ◽  
Scientific Accuracy

AbstractHigh-altitude atmospheric electricity measurements have been used to calculate the conduction (Wilson) currents that are supplied to the global electric circuit (GEC) by individual electrified clouds. Quantifying the global average current and assessing its temporal variability is a challenge, however, because it requires measurements in every stormy region of the world. Thus, a retrieval algorithm has been developed to infer the electric fields and Wilson currents above electrified weather from NASA ER-2 passive microwave high-altitude aircraft observations that are also common satellite products.This study documents the adaptation of the passive microwave electric field and the Wilson current retrieval algorithm for use with satellite platforms. Three distinct variants on the algorithm are produced to respond to specific use cases that differ in 1) whether swath or microwave feature data are available to describe the lateral extent of electrified clouds, 2) the availability of coincident radar data to characterize the vertical structure of electrified clouds, and 3) the prioritization of scientific accuracy or computational expense and product latency. The Wilson currents produced by the satellite retrievals are compared with each other and also with coincident lightning measurements and the Carnegie curve. The advantages, caveats, and limitations of each variant are discussed.

scholarly journals Challenges in coupling atmospheric electricity with biological systems

2020 ◽  
Vol 65 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Ellard R. Hunting ◽  
James Matthews ◽  
Pablo Fernández de Arróyabe Hernáez ◽  
Sam J. England ◽  
Konstantinos Kourtidis ◽  
...  
Keyword(s):  
Electric Fields ◽  
Biological Systems ◽  
Atmospheric Electricity ◽  
Electric Circuit ◽  
Small Scale ◽  
Biological Processes ◽  
Biological Organization ◽  
Lightning Strikes ◽  
Terrestrial Environments ◽  
The Relationship

AbstractThe atmosphere is host to a complex electric environment, ranging from a global electric circuit generating fluctuating atmospheric electric fields to local lightning strikes and ions. While research on interactions of organisms with their electrical environment is deeply rooted in the aquatic environment, it has hitherto been confined to interactions with local electrical phenomena and organismal perception of electric fields. However, there is emerging evidence of coupling between large- and small-scale atmospheric electrical phenomena and various biological processes in terrestrial environments that even appear to be tied to continental waters. Here, we synthesize our current understanding of this connectivity, discussing how atmospheric electricity can affect various levels of biological organization across multiple ecosystems. We identify opportunities for research, highlighting its complexity and interdisciplinary nature and draw attention to both conceptual and technical challenges lying ahead of our future understanding of the relationship between atmospheric electricity and the organization and functioning of biological systems.

Atmospheric Electricity in the Solar System

2019 ◽  
Author(s):  
Karen Aplin ◽  
Georg Fischer
Keyword(s):  
Solar System ◽  
Electric Fields ◽  
Atmospheric Chemistry ◽  
Atmospheric Electricity ◽  
Electric Circuit ◽  
Radiative Properties ◽  
Cloud Formation ◽  
Lightning Strikes ◽  
The Earth ◽  
Long Time

Electricity occurs in atmospheres across the Solar System planets and beyond, spanning spectacular lightning displays in clouds of water or dust, to more subtle effects of charge and electric fields. On Earth, lightning is likely to have existed for a long time, on the basis of evidence from fossilized lightning strikes in ancient rocks, but observations of planetary lightning are necessarily much more recent. The generation and observations of lightning and other atmospheric electrical processes, both from within-atmosphere measurements, and spacecraft remote sensing, can be readily studied using a comparative planetology approach, with the Earth as a model. All atmospheres contain charged molecules, electrons, and/or molecular clusters created by ionization from cosmic rays and other processes, which may affect an atmosphere’s energy balance both through aerosol and cloud formation and direct absorption of radiation. Several planets are anticipated to host a “global electric circuit” by analogy with the circuit occurring on the Earth, where thunderstorms drive the current of ions or electrons through weakly conductive parts of the atmosphere. This current flow may further modulate an atmosphere’s radiative properties through cloud and aerosol effects. Lightning could potentially have implications for life through its effects on atmospheric chemistry and particle transport. It has been observed on many of the Solar System planets (Earth, Jupiter, Saturn, Uranus, and Neptune), and it may also be present on Venus and Mars. On Earth, Jupiter, and Saturn, lightning is thought to be generated in deep water and ice clouds, but discharges can be generated in dust, as for terrestrial volcanic lightning, and on Mars. Other, less well-understood mechanisms causing discharges in non-water clouds also seem likely. The discovery of thousands of exoplanets has recently led to a range of further exotic possibilities for atmospheric electricity, though lightning detection beyond our Solar System remains a technical challenge to be solved.

scholarly journals Bicyclol for the treatment of drug-induced liver injury: a propensity score matching analysis using a nationwide inpatient database

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052110059
Author(s):  
Yongfeng Wang ◽  
Rongtao Lai ◽  
Peilan Zong ◽  
Qingling Xu ◽  
Jia Shang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Propensity Score ◽  
Propensity Score Matching ◽  
Statistical Significance ◽  
Control Group ◽  
Time Interval ◽  
Potential Candidate ◽  
Drug Induced ◽  
Drug Induced Liver Injury ◽  
Propensity Score Matching Analysis

ObjectiveTo evaluate the efficacy and safety of bicyclol in patients with drug-induced liver injury (DILI) using a nationwide database.MethodsWe retrospectively analyzed the clinical data of DILI patients in the DILI-R database. Propensity score matching was performed to balance the bicyclol and control groups, and alanine aminotransferase (ALT) recovery was compared between the two groups. Factors associated with ALT recovery and safety were identified.ResultsThe analysis included the data of 25,927 patients. Eighty-seven cases were included in the bicyclol group, with 932 cases in the control group. One-to-one propensity score matching created 86 matched pairs. The ALT normalization rate in the bicyclol group was significantly higher than that in the control group (50.00% vs. 24.42%), and statistical significance was found in the superiority test. After adjustment of baseline ALT levels, baseline total bilirubin levels, sex, age, acute or chronic liver diseases, and suspected drugs in the multivariate logic regression analysis, the major influencing factors for ALT recovery included the time interval between ALT tests (days) and the group factor (bicyclol treatment). There were no differences in the proportion of renal function impairment or blood abnormalities between the two groups.ConclusionsBicyclol is a potential candidate for DILI.

Computational assessment of effects of electric fields and currents in tokamak edge plasmas

1995 ◽  
Vol 220-222 ◽  
pp. 982-986 ◽  
Author(s):  
M. Baelmans ◽  
D. Reiter ◽  
R.R. Weynants ◽  
R. Schneider
Keyword(s):  
Electric Fields ◽  
Tokamak Edge ◽  
Edge Plasmas ◽  
Electric Fields And Currents

scholarly journals Effects of solar eclipse on the electrodynamical processes of the equatorial ionosphere: a case study during 11 August 1999 dusk time total solar eclipse over India

2002 ◽  
Vol 20 (12) ◽  
pp. 1977-1985 ◽  
Author(s):  
R. Sridharan ◽  
C. V. Devasia ◽  
N. Jyoti ◽  
Diwakar Tiwari ◽  
K. S. Viswanathan ◽  
...  
Keyword(s):  
Electric Fields ◽  
Solar Eclipse ◽  
Equatorial Ionosphere ◽  
Hf Radar ◽  
F Region ◽  
Large Enhancement ◽  
Temporal Structures ◽  
E Region ◽  
Field Lines ◽  
Electric Fields And Currents

Abstract. The effects on the electrodynamics of the equatorial E- and F-regions of the ionosphere, due to the occurrence of the solar eclipse during sunset hours on 11 August 1999, were investigated in a unique observational campaign involving ground based ionosondes, VHF and HF radars from the equatorial location of Trivandrum (8.5° N; 77° E; dip lat. 0.5° N), India. The study revealed the nature of changes brought about by the eclipse in the evening time E- and F-regions in terms of (i) the sudden intensification of a weak blanketing ES-layer and the associated large enhancement of the VHF backscattered returns, (ii) significant increase in h' F immediately following the eclipse and (iii) distinctly different spatial and temporal structures in the spread-F irregularity drift velocities as observed by the HF radar. The significantly large enhancement of the backscattered returns from the E-region coincident with the onset of the eclipse is attributed to the generation of steep electron density gradients associated with the blanketing ES , possibly triggered by the eclipse phenomena. The increase in F-region base height immediately after the eclipse is explained as due to the reduction in the conductivity of the conjugate E-region in the path of totality connected to the F-region over the equator along the magnetic field lines, and this, with the peculiar local and regional conditions, seems to have reduced the E-region loading of the F-region dynamo, resulting in a larger post sunset F-region height (h' F) rise. These aspects of E-and F-region behaviour on the eclipse day are discussed in relation to those observed on the control day.Key words. Ionosphere (electric fields and currents; equatorial ionosphere; ionospheric irregularities)

scholarly journals Regional estimation of electric fields and currents in the polar ionosphere

1995 ◽  
Vol 22 (3) ◽  
pp. 283-286 ◽  
Author(s):  
Mariko Sato ◽  
Y. Kamide ◽  
A. D. Richmond ◽  
A. Brekke ◽  
S. Nozawa
Keyword(s):  
Electric Fields ◽  
Polar Ionosphere ◽  
Regional Estimation ◽  
Electric Fields And Currents

scholarly journals The Global Electric Circuit and Global Seismicity

Geosciences ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 491
Author(s):  
Sergey Pulinets ◽  
Galina Khachikyan
Keyword(s):  
Electric Fields ◽  
Ground Surface ◽  
Electric Circuit ◽  
Thunderstorm Activity ◽  
Radon Emanation ◽  
Global Electric Circuit ◽  
Important Conclusion ◽  
Earthquake Preparation ◽  
Deep Focus ◽  
Ionospheric Potential

Basing on the catalogue of earthquakes with a magnitude of M ≥ 4.5 for the period 1973–2017, a UT variation with an amplitude of ~10% in the number of earthquakes is revealed and compared with a UT variation in the ionospheric potential (IP) with an amplitude of ~18%. We demonstrate that the amplitude of the UT variation in the number of deep-focus earthquakes is greater compared with that of crustal earthquakes, reaching 19%. The UT of the primary maxima of both the IP (according to modern calculations) and of earthquake incidence coincides (near 17:00 UT) and is, by 2 h, ahead of the classical Carnegie curve representing the UT variation in the atmospheric electric field on the ground surface. The linear regression equation between these UT variations in the number of deep-focus earthquakes and the ionospheric potential is obtained, with a correlation coefficient of R = 0.97. The results support the idea that the processes of earthquake preparation are coupled to the functional processes of the global electric circuit and the generation of atmospheric electric fields. In particular, the observed increase in thunderstorm activity over earthquake preparation areas, provided by air ionization due to radon emanation, yields a clue as to why the global thunderstorm distribution is primarily continental. Another important conclusion is that, in observing the longitudinal distributions of earthquakes against the IP distribution, we automatically observe that all such events occur in local nighttime hours. Considering that the majority of earthquake precursors have their maximums at local night and demonstrating the positive deviation from the undisturbed value, we obtain a clue as to its positive correlation with variations in the ionospheric potential.

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