scholarly journals Ground-level observation of a terrestrial gamma ray flash initiated by a triggered lightning

2016 ◽  
Vol 121 (11) ◽  
pp. 6511-6533 ◽  
Author(s):  
B. M. Hare ◽  
M. A. Uman ◽  
J. R. Dwyer ◽  
D. M. Jordan ◽  
M. I. Biggerstaff ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level ◽  
Triggered Lightning

scholarly journals A ground level gamma-ray burst observed in association with rocket-triggered lightning

2004 ◽  
Vol 31 (5) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. R. Dwyer ◽  
H. K. Rassoul ◽  
M. Al-Dayeh ◽  
L. Caraway ◽  
B. Wright ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level ◽  
Gamma Ray Burst ◽  
Triggered Lightning

scholarly journals Gamma Ray Showers Observed at Ground Level in Coincidence With Downward Lightning Leaders

2018 ◽  
Vol 123 (13) ◽  
pp. 6864-6879 ◽  
Author(s):  
R. U. Abbasi ◽  
T. Abu‐Zayyad ◽  
M. Allen ◽  
E. Barcikowski ◽  
J. W. Belz ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level

Radionuclides in the ground-level atmosphere in Vilnius, Lithuania, in March 2011, detected by gamma-ray spectrometry

2012 ◽  
Vol 109 ◽  
pp. 13-18 ◽  
Author(s):  
A. Gudelis ◽  
R. Druteikienė ◽  
G. Lujanienė ◽  
E. Maceika ◽  
A. Plukis ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level ◽  
Gamma Ray Spectrometry

Ground-level observation of terrestrial gamma-ray bursts initiated by lightning

2017 ◽  
Author(s):  
Xiao-Qiang Li ◽  
Ru-Bin Jiang ◽  
Yi Zheng ◽  
Hong-Zhao Zhou ◽  
Bin Xing ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level ◽  
Gamma Ray Bursts

scholarly journals In situ physical and chemical characterisation of the Eyjafjallajökull aerosol plume in the free troposphere over Italy

2014 ◽  
Vol 14 (2) ◽  
pp. 1075-1092 ◽  
Author(s):  
S. Sandrini ◽  
L. Giulianelli ◽  
S. Decesari ◽  
S. Fuzzi ◽  
P. Cristofanelli ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Gamma Ray ◽  
Fine Fraction ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Ground Level ◽  
Coarse Fraction ◽  
Volcanic Plume ◽  
Physical And Chemical ◽  
Aerosol Plume

Abstract. Continuous measurements of physical and chemical properties at the Mt. Cimone (Italy) GAW-WMO (Global Atmosphere Watch, World Meteorological Organization) Global Station (2165 m a.s.l.) have allowed the detection of the volcanic aerosol plume resulting from the Eyjafjallajökull (Iceland) eruption of spring 2010. The event affected the Mt. Cimone site after a transport over a distance of more than 3000 km. Two main transport episodes were detected during the eruption period, showing a volcanic fingerprint discernible against the free tropospheric background conditions typical of the site, the first from April 19 to 21 and the second from 18 to 20 May 2010. This paper reports the modification of aerosol characteristics observed during the two episodes, both characterised by an abrupt increase in fine and, especially, coarse mode particle number. Analysis of major, minor and trace elements by different analytical techniques (ionic chromatography, particle induced X-ray emission–particle induced gamma-ray emission (PIXE–PIGE) and inductively coupled plasma mass spectrometry (ICP-MS)) were performed on aerosols collected by ground-level discrete sampling. The resulting database allows the characterisation of aerosol chemical composition during the volcanic plume transport and in background conditions. During the passage of the volcanic plume, the fine fraction was dominated by sulphates, denoting the secondary origin of this mode, mainly resulting from in-plume oxidation of volcanic SO2. By contrast, the coarse fraction was characterised by increased concentration of numerous elements of crustal origin, such as Fe, Ti, Mn, Ca, Na, and Mg, which enter the composition of silicate minerals. Data analysis of selected elements (Ti, Al, Fe, Mn) allowed the estimation of the volcanic plume's contribution to total PM10, resulting in a local enhancement of up to 9.5 μg m−3, i.e. 40% of total PM10 on 18 May, which was the most intense of the two episodes. These results appear significant, especially in light of the huge distance of Mt. Cimone from the source, confirming the widespread diffusion of the Eyjafjallajökull ashes over Europe.

STUDIES IN THE ACTIVE DEPOSIT OF ACTINIUM: PART II: THE DECAY OF 211Pb (AcB)

1965 ◽  
Vol 43 (3) ◽  
pp. 383-403 ◽  
Author(s):  
C. R. Cothern ◽  
R. D. Connor
Keyword(s):  
Gamma Rays ◽  
Level Scheme ◽  
Gamma Ray ◽  
Ground Level ◽  
Conversion Line ◽  
Point Energy ◽  
Correlation Studies ◽  
Absolute Intensities ◽  
Gamma Coincidence ◽  
Conversion Coefficients

Studies of the active deposit of actinium using a Siegbahn–Slatis beta-ray spectrometer and scintillation counters together with gamma–gamma coincidence work and gamma–gamma angular correlation measurements have led to the establishment of a new decay scheme for 211Pb and a level scheme for 211Bi involving five excited states.The gamma rays have the following energies and absolute intensities:[Formula: see text]Conversion-line studies yielded energy values for the transitions marked with an asterisk as 403.3 ± 0.5 and 426.5 ± 0.5 keV respectively. The K conversion coefficients of the 400- and 430-keV transitions have been determined as 0.091 ± 0.018 and 0.117 ± 0.024 respectively.Fermi analysis yields 1.378 MeV as the highest end-point energy of the beta partial spectra. The remaining end points and the component intensities as deduced from the level scheme are as follows:[Formula: see text]The much less accurate results from Fermi analysis of the complete active deposit are in reasonable agreement with these data.Angular correlation studies of the 430–400- and 706–400-keV gamma-ray cascades have yielded spins for the levels concerned: ground level (9/2), 400-keV level (7/2), 830-keV level (9/2), and 1 100-keV level (7/2). These spins are the only ones consistent with the experimental evidence and the theoretical arguments presented.

scholarly journals Evolution Characteristics during Initial Stage of Triggered Lightning Based on Directly Measured Current

Atmosphere ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 658
Author(s):  
Zefang Chen ◽  
Yang Zhang ◽  
Yanfeng Fan ◽  
Jingxuan Wang ◽  
Dong Zheng ◽  
...  
Keyword(s):  
Lightning Discharge ◽  
Ground Level ◽  
Current Data ◽  
Discharge Process ◽  
Measured Current ◽  
Critical Range ◽  
Initial Stage ◽  
Evolution Characteristics ◽  
Triggered Lightning ◽  
Initial Process

The initiation of a leader is an important lightning discharge process, but how an upward positive leader (UPL) initiates is still not fully understood. The evolution characteristics of a UPL during its initial stage was systematically studied based on directly measured current data of 14 triggered lightning events in 2019. It was found that the initial stage of triggered lightning can be divided into two types: a single initial process form and a multiple initial process form, with percentages of 64.29% and 35.71%, respectively. Compared with the former, the latter usually lasts longer, and the corresponding lightning is often triggered under a lower ground-level quasi-static electric field. In each initial process, precursor current pulses (PCPs), PCP clusters and initial precursor current pulse (IPCPs) are typical current waveforms, and the pulse durations and transferred charges of PCPs increase linearly with time. However, in the multiple initial process form, the pulse durations and transferred charges of PCPs will reduce significantly after each previous initial process and then continue to increase in the following initial process. In each initial process, when the pulse duration and transferred charge of a PCP increase to a certain extent, PCP clusters and IPCPs begin to appear. For the emergence of PCP clusters, the average values of the threshold are 3.48 μs and 19.53 μC, respectively. For the occurrence of IPCPs, the corresponding values are 4.69 μs and 27.23 μC, respectively. The average values of pulse durations and transferred charges of IPCPs are larger than those of PCP clusters. Compared with adjacent PCP clusters, IPCPs contain more pulses, with a critical range of 6–7. IPCPs also last longer, and have a critical range of 138–198 μs.

SEARCH FOR ENHANCEMENTS OF MUONS AT SEA LEVEL FROM TRANSIENT EVENTS

2005 ◽  
Vol 20 (29) ◽  
pp. 6941-6943
Author(s):  
C. R. A. AUGUSTO ◽  
C. E. NAVIA ◽  
M. B. ROBBA
Keyword(s):  
Solar Flare ◽  
Sea Level ◽  
Gamma Ray ◽  
Unknown Origin ◽  
Ground Level ◽  
X Ray ◽  
Raster Scan ◽  
Main Target ◽  
Transient Events ◽  
Ground Level Enhancements

The main target of this study is a search for the origin of two ground level enhancements (GLEs), observed on December of 2003 at sea level by using the TUPI muon telescope. The results show that one of them has a strong correlation with solar flare, while the other has an unknown origin, because there is not satellite report of solar flare, nor the prompt X-ray emission and neither the excess of nuclei during the raster scan where the GLE was observed. Even so, two possibilities are analyzed: the solar flare hypothesis and the gamma ray burst (GRB) hypothesis.

OBSERVATION OF MUON EXCESS AT GROUND LEVEL IN RELATION TO GAMMA-RAY BURSTS DETECTED FROM SPACE

2015 ◽  
Vol 805 (1) ◽  
pp. 69 ◽  
Author(s):  
C. R. A. Augusto ◽  
C. E. Navia ◽  
M. N. de Oliveira ◽  
K. H. Tsui ◽  
A. A. Nepomuceno ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Ground Level ◽  
Gamma Ray Bursts
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