0000000000179986

AUTHOR

Nikolai Lehtinen

0000-0003-1739-0837

showing 6 related works from this author

Radio emissions from double RHESSI TGFs

2016

Abstract A detailed analysis of Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) terrestrial gamma ray flashes (TGFs) is performed in association with World Wide Lightning Location Network (WWLLN) sources and very low frequency (VLF) sferics recorded at Duke University. RHESSI clock offset is evaluated and found to experience changes on the 5 August 2005 and 21 October 2013, based on the analysis of TGF‐WWLLN matches. The clock offsets were found for all three periods of observations with standard deviations less than 100 μs. This result opens the possibility for the precise comparative analyses of RHESSI TGFs with the other types of data (WWLLN, radio measurements, etc.) In ca…

Atmospheric ScienceHigh energy010504 meteorology & atmospheric sciencesAtmospheric ElectricityFOS: Physical sciencesRHESSI clock offsetterrestrial gamma ray flashesAstrophysicsRadio atmospheric01 natural sciencesLightningPhysical Geography and Environmental GeoscienceAerosol and CloudsAtmospheric SciencesRemote SensingPhysics - Space Physics0103 physical sciencesEarth and Planetary Sciences (miscellaneous)Instruments and TechniquesVery low frequency010303 astronomy & astrophysicsResearch ArticlesTGF‐WWLLN match0105 earth and related environmental sciencesRadiative ProcessesPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)Remote Sensing and DisastersGamma raymultipeak TGFsWorld wideLightningRHESSI TGFsSpace Physics (physics.space-ph)Geophysicsradio emission from TGFClock offset13. Climate actionSpace and Planetary ScienceAtmospheric ProcessesAstrophysics - High Energy Astrophysical PhenomenaNatural HazardsResearch Article
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Constraining spectral models of a terrestrial gamma‐ray flash from a terrestrial electron beam observation by the Atmosphere‐Space Interactions Monit…

2021

Terrestrial Gamma ray Flashes (TGFs) are short flashes of high energy photons, produced by thunderstorms. When interacting with the atmosphere, they produce relativistic electrons and positrons, and a part gets bounded to geomagnetic field lines and travels large distances in space. This phenomenon is called a Terrestrial Electron Beam (TEB). The Atmosphere-Space Interactions Monitor (ASIM) mounted on-board the International Space Station detected a new TEB event on March 24, 2019, originating from the tropical cyclone Johanina. Using ASIM's low energy detector, the TEB energy spectrum is resolved down to 50 keV. We provide a method to constrain the TGF source spectrum based on the detected…

PhysicsAtmosphereGeophysicsCathode rayGeneral Earth and Planetary SciencesSpace (mathematics)Computational physicsTerrestrial gamma-ray flash
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The First Terrestrial Electron Beam Observed by the Atmosphere‐Space Interactions Monitor

2019

We report the first Terrestrial Electron Beam detected by the Atmosphere‐Space Interactions Monitor. It happened on 16 September 2018. The Atmosphere‐Space Interactions Monitor Modular X and Gamma ray Sensor recorded a 2 ms long event, with a softer spectrum than typically recorded for Terrestrial Gamma ray Flashes (TGFs). The lightning discharge associated to this event was found in the World Wide Lightning Location Network data, close to the northern footpoint of the magnetic field line that intercepts the International Space Station location. Imaging from a GOES‐R geostationary satellite shows that the source TGF was produced close to an overshooting top of a thunderstorm. Monte‐Carlo si…

Physics010504 meteorology & atmospheric sciencesElectronSpace (mathematics)01 natural sciencesComputational physicsAtmosphereGeophysicsEarth's magnetic fieldPositron13. Climate actionSpace and Planetary ScienceCathode rayThunderstorm0105 earth and related environmental sciencesJournal of Geophysical Research: Space Physics
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Simultaneous Observations of EIP, TGF, Elve, and Optical Lightning

2021

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.

PhysicsAtmospheric ScienceGeophysics010504 meteorology & atmospheric sciencesMeteorologySpace and Planetary Science0103 physical sciencesEarth and Planetary Sciences (miscellaneous)010303 astronomy & astrophysics01 natural sciencesLightningGeneralLiterature_REFERENCE(e.g.dictionariesencyclopediasglossaries)0105 earth and related environmental sciences
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Spectral Analysis of Individual Terrestrial Gamma-ray Flashes Detected by ASIM

2021

The Atmosphere-Space Interactions Monitor (ASIM) is the first instrument in space specifically designed to observe terrestrial gamma-ray flashes (TGFs). TGFs are high energy photons associated with lightning flashes and we perform the spectral analysis of 17 TGFs detected by ASIM. The TGF sample is carefully selected by rigorous selection criteria to keep a clean sample suitable for spectral analysis, that is, suitable count statistics, low instrumental effects, and reliable source location. Monte Carlo modeling of individual TGFs has been compared to the observed energy spectra to study the possible source altitudes and beaming geometries. A careful model of the instrumental effects has be…

PhysicsAtmospheric ScienceGeophysicsSpace and Planetary ScienceEarth and Planetary Sciences (miscellaneous)Gamma raySpectral analysisAstrophysicsLightning
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First 10 Months of TGF Observations by ASIM

2019

The Atmosphere‐Space Interactions Monitor (ASIM) was launched to the International Space Station on 2 April 2018. The ASIM payload consists of two main instruments, the Modular X‐ray and Gamma‐ray Sensor (MXGS) for imaging and spectral analysis of Terrestrial Gamma‐ray Flashes (TGFs) and the Modular Multi‐spectral Imaging Array for detection, imaging, and spectral analysis of Transient Luminous Events and lightning. ASIM is the first space mission designed for simultaneous observations of Transient Luminous Events, TGFs, and optical lightning. During the first 10 months of operation (2 June 2018 to 1 April 2019) the MXGS has observed 217 TGFs. In this paper we report several unprecedented m…

PhysicsAtmospheric SciencePathologymedicine.medical_specialty010504 meteorology & atmospheric sciences7. Clean energy01 natural sciencesLightning010305 fluids & plasmasGeophysics13. Climate actionSpace and Planetary Science0103 physical sciencesEarth and Planetary Sciences (miscellaneous)medicine0105 earth and related environmental sciences
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