showing 18 related works from this author
Spectral Observations of Optical Emissions Associated with Terrestrial Gamma-Ray Flashes
2021
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
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…
The CZT X-ray imager on AXO
2001
DSRI has initiated a development program of CZT X-ray and gamma ray detectors employing strip readout techniques. A dramatic improvement of the energy response was found operating the detectors as so-called drift detectors. For the electronic readout, modern ASIC chips were investigated. Modular design and the low power electronics will make large area detectors using the drift strip method feasible. The performance of a prototype CZT system will be presented and discussed. One such detector system has been proposed for future space missions: The X-Ray Imager (XRI) on the Atmospheric X-ray Observatory (AXO), which is a mission proposed to the Danish Small Satellite Program and is dedicated …
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…
A terrestrial gamma-ray flash and ionospheric ultraviolet emissions powered by lightning.
2020
Gamma-ray flash from a lightning leader Terrestrial gamma-ray flashes (TGFs) are millisecond pulses of gamma rays produced by thunderstorms. Neubert et al. observed a TGF from above, using instruments on the International Space Station. High-speed photometry in optical, ultraviolet, x-ray, and gamma-ray bands allowed them to determine the sequence of events that produced the TGF. Emission from an intracloud lightning leader was followed within a millisecond by the TGF. The subsequent lightning flash produced an electromagnetic pulse, which induced expanding waves of ultraviolet emission in the ionosphere above the thunderstorm, called an elve. The authors conclude that high electric fields …
A Simultaneous Observation of Lightning by ASIM, Colombia-Lightning Mapping Array, GLM, and ISS-LIS
2021
The Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) provides optical radiances and images of lightning flashes in several spectral bands. This work presents a lightning flash simultaneously observed from space by ASIM, the Geostationary Lightning Mapper (GLM) and the Lightning Imaging Sensor on the International Space Station (ISS-LIS); and from ground by the Colombia-Lightning Mapping Array (Colombia-LMA). Volumetric weather radar provides reflectivity data to help to interpret the effects of the cloud particles on the observed optical features. We found that surges in radiance in the band at 777.4 nm appear to be related mostly with lightning processe…
Observation of Terrestrial Gamma-Ray Flashes at Mid Latitude
2021
We present a sample of Terrestrial Gamma-ray Flashes (TGFs) observed at mid latitudes by the Atmosphere Space Interaction Monitor (ASIM). The events were detected between June 2018 and August 2020 in the latitude bands between 35° and 51° in both hemispheres, which we hereafter refer to as “mid latitudes.” The sample includes the first observations above urn:x-wiley:2169897X:media:jgrd57293:jgrd57293-math-0001 and consists of 14 events clustered in four geographical regions: north-west Atlantic and eastern USA; Mediterranean Sea; the ocean around South Africa; and north-eastern China and Siberia. We examine the characteristics of each event, both standalone and in the context of the global …
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.
Global Frequency and Geographical Distribution of Nighttime Streamer Corona Discharges (BLUEs) in Thunderclouds
2021
This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Blue Optical Observations of Narrow Bipolar Events by ASIM Suggest Corona Streamer Activity in Thunderstorms
2020
While narrow bipolar events (NBEs) could be related with lightning initiation, their intrinsic physics remains in question. Here we report on optical measurements by the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS) of blue flashes associated with NBEs. They are observed in a narrow blue band centered at 337 nm, with no simultaneous activity at 777.4 nm, considered a strong lightning emission line. From radio waves measured from the ground, we find that 7 of 10 single-pulse blue events can be identified as positive NBEs. The source altitudes estimated from optical and radio signals agree and indicate that the sources of the blue flashes are located be…
Atmosphere-Space Interactions Monitor, Instrument and First Results
2019
The Atmosphere-Space Interaction Monitor (ASIM) is an observatory mounted outside the Columbus module on the International Space Station. It has been operational since April 13th, 2018. It contains two instruments: The Modular X- and Gamma-ray Sensor (MXGS) and The Modular Multispectral Imaging Array (MMIA). The objective of ASIM is to monitor thunderstorms and auroras, including lightning discharges, especially discharges upwards above thunderstorms. This paper presents the instrument package and some first results.
The Modular X- and Gamma-Ray Sensor (MXGS)of the ASIM Payload on the International Space Station
2019
The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together with the Modular Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al. this issue) MXGS constitutes the instruments of the Atmosphere-Space Interactions Monitor (ASIM) (Neubert et al. this issue). The main objectives of MXGS are to image and measure the spectrum of X- and γ-rays from lightning discharges, known as Terrestrial Gamma-ray Flashes (TGFs), and for MMIA to image and perform high speed photometry of Transient Luminous Events (TLEs) and lightning discharges. With these two instruments sp…
Comparison of high‐speed optical observations of a lightning flash from space and the ground
2020
We analyze a nighttime negative cloud-to-ground lightning flash in Colombia observed from the ground with a high-speed camera at 5,000 images per second and from space by the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS), the Lightning Imaging Sensor also on the ISS (ISS-LIS), and the Geostationary Lightning Mapper (GLM) on GOES-16. The space instruments measure the oxygen band at 777.4 nm, allowing for direct comparisons of measurements, and the ground-based camera observes in a wide visible band. After conversion to energy emitted at the cloud top, we find a good linear correspondence of the optical energies measured by the three space instruments, …
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…
Observatory science with eXTP
2019
Disponible preprint en: arXiv:1812.04023v1 [astro-ph.HE] [v1] Mon, 10 Dec 2018 19:00:52 UTC (4,376 KB)
Blue Flashes as Counterparts to Narrow Bipolar Events: the Optical Signal of Shallow In-Cloud Discharges
2021
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Modeling lightning observations from space-based platforms (CloudScat.jl 1.0)
2020
This is an open access article. This work is distributed under the Creative Commons Attribution 4.0 License.
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…