Source Altitudes of Optical Emissions Associated with TGFs

2020 ◽  
Author(s):  
Matthias Heumesser ◽  
Olivier Chanrion ◽  
Torsten Neubert ◽  
Krystallia Dimitriadou ◽  
Christoph Köhn ◽  
...  
Keyword(s):  
Optical Pulse ◽  
Gamma Ray ◽  
Space Station ◽  
Optical Path ◽  
Optical Analysis ◽  
Cloud Properties ◽  
Lightning Current ◽  
Optical Paths ◽  
Imaging Sensor ◽  
Narrow Bands

<p>Terrestrial Gamma-Ray Flashes (TGFs) observed from space appear to be generated after a few milliseconds of optical activity and before the onset of a main optical pulse. The pre-activity is thought to be from a propagating leader and the main optical pulse the emissions from the ensuing stroke. Scattering of photons in the cloud increases the rise time and durations of the pulses and thus allows for estimates of their optical path from their sources.</p><p>In this presentation we estimate the depth inside thunderclouds of pulses associated with more than 100 TGFs observed by the Atmosphere-Space Interactions Monitor (ASIM) on the International Space Station (ISS). The observations are in narrow bands at 337 nm, to include the strongest line of N<sub>2</sub>2P and 777.4 nm of OI, considered a strong lightning emission line. With the assumption that the sources are instantaneous and at single points within a cloud, we find optical paths for the events by using typical cloud properties. Combined with cloud top heights from a recent study on TGF producing thunderstorms, this gives an estimate at which altitude the optical detections are produced.</p><p>Data from VAISALA’s lightning location network GLD360 and NASA’s Lightning Imaging Sensor on the ISS (ISS-LIS) will be used to assess the results from the optical analysis. This includes investigations of the correlations between TGF durations, detected peak lightning current and optical path in the cloud.</p>

A terrestrial gamma-ray flash and ionospheric ultraviolet emissions powered by lightning

Science ◽  
2019 ◽  
pp. eaax3872 ◽  
Author(s):  
Torsten Neubert ◽  
Nikolai Østgaard ◽  
Victor Reglero ◽  
Olivier Chanrion ◽  
Matthias Heumesser ◽  
...  
Keyword(s):  
Electric Fields ◽  
Electromagnetic Waves ◽  
Gamma Ray ◽  
Early Stage ◽  
Space Station ◽  
Lower Ionosphere ◽  
High Amplitude ◽  
Lightning Flash ◽  
Lightning Current ◽  
Ultraviolet Emissions

Terrestrial gamma-ray flashes (TGFs) are transient gamma-ray emissions from thunderstorms, generated by electrons accelerated to relativistic energies in electric fields. Elves are ultraviolet and optical emissions excited in the lower ionosphere by electromagnetic waves radiated from lightning current pulses. We observe a TGF and an associated Elve using the Atmosphere-Space Interactions Monitor on the International Space Station. The TGF occurs at the onset of a lightning current pulse that generates an Elve, in the early stage of a lightning flash. Our measurements suggest that the current onset is fast and has a high amplitude, a prerequisite for Elves, and that the TGF is generated in the electric fields associated with the lightning leader.

scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals Three years of the Lightning Imaging Sensor onboard the International Space Station: Expanded Global Coverage and Enhanced Applications

2020 ◽  
Author(s):  
Timothy J Lang ◽  
Richard Blakeslee ◽  
William J. Koshak ◽  
Dennis E. Buechler ◽  
Patrick Gatlin ◽  
...  
Keyword(s):  
International Space Station ◽  
Space Station ◽  
International Space ◽  
Global Coverage ◽  
Imaging Sensor

ASIM TGFs associated with high peak current strokes

2021 ◽  
Author(s):  
Andrey Mezentsev ◽  
Nikolai Østgaard ◽  
Torsten Neubert ◽  
Victor Reglero
Keyword(s):  
International Space Station ◽  
Short Duration ◽  
Gamma Ray ◽  
Space Station ◽  
High Peak ◽  
Science Data ◽  
Peak Current ◽  
International Space ◽  
Lightning Discharges

<p>The Atmosphere-Space Interactions Monitor (ASIM) has been installed on board of the International Space Station in April 2018, successfully providing science data for 2.5 years. The Modular X- and Gamma-ray Sensor (MXGS) of ASIM is designed to detect Terrestrial Gamma-ray Flashes (TGFs) (short intense bursts of gamma-ray photons), produced during the initial breakdown phase of the +IC lightning discharges.</p><p> </p><p>In this contribution we report and summarize the results on the ASIM TFGs associated with high peak current lightning detections (detected by GLD and WWLLN networks). High peak current detections tend to be associated with short duration TGFs and do not exhibit a tendency to correlate with the fluence of the TGF.</p>

scholarly journals Atmosphere-Space Interactions Monitor (ASIM): State of the Art

2014 ◽  
Vol 1 (1) ◽  
pp. 303-306
Author(s):  
Pere Blay ◽  
Lola Sabau-Graziati ◽  
Víctor Reglero ◽  
Paul H. Connell ◽  
Juana M. Rodrigo ◽  
...  
Keyword(s):  
International Space Station ◽  
Gamma Ray ◽  
State Of The Art ◽  
Space Station ◽  
Upper Atmosphere ◽  
International Space ◽  
Severe Thunderstorms

Atmosphere-Space Interactions Monitor (ASIM) mission is an ESA pay load which will be installed in the Columbus module of the International Space Station (ISS). ASIM is optimized to the observation and monitoring of luminescent phenomena in the upper atmosphere, the so called Transient Luminous Event (TLEs) and Terrestrial Gamma Ray Flashes(TGFs). Both TLEs and TGFs have been discovered recently (past two decades) and opened a new field of research in high energetic phenomena in the atmosphere. We will review the capabilities of ASIM and how it will help researchers to gain deeper knowledge of TGFs, TLEs, their inter-relationship and how they are linked to severe thunderstorms and the phenomena of lightning.

scholarly journals A parameterization of Long-Continuing-Current (LCC) lightning in the lightning submodel LNOX (version 3.0) of the Modular Earth Submodel System (MESSy, version 2.54)

2021 ◽  
Author(s):  
Francisco Javier Pérez-Invernón ◽  
Heidi Huntrieser ◽  
Patrick Jöckel ◽  
Francisco J. Gordillo-Vázquez
Keyword(s):  
Meteorological Data ◽  
Space Station ◽  
Low Frequency ◽  
Electrical Current ◽  
Pressure Level ◽  
Convective Precipitation ◽  
Atmospheric Models ◽  
Optical Instruments ◽  
Current Flows ◽  
Imaging Sensor

Abstract. Lightning flashes can produce a discharge in which a continuing electrical current flows for more than 40 ms. This type of flashes are proposed to be the main precursors of lightning-ignited wildfires and also to trigger sprite discharges in the mesosphere. However, lightning parameterizations implemented in global atmospheric models do not include information about the continuing electrical current of flashes. The continuing current of lightning flashes cannot be detected by conventional lightning location systems. Instead, these so-called Long-Continuing-Current (LCC) flashes are commonly observed by Extreme Low Frequency (ELF) sensors and by optical instruments located in space. Previous reports of LCC lightning flashes tend to occur in winter and oceanic thunderstorms, which suggests a connection between weak convection and the occurrence of this type of discharge. In this study, we develop a parameterization of LCC lightning flashes based on a climatology derived from optical lightning measurements reported by the Lightning Imaging Sensor (LIS) on-board the International Space Station (ISS) between March 2017 and March 2020. We use meteorological data from reanalyses to find a global parameterization that uses the vertical velocity at 450 hPa pressure level as a proxy for the ratio of LCC to typical lightning in thunderstorms. We implement this parameterization into the LNOX submodel of the Modular Earth Submodel System (MESSy) for usage within the EMAC model, and compare the observed and the simulated climatologies of LCC lightning flashes using six different lightning parameterizations. We find that the best agreement between the simulated and the observed spatial distribution is obtained when using a novel combined lightning parameterization based on the cloud top height over land and on the convective precipitation over ocean.

Comparison of novel imaging sensor and gamma ray tomography imaging of grout deficiencies in external post-tensioned structural tendons

2021 ◽  
Vol 117 ◽  
pp. 102368
Author(s):  
Hani Freij ◽  
David Dukeman ◽  
Christopher L. Alexander ◽  
Marcelo D. Ruffolo ◽  
Teresita Frigerio ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Tomography Imaging ◽  
Imaging Sensor ◽  
Post Tensioned

scholarly journals An X-Ray All Sky Monitor for a Japanese Experimental Module on the Space Station

1990 ◽  
Vol 123 ◽  
pp. 463-468
Author(s):  
M. Matsuoka ◽  
N. Kawai ◽  
T. Imai ◽  
M. Yamauchi ◽  
A. Yoshida ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Space Station ◽  
Transient Phenomena ◽  
X Ray ◽  
Sky Monitor ◽  
Image Position ◽  
Japanese Experimental Module

AbstractWe propose an X-ray all sky monitor for Japanese Experimental Module (JEM) on the space station. Considering practical circumstances, we show as a case study that the all sky monitor with slit hole cameras is most promising for monitoring the short-term and long-term X-ray transients. We call this all sky monitor as MAXI (Monitor of All-sky X-ray Image). Position determination of gamma-ray bursts could be achieved with accuracy less than one degree observing the X-ray component of the burst. Weak X-ray sources such as active galactic nuclei could be also monitored with time resolution less than one day. The X-ray all sky monitor will work to discover X-ray novae and transient phenomena and give us the alarm for further detailed observations. The obtained data will be also used for archival study.

Sign in / Sign up

Export Citation Format

Share Document