M. Passas

• Spanish National Research Council

Optical emissions associated with Terrestrial Gamma ray Flashes (TGFs) have recently become important subjects in space‐based and ground‐based observations as they can help us understand how TGFs are produced during thunderstorms. In this paper, we present the first time‐resolved leader spectra of the optical component associated with a downward TG...

Context. GRB 221009A, initially detected as an X-ray transient by Swift , was later revealed to have triggered the Fermi satellite about an hour earlier, marking it as a post-peak observation of the event’s emission. This GRB distinguished itself as the brightest ever recorded, presenting an unparalleled opportunity to probe the complexities of GRB...

Mesospheric Green emissions from excited Oxygen in Sprite Tops (ghosts) are infrequent and faint greenish transient luminous events that remain for hundreds of milliseconds on top of certain energetic sprites. The main hypothesis to explain this glow persistence is the long lifetime of excited atomic oxygen at 557.73 nm, a well-known emission line...

This study presents experimental results for the radial and temporal variation of neutral and ion spectroscopic signatures emerging from the heated channel of lightning‐like discharges diagnosed with a high speed (900,000 fps) imaging spectrograph. Light emissions emanate from three regions: an inner core (up to ∼2 mm), an external sheath (up to ∼4...

We present spectroscopic diagnostic methods that allow us to estimate the gas and the electron temperature in emerged lightning stroke channels (from thunderclouds) observed by the photometers and cameras of the Atmosphere Space Interaction Monitor (ASIM). We identify the species (molecules, atoms and ions) producing light emission in different wav...

High speed spectra (between ∼380 nm and ∼800 nm) of meter‐long lightning‐like discharges recorded at 672,000 fps and 1,400,000 fps (with 1.488 and 0.714 μs time resolutions and 160 ns exposure time) show optical emissions of neutral hydrogen, singly ionized nitrogen, oxygen, and doubly ionized nitrogen which are similar to those found in natural li...

Plain Language Summary Lightning are extremely rapid and violent atmospheric electricity events taking place inside thunderclouds and between thunderclouds and the ground. Investigation of the fundamental properties of different types of lightning and lightning leaders can help to deepen our understanding on lightning propagation dynamics (stepping...

We present the main parameters, design features, and optical characterization of the GrAnada LIghtning Ultrafast Spectrograph (GALIUS): a portable, ground-based spectrographic system intended for analysis of the spectroscopic signature of lightning. It has been designed to measure the spectra of the light emitted from natural and triggered lightnin...

We present the first high spectral resolution (0.24 nm) spectra of sprites. These spectra were recorded in Europe in the summers and falls of 2015 and 2016 and during January 2017. The use of high spectral resolution has allowed us to resolve for the first time the internal (vibrorotational) structure of the sprite molecular N2 first positive syste...

We present the main parameters, design features, and optical characterization of the Granada Sprite Spectrograph and Polarimeter (GRASSP), a ground-based spectrographic system intended for the analysis of the spectroscopic signature of transient luminous events (TLEs) occurring in the mesosphere of the Earth. It has been designed to measure the spe...

The emission spectrum of a meteor was recorded by the GRASSP instrument during the observation of transient luminous events (TLEs) on 2014 October 16th. The spectroscopic signal was recorded in the wavelength range from 700 to 800 nm, where the emission from atmospheric oxygen and nitrogen dominated. The good spectral resolution of the spectrum (0....

Sprites and halos are two types of the so-called transient luminous events occurring in the upper layers (40-90 km) of the earth atmosphere. Their spectacular appearance is due to the optical emissions from mesospheric plasmas caused by the electric breakdown of the high-altitude rarified air. While halos look like flattened diffuse flashes of ligh...

Laboratory low pressure (0.1 mbar ≤ p ≤ 2 mbar) glow air discharges are studied by optical emission spectroscopy to discuss several spectroscopic techniques that could be implemented by field spectrographs, depending on the available spectra resolution, to experimentally quantify the gas temperature associated with Transient Luminous Events (TLEs)...

We have studied laboratory low pressure (0.1 mbar � p � 2 mbar) glow air discharges by optical emission spectroscopy to discuss several spectroscopic techniques that could be implemented by field spectrographs, depending on the available spectral resolution, to experimentally quantify the gas temperature associated to transient luminous events (TLE...

Transient luminous events (TLEs) are short optical emissions that occur in the upper atmosphere above storm systems. They appear between 15 and 90 km altitude and last between less than a millisecond to up to two seconds. So far there are no polarization studies of TLEs, nor high-resolution spectroscopy results which could help us to understand the...

The work of Grid Group of the Institute of Astrophysics of Andalucia (IAA) is mainly focused in software simulations, data analysis observatories or image filtering.We have noticed that Grid users think that this infrastructure is very difficult to use and it is not 100% safe because of its heterogeneity. Users must know many command lines and how...

Combined measurements of high-speed camera images and reciprocating Langmuir probes have been used to characterize coherent structures in SLPM plasmas. It is common to find two intermittent structures in Argon plasmas separated approximately 10 mm one from each other, with a rotation angle of about 150°, radially opposite from the plasma centre. Ne...

Fluctuations of parallel flows, electron density and plasma potencial radial profiles have been investigated in the SLPM-upgrade. First results in SLPM-up are quite similar to those obtained in the former device. A non-gaussian character is also found in fluctuation-induced particle flux statistics. Preliminary results show non-similarity of PDF(ΓE...