Explanipedia

Measuring location and properties of very high frequency sources emitted from an aircraft flying through high clouds Open

O. Schölten, Marten Lourens, J. R. Dwyer, B. M. Hare, T. N. G. Trinh , et al. · 2025

While broadband short-duration radio pulses from airplanes are commonly detected and used for calibration or as background in astrophysical observations, the precise locations of the emission regions cannot be determined in these studies. …

Thunderstorm Charge Distribution Determination Using Cosmic Rays Induced Air Showers and Lightning Imaging at LOFAR Open

T. N. G. Trinh, O. Schölten, R. Van Loon, B. M. Hare, Jelle Assink , et al. · 2025

The LOw Frequency ARray (LOFAR) radio telescope possesses the unique capability to measure ultra‐high energy cosmic rays as well as image lightning discharges. This study presents a comparison between the inferred thunderstorm charge struc…

Monte Carlo Error Analysis of Lightning Interferometry with LOFAR Open

Paulina Ťureková, B. M. Hare, O. Schölten, Steven A. Cummer, J. R. Dwyer , et al. · 2024

The LOFAR radio telescope works on a principle of radio interferometric imaging. It coherently sums the signal of hundreds of antennas in northern Netherlands, covering the 30-80 MHz window of the very high frequency (VHF) band of 30-300 M…

Gamma-ray glows and terrestrial gamma-ray flashes produced by thunderstorm electrification without lightning  Open

J. R. Dwyer, Ningyu Liu · 2024

Terrestrial gamma-ray flashes (TGFs), powerful bursts of gamma-rays produced within our atmosphere, often occur in association with lightning. However, the mechanisms for generating the large number of runaway electrons required to account…

LOFAR Observations of the Initial Stage of IC Dart Leaders Open

B. M. Hare, O. Schölten, Paulina Ťureková, Steven A. Cummer, J. R. Dwyer , et al. · 2024

In previous work we have found that dart leaders quench needle activity; where dart leaders are charge pulses that re-trace previously established lightning leader channels, and needles are small repeating negative discharges that propagat…

Two Laterally Distant TGFs From Negative Cloud‐To‐Ground Strokes in Uchinada, Japan Open

John Ortberg, David M. Smith, Masashi Kamogawa, J. R. Dwyer, G. S. Bowers , et al. · 2024

We observed two Terrestrial Gamma‐ray Flashes (TGFs) in Uchinada, Japan associated with negative cloud‐to‐ground lightning strokes exactly 1 year apart on 18 December 2020 and 2021. The events were remarkable for their lateral distance fro…

Searching for intra-cloud positive leaders in VHF Open

O. Schölten, B. M. Hare, J. R. Dwyer, Ningyu Liu, C. Sterpka , et al. · 2023

VHF emitting width and 3D polarization of lightning dart leaders Open

B. M. Hare, O. Schölten, S. Buitink, J. R. Dwyer, Ningyu Liu , et al. · 2023

After the lightning initial stage, lightning flash plasma channels (leaders) can become unstable and exhibit current pulses called dart leaders that propagate back down the lightning channel. These pulses are difficult to understand as the…

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory Open

Roberta Colalillo, J. R. Dwyer, Adila Abdul Halim, P. Abreu, M. Aglietta , et al. · 2023

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique…

A Strong Pulsing Nature of Negative Intracloud Dart Leaders Accompanied by Regular Trains of Microsecond‐Scale Pulses Open

Ivana Kolmašová, O. Schölten, O. Santolı́k, B. M. Hare, Petr Zacharov , et al. · 2023

We report the first observations of negative intracloud (IC) dart‐stepped leaders accompanied by regular trains of microsecond‐scale pulses, simultaneously detected by shielded broadband magnetic loop antennas and the radio telescope Low F…

Small‐Scale Discharges Observed Near the Top of a Thunderstorm Open

O. Schölten, B. M. Hare, J. R. Dwyer, Ningyu Liu, C. Sterpka , et al. · 2023

We have used the LOw‐Frequency ARray (LOFAR) to image a few lightning flashes during a particularly severe thunderstorm. The images show an exceptional amount of VHF activity at altitudes above 10 km. Much of this is in the form of small‐s…

Searching for intra-cloud positive leaders in VHF Open

O. Schölten, B. M. Hare, J. R. Dwyer, Ningyu Liu, C. Sterpka , et al. · 2023

We have used the LOw-Frequency ARray (LOFAR) to search for the growing tip of an intra-cloud (IC) positive leader. Even with our most sensitive beamforming method, where we coherently add the signals of about 170 antenna pairs, we were not…

The propagation and 3D VHF polarization properties of recoil leaders Open

B. M. Hare, O. Schölten, S. Buitink, J. R. Dwyer, Ningyu Liu , et al. · 2023

Lightning dart and recoil leaders are difficult to understand, as they have a different (often smoother) propagation mode than stepped leaders, and re-ionize a previously ionized channel. In order to understand them better, we have imaged …

Studying downward TGFs with the largest ground array of gamma-ray detectors Open

Roberta Colalillo, J. R. Dwyer, David M. Smith, John Ortberg · 2023

The Pierre Auger Observatory, the largest cosmic-ray detector in the world, has beenobserving peculiar events which are very likely downward TGFs. Their experimentalsignature and their time evolution are very different from those of a show…

A strong pulsing nature of negative recoil leaders accompanied by regular trains of microsecond-scale pulses Open

Ivana Kolmašová, O. Schölten, O. Santolı́k, B. M. Hare, Ningyu Liu , et al. · 2023

A presence of regular sequences of microsecond-scale pulses has been occasionally reported in the lightning literature for more than forty years. Due to a fine time resolution of modern electromagnetic receivers, the properties of these pu…

Characteristics of recoil leaders as observed by LOFAR Open

B. M. Hare, O. Schölten, S. Buitink, J. R. Dwyer, Ningyu Liu , et al. · 2023

\n Contains fulltext :\n 289944.pdf (Publisher’s version ) (Open Access)\n

Ultra‐Slow Discharges That Precede Lightning Initiation Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, Nicholas Demers, B. M. Hare , et al. · 2022

We report on ultra‐slowly propagating discharge events with speeds in the range 1–13 km/s, much lower than any known lightning process. The propagation speeds of these discharges are orders of magnitude slower than leader or streamer speed…

Ultra-Slow Discharges that Precede Lightning Initiation dataset Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, Nicholas Demers, B. M. Hare , et al. · 2022

Description of Dataset: These data were used to produce figures for the Geophysical Research Letters publication: Ultra-Slow Discharges that Precede Lightning Initiation. Data are provided in human readable ".csv"…

Ultra-Slow Discharges that Precede Lightning Initiation dataset Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, Nicholas Demers, B. M. Hare , et al. · 2022

Description of Dataset: These data were used to produce figures for the Geophysical Research Letters publication: Ultra-Slow Discharges that Precede Lightning Initiation. Data are provided in human readable ".csv"…

Ultra-Slow Discharges That Precede Lightning Initiation Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, Nicholas Demers, B. M. Hare , et al. · 2022

We report on ultra-slowly propagating discharge events with speeds in the range 1-13 km/s, much lower than any known lightning process. The propagation speeds of these discharges are orders of magnitude slower than leader or streamer speed…

Small-scale discharges observed near the top of a thunderstorm Open

O. Schölten, B. M. Hare, J. R. Dwyer, Ningyu Liu, C. Sterpka , et al. · 2022

We have used the LOw-Frequency ARray (LOFAR) to image a few lightning flashes during a particularly severe thunderstorm. The images show an exceptional amount of VHF activity at altitudes above 10 km. Much of this is in the form of small-s…

Implications of Multiple Corona Bursts in Lightning Processes for Radio Frequency Interferometer Observations Open

Ningyu Liu, O. Schölten, J. R. Dwyer, B. M. Hare, C. Sterpka , et al. · 2022

Recent observations from LOFAR indicate that multiple, spatially distributed corona bursts can occur in lightning processes with a timescale of 10 microseconds. The close proximity of the corona bursts in space and time poses a great obser…

The hidden power of lightning: studying the most explosive events in thunderstorms with the world’s largest cosmic-ray observatory Open

Roberta Colalillo, J. R. Dwyer · 2022

The Pierre Auger Observatory, designed to study ultra-high energy cosmic rays, has accidentally observed, with its 3000 km2 surface array of water-Cherenkov detectors, several events that are very likely dow…

Uncharacteristically Slow Discharge Process Observed Preceding Lightning Initiation Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, Nicholas Demers, B. M. Hare , et al. · 2022

In continuation of the study reported last year, we report additional results from imaging lightning initiation via interferometric beamforming of data collected by the Dutch LOw Frequency ARray (LOFAR).  Significant impr…

The 3D Polarization of Recoil Leaders Open

B. M. Hare, O. Schölten, J. R. Dwyer, Ningyu Liu, Chris Strepka , et al. · 2022

We have recently developed a new 3D beamforming algorithm, using data from the LOw Frequency ARray (LOFAR) radio telescope (in the 30-80 MHz band), that is capable of resolving even the most complex lightning phenomena with meter …

Interferometric imaging of intensely radiating negative leaders Open

O. Schölten, B. M. Hare, J. R. Dwyer, Ningyu Liu, C. Sterpka , et al. · 2022

The common phenomenon of lightning still harbors many secrets and only recently a new propagation mode was observed for negative leaders. While propagating in this “intensely radiating negative leader” (IRNL) mode a negative leader emits 1…

LOFAR Observations of Lightning Initial Breakdown Pulses Open

Ningyu Liu, O. Schölten, B. M. Hare, J. R. Dwyer, C. Sterpka , et al. · 2022

This paper reports an observational study of lightning initial breakdown pulses (IBPs) using the low‐frequency array radio telescope and a broadband magnetic field sensor. The data show that the overall spatiotemporal evolution of the elec…

Implications of Multiple Corona Bursts in Lightning Processes for Radio Frequency Interferometer Observations Open

Ningyu Liu, O. Schölten, J. R. Dwyer, B. M. Hare, C. Sterpka , et al. · 2021

Earth and Space Science Open Archive This work has been accepted for publication in Geophysical Research Letters. Version of RecordESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary. Learn mor…

The Spontaneous Nature of Lightning Initiation Revealed Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, B. M. Hare, O. Schölten , et al. · 2021

Earth and Space Science Open Archive This work has been accepted for publication in Geophysical Research Letters. Version of RecordESSOAr is a venue for early communication or feedback before peer review. Data may be preliminary. Learn mor…

The Spontaneous Nature of Lightning Initiation Revealed Open

C. Sterpka, J. R. Dwyer, Ningyu Liu, B. M. Hare, O. Schölten , et al. · 2021

Here, we present new radio interferometer beamforming observations of lightning initiation using data from the Low‐Frequency Array (LOFAR). We show that the first lightning source in the flash increases exponentially in intensity by two or…

J. R. Dwyer YOU? Author Swipe