A5079436560- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Earthquake Detection and Analysis
- GNSS positioning and interference
- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Stellar, planetary, and galactic studies
- Radio Astronomy Observations and Technology
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Planetary Science and Exploration
- Seismic Waves and Analysis
- earthquake and tectonic studies
- History and Developments in Astronomy
- Space exploration and regulation
- Historical Geography and Cartography
- Geophysical and Geoelectrical Methods
- Seismology and Earthquake Studies
- Advanced Electrical Measurement Techniques
- Non-Destructive Testing Techniques
- Media, Religion, Digital Communication
- Generational Differences and Trends
- Solar Radiation and Photovoltaics
University of Birmingham
2020-2024
Netherlands Institute for Radio Astronomy
2023
Nottingham Trent University
2019-2020
National Observatory of Athens
2012
Queen's University Belfast
2010
Aberystwyth University
2007-2009
Czech Academy of Sciences, Institute of Mathematics
2008
University of Wales
2007
Abstract The high latitude ionospheric evolution of the May 10‐11, 2024, geomagnetic storm is investigated in terms Total Electron Content and contextualized with Incoherent Scatter Radar ionosonde observations. Substantial plasma lifting observed within initial Storm Enhanced Density plume peak heights increasing by 150–300 km, reaching levels up to 630 km. Scintillation cusp during expansion phase storm, spreading across auroral oval thereafter. Patch transport into polar cap produces...
The Low Frequency Array (LOFAR) is one of the most advanced radio telescopes in world. When waves from a distant astronomical source pass through Earth’s upper atmosphere, plasma structures act as lenses. refraction these waves, and their subsequent interference, significantly affects received signal. Activities have been developed for secondary school students aged between 16-18 based on observations.Students are given research data LOFAR work groups to interpret observations,...
The 2022 Hunga Tonga Volcano Eruption (HTVE) had unprecedented impacts on atmospheric space weather. It provided a clear example of how weather may be impacted by influences both “from above” (e.g. the solar wind, geo-magnetic storms) and below” powerful volcanoes, hurricanes, earthquakes). Manifestations geophysical effects from HTVE were an acoustic wave that circled Earth several times, formation strong ionospheric plasma bubbles depletion. An important...
A number of recent investigations have revealed that transverse waves are ubiquitous in the solar chromosphere. The vast majority these been reported limb spicules and active region fibrils. We investigate long-lived, quiet-Sun, on-disk features such as chromospheric mottles (jet-like located at boundaries supergranular cells) their motions. observations were obtained with Rapid Oscillations Solar Atmosphere instrument Dunn Telescope. data set is comprised simultaneous imaging Hα core, Ca ii...
A climatology of Travelling Ionospheric Disturbances (TIDs) observed using the LOw Frequency ARray (LOFAR) has been created based on 2,723 hours astronomical observations. Radio telescopes such as LOFAR must contend with many causes signal distortions, including ionosphere. To produce accurate images, calibration solutions are derived to mitigate these distortions much possible. These provide extremely precise measurements ionospheric variations across network, enabling TIDs be detected...
The Low Frequency Array (LOFAR) is one of the most advanced radio telescopes in world. When waves from a distant astronomical source traverse ionosphere, structures this plasma affect signal. high temporal resolution available (~10 ms), range frequencies observed (10-90 MHz & 110-250 MHz) and large number receiving stations (currently 52 across Europe) mean that LOFAR can also observe effects midlatitude sub-auroral ionosphere at an unprecedented level detail.Case studies have shown...
Abstract Swarm is the first European Space Agency (ESA) constellation mission for Earth Observation. Three identical satellites were launched into near-polar orbits on 22 November 2013. Each satellite hosts a range of instruments, including Langmuir probe, GPS receivers, and magnetometers, from which ionospheric plasma can be sampled current systems inferred. In March 2018, CASSIOPE/e-POP was formally integrated through ESA’s Earthnet Third Party Mission Programme. Collectively instruments...
This paper presents the results from one of first observations ionospheric scintillation taken using Low-Frequency Array (LOFAR). The observation was strong natural radio source Cassiopeia A, overnight on 18–19 August 2013, and exhibited moderately scattering effects in dynamic spectra intensity received across an observing bandwidth 10–80 MHz. Delay-Doppler (the 2-D FFT spectrum) hour showed two discrete parabolic arcs, with a steep curvature other shallow, which can be used to provide...
Statistical models of the variability plasma in topside ionosphere based on Swarm data have been developed “Swarm Variability Ionospheric Plasma” (Swarm-VIP) project within European Space Agency’s Swarm+4D-Ionosphere framework. The can predict electron density, its gradients for three horizontal spatial scales – 20, 50 and 100 km along North-South direction level density fluctuations. Despite being by leveraging data, provide predictions that are independent these having a global coverage,...
Observations made using the LOw-Frequency ARray (LOFAR) between 10:15 and 11:48 UT on 15th of September 2018 over a bandwidth approximately 25–65 MHz contain discrete pseudo-periodic features ionospheric origin. These occur within period 10 min collectively last roughly an hour. They are strongly frequency dependent, broadening significantly in time towards lower frequencies, show overlaid pattern diffraction fringes. By modelling ionosphere as thin phase screen containing wave-like...
Occasionally, large solar energetic particle (SEP) events occur inside magnetic clouds (MCs). In this work, the onset time analysis, peak intensity and decay phase analysis of SEPs are used to investigate two SEP MCs: 1998 May 2 2002 April 21 events. The non-relativistic electrons ∼MeV nucleon−1 heavy ions shows stability loop structure during a period few hours in examined. joint pitch-angle distributions intensities exhibits that, depending on pitch angle observed at 1 AU, event reflection...
Abstract The large scale morphology and finer sub‐structure within a slowly propagating traveling ionospheric disturbance (TID) are studied using wide band trans‐ionospheric radio observations with the LOw Frequency ARray (LOFAR; van Haarlem et al., 2013, https://doi.org/10.1051/0004-6361/201220873 ). were made under geomagnetically quiet conditions, between 0400 0800 on 7 January 2019, over UK. In combination ionograms Global Navigation Satellite System Total Electron Content anomaly data...
This work presents statistical models of the variability plasma in topside ionosphere based on observations made by European Space Agency’s (ESA) Swarm satellites. The were developed “Swarm Variability Ionospheric Plasma” (Swarm-VIP) project within Swarm+4D-Ionosphere framework. configuration satellites, their near-polar orbits and data products developed, enable studies spatial at multiple scale sizes. modelling technique Generalised Linear Modelling (GLM) was used to create both electron...
Abstract Radio interferometers used to make astronomical observations, such as the LOw Frequency ARray (LOFAR), experience distortions imposed upon received signal due ionosphere well those from instrumental errors. Calibration using a well‐characterized radio source can be mitigate these effects and produce more accurate images of sources, calibration process provides measurements ionospheric conditions over wide range length scales. The basic measurement this is differential Total Electron...
Abstract. The antennas of EISCAT have been used for interplanetary scintillation (IPS) studies the solar wind many years. main science found from these is obtained through cross-correlation signals having longest baseline, providing more accurate information on different streams which may be present in line sight. development dual-frequency IPS observations between 1.4 GHz receivers at remote sites and Tromsø, has allowed use Svalbard Radar IPS, increasing available baselines to extent that...
The European Incoherent SCATter (EISCAT) radar has been used for remote-sensing observations of interplanetary scintillation (IPS) a quarter century. During the April/May 2007 observing campaign, large number IPS using EISCAT took place to give reasonable spatial and temporal coverage solar wind velocity structure throughout this time during declining phase Solar Cycle 23. Many co-rotating transient features were observed period. Using University California, San Diego three-dimensional (3-D)...
Long-baseline observations of interplanetary scintillation (IPS) provide a unique source information on solar wind speed and meridional direction across the inner regions system. We report results series coordinated IPS an Earth-directed CME. A significant development in interpretation these data is use 3D tomographic reconstructions structure derived from STELab to better constrain analysis extremely long baseline EISCAT MERLIN. The combination two approaches leads significantly...
We describe simultaneous Interplanetary Scintillation (IPS) and STEREO Heliospheric Imager (HI) observations of a coronal mass ejection (CME) on 16 May 2007. Strong CME signatures were present throughout the IPS observation. The raypath lay within field‐of‐view HI‐1 STEREO‐A comparison shows that measurements came from region faint front observed by HI‐1A. This may represent merging two converging CMEs. Plane‐of‐sky velocity estimates based time‐height plots structures 325 kms −1 550 for...