A5036469555- Ionosphere and magnetosphere dynamics
- Earthquake Detection and Analysis
- Solar and Space Plasma Dynamics
- GNSS positioning and interference
- Geomagnetism and Paleomagnetism Studies
- Geophysics and Gravity Measurements
- Plasma Diagnostics and Applications
- Magnetic confinement fusion research
- Seismic Waves and Analysis
- Atmospheric Ozone and Climate
- Radar Systems and Signal Processing
- Astro and Planetary Science
- Radio Astronomy Observations and Technology
- Radio Wave Propagation Studies
- Dust and Plasma Wave Phenomena
- Electromagnetic Scattering and Analysis
- Electromagnetic Compatibility and Measurements
- Particle accelerators and beam dynamics
- Laser-induced spectroscopy and plasma
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Geophysics and Sensor Technology
- Ocean Waves and Remote Sensing
- Meteorological Phenomena and Simulations
- Advanced SAR Imaging Techniques
- Spacecraft and Cryogenic Technologies
European Incoherent Scatter Scientific Association
2015-2024
UiT The Arctic University of Norway
2013-2022
European Incoherent Scatter Scientific Association
2005-2016
Lancaster University
2013
Lancaster University Ghana
2013
University of Leicester
2013
Max Planck Society
1996-2006
Max Planck Institute for Solar System Research
1996-2006
Max Planck Institute for Astronomy
1997-2003
Experimental results, obtained with the Heating facility and EISCAT UHF VHF radars at Tromsø, Norway, have been used to test existing Langmuir turbulence theories provide further observational facts be taken into account in a new theoretical formulation of turbulence. It is found that none available able describe diversity facts. The dominance propagating ion acoustic waves observed spectra, fact these closely follow their linear dispersion relations, lend support weak description. On other...
Abstract The high‐power HF (high‐frequency) facility (commonly known as Heating) near Tromsø, Norway, which is an essential part of the European Incoherent Scatter Scientific Association, has been upgraded in certain key areas recent years. It one only four similar facilities world operating at present. An updated description given, together with scientific motivation and some results. main parts such transmitters, feed‐system, antennas remain essentially same built late 1970s. improvements...
In this paper we study how GPS, GLONASS, and Galileo navigation signals are compromised by strong irregularities causing severe phase scintillation ($\mathit{\sigma }_{\phi }$ > 1) in the nightside high-latitude ionosphere during a substorm on 3 November 2013. Substorm onset later intensification coincided with polar cap patches entering auroral oval to become blobs. Using Global Navigation Satellite Systems (GNSS) receivers optical data, show driven intense emissions line of sight between...
A coordinated experiment involving ionospheric heating and VHF observations of polar mesosphere summer echoes (PMSE) has recently been conducted at the EISCAT facility near Tromsø, Norway. We have demonstrated for first time that can influence radar returns associated with PMSE. Artificially elevating electron temperatures within PMSE layer shown to reduce echo power. Based on this other results from experiment, it is suggested observed reduction in power related an enhancement diffusivity...
This report presents the first estimates of three‐dimensional volume emission rate enhanced O ( 1 D) 6300 Å airglow caused by HF radio wave pumping in ionosphere. Images excitation show how initially speckled spatial structure changes to a simpler shape with smaller region that contains most excitation. A was imaged three stations Auroral Large Imaging System (ALIS) northern Scandinavia. These images allowed for tomography‐like inversion airglow. The altitude maximum found be around 235 ± 5...
We present results of the local field strength and, for first time, apparent source height as a function frequency from 200 to 6600 Hz ELF/VLF waves produced in auroral D region through modulated RF heating using ionospheric facility near Tromsø, Norway. These data show, besides normal amplitude peaks 2, 4, and 6 kHz, occasional presence at intermediate frequencies, especially right‐hand circularly polarized mode. A comprehensive model has been developed explain data, full wave solution by...
[1] The effects on the high-latitude F region of ionosphere by X-mode powerful HF radio waves injected towards magnetic zenith (MZ) are analysed. The experiments were conducted using EISCAT/Heating facility and UHF radar at Tromso, Norway, CUTLASS (SuperDARN) EISCAT ionosonde (dynasonde). results show that pump wave, radiated into from heater, can generate very strong small-scale artificial field aligned irregularities (AFAIs) in F-region ionosphere. These irregularities, with spatial scales...
Measurements of plasma and ion lines induced during HF ionospheric interaction experiments have been made with the European Incoherent Scatter (EISCAT) facility at Tromsø sufficiently high‐altitude resolution to compare theories Langmuir turbulence. Recent turbulence models predict a change from broad structureless spectra line or cascade within few hundred meters for VHF (224 MHz) observations assuming typical density gradients. In campaign in May 1994 we found that were grouped into two...
Radio waves at frequencies between 525 and 5850 Hz were observed simultaneously on the ground in VLF receiver of ISIS 1 spacecraft during a flight over Max‐Planck‐Institut für Aeronomie ionospheric heater near Tromsø, Norway, December 9, 1981. The carrier frequency, 4.04 MHz, was amplitude modulated with set four frequencies: 525, 1725, 2925, 4125 Hz. satellite detected all these fundamental plus harmonics 2925 components, caused by nonsinusoidal modulation carrier. Characteristics signal...
In October 1981, ELF/VLF waves were produced in the ionosphere an alternating sequence of approximately 1, 2, 3, and 5 kHz by modulated HF heating near Tromsø, Norway, during a 32‐hour period high geomagnetic disturbance. The apparent source heights, which are derived from wave phases, show diurnal variation about 55 km day to 74 at night. Other parameters such as amplitude, direction, ellipticity ELF polarization ellipse also well modulation Pc hydromagnetic waves. We compare with electric...
Simultaneous observations by up to three low‐light imaging stations belonging the Auroral Large Imaging System (ALIS) have provided first strong evidence of high‐frequency (HF) pump‐enhanced airglow at auroral latitudes. The was enhanced an ordinary mode 4.04 MHz electromagnetic wave with effective radiated power (ERP) about 210 MW that transmitted from EISCAT‐Heating facility near Tromsø, Norway. While often observed low or mid‐latitudes, and despite numerous earlier experiments, no...
Abstract. The shape of the electron energy distribution has long been a central question in field high-frequency radio-induced optical emission experiments. This report presents estimates function, fe(E), from 0 to 60 eV, based on multi-wavelength (6300, 5577, 8446, 4278Å) data and 930-MHz incoherent scatter radar measurements ion temperature, temperature concentration. According our estimate, depression at around 2 probably caused by excitation vibrational states N2, high tail that is...
Abstract. Observations of secondary radiation, stimulated electromagnetic emission (SEE), produced during ionospheric modification experiments using ground-based, high-power, high-frequency (HF) radio waves are considered. The High Frequency Active Auroral Research Program (HAARP) facility is capable generating narrowband SEE in the form Brillouin scatter (SBS) and ion Bernstein (SIBS) spectrum. Such spectral lines have not been reported European Incoherent Scatter (EISCAT) heater before....
Abstract. The ESRAD 52-MHz and the EISCAT 224-MHz radars in northern Scandinavia observed thin layers of strongly enhanced radar echoes from mesosphere (Polar Mesosphere Winter Echoes - PMWE) during a solar proton event November 2004. Using interferometric capabilities it was found that scatterers responsible for PMWE show very high horizontal travel speeds, up to 500 ms-1 or more, aspect sensitivity, with echo arrival angles spread over as little 0.3°. also detected, on some occasions,...
At Skibotn in northern Norway, measurements have been made of the effect powerful HF waves, from heating facility at Ramfjordmoen, on propagation VLF waves Omega transmitter (12.1 kHz) near Aldra and 16.4‐kHz transmissions (JXN) Helgeland. The beam was deflectable a north‐south direction, which enabled it to intersect path. amplitude phase perturbations were found oscillate about zero as scanned across path, typical daytime had maximum magnitudes ∼0.1 dB 0.5°. values appeared when heated...