A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances
Journal article, 2020

This paper presents the results from one of the first observations of ionospheric scintillation taken using the Low-Frequency Array (LOFAR). The observation was of the strong natural radio source Cassiopeia A, taken overnight on 18-19 August 2013, and exhibited moderately strong scattering effects in dynamic spectra of intensity received across an observing bandwidth of 10-80 MHz. Delay-Doppler spectra (the 2-D FFT of the dynamic spectrum) from the first hour of observation showed two discrete parabolic arcs, one with a steep curvature and the other shallow, which can be used to provide estimates of the distance to, and velocity of, the scattering plasma. A cross-correlation analysis of data received by the dense array of stations in the LOFAR "core" reveals two different velocities in the scintillation pattern: a primary velocity of similar to 20-40 ms(-1) with a north-west to south-east direction, associated with the steep parabolic arc and a scattering altitude in the F-region or higher, and a secondary velocity of similar to 110 ms(-1) with a north-east to south-west direction, associated with the shallow arc and a scattering altitude in the D-region. Geomagnetic activity was low in the mid-latitudes at the time, but a weak sub-storm at high latitudes reached its peak at the start of the observation. An analysis of Global Navigation Satellite Systems (GNSS) and ionosonde data from the time reveals a larger-scale travelling ionospheric disturbance (TID), possibly the result of the high-latitude activity, travelling in the north-west to south-east direction, and, simultaneously, a smaller-scale TID travelling in a north-east to south-west direction, which could be associated with atmospheric gravity wave activity. The LOFAR observation shows scattering from both TIDs, at different altitudes and propagating in different directions. To the best of our knowledge this is the first time that such a phenomenon has been reported.

travelling ionospheric disturbances

Ionospheric scintillation

instability mechanisms

Author

Richard A. Fallows

Netherlands Institute for Radio Astronomy (ASTRON)

Biagio Forte

University of Bath

Ivan Astin

University of Bath

Tom Allbrook

University of Bath

Bae Systems (Operation) Ltd

Alex Arnold

University of Bath

Alan Wood

Nottingham Trent University

Gareth Dorrian

University of Birmingham

Maaijke Mevius

Netherlands Institute for Radio Astronomy (ASTRON)

Hanna Rothkaehl

Polish Academy of Sciences

Barbara Matyjasiak

Polish Academy of Sciences

Andrzej Krankowski

University of Warmia and Mazury in Olsztyn

James M. Anderson

Technische Universität Berlin

German Research Centre for Geosciences (GFZ)

Ashish Asgekar

Shell Technology Center

I. Max Avruch

Sci & Technol BV

Mark Bentum

Netherlands Institute for Radio Astronomy (ASTRON)

Mario M. Bisi

STFC Rutherford Appleton Laboratory

Harvey R. Butcher

Australian National University

Benedetta Ciardi

Max Planck Society

Bartosz Dabrowski

University of Warmia and Mazury in Olsztyn

Sieds Damstra

Netherlands Institute for Radio Astronomy (ASTRON)

Francesco de Gasperin

University of Hamburg

Sven Duscha

Netherlands Institute for Radio Astronomy (ASTRON)

Jochen Eisloeffel

Thüringer Landessternwarte Tautenburg

Thomas M. O. Franzen

Netherlands Institute for Radio Astronomy (ASTRON)

Michael A. Garrett

University of Manchester

Leiden University

Jean-Matthias Griessmeier

University of Orléans

Andre W. Gunst

Netherlands Institute for Radio Astronomy (ASTRON)

Matthias Hoeft

Thüringer Landessternwarte Tautenburg

Jorg R. Horandel

Nikhef

Radboud University

Vrije Universiteit Brussel (VUB)

Marco Iacobelli

Netherlands Institute for Radio Astronomy (ASTRON)

Huib T. Intema

Leiden University

Leon V. E. Koopmans

University of Groningen

Peter Maat

Netherlands Institute for Radio Astronomy (ASTRON)

Gottfried Mann

Leibniz Institute for Astrophysics Potsdam

Anna Nelles

University of Erlangen-Nuremberg (FAU)

Deutsches Elektronen-Synchrotron (DESY)

Harm Paas

University of Groningen

Vishambhar N. Pandey

University of Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

Wolfgang Reich

Max Planck Society

Antonia Rowlinson

University of Amsterdam

Netherlands Institute for Radio Astronomy (ASTRON)

Mark Ruiter

Netherlands Institute for Radio Astronomy (ASTRON)

Dominik J. Schwarz

Bielefeld University

Maciej Serylak

South African Radio Astronomy Observatory (SARAO)

University of the Western Cape

Aleksander Shulevski

University of Amsterdam

Oleg M. Smirnov

South African Radio Astronomy Observatory (SARAO)

Rhodes University

Marian Soida

Jagiellonian University in Kraków

Matthias Steinmetz

Leibniz Institute for Astrophysics Potsdam

Satyendra Thoudam

Khalifa University

Maria Carmen Toribio Perez

Chalmers, Space, Earth and Environment, Onsala Space Observatory, Observation Support

Arnold van Ardenne

Netherlands Institute for Radio Astronomy (ASTRON)

Ilse M. van Bemmel

Joint Institute for VLBI in Europe (JIVE)

Matthijs H. D. van der Wiel

Netherlands Institute for Radio Astronomy (ASTRON)

Michiel P. van Haarlem

Netherlands Institute for Radio Astronomy (ASTRON)

Rene C. Vermeulen

Netherlands Institute for Radio Astronomy (ASTRON)

Christian Vocks

Leibniz Institute for Astrophysics Potsdam

Ralph A. M. J. Wijers

University of Amsterdam

Olaf Wucknitz

Max Planck Society

Philippe Zarka

Centre national de la recherche scientifique (CNRS)

LESIA - Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique

Pietro Zucca

Netherlands Institute for Radio Astronomy (ASTRON)

Journal of Space Weather and Space Climate

2115-7251 (eISSN)

Vol. 10 10

Subject Categories

Astronomy, Astrophysics and Cosmology

Geophysics

Fusion, Plasma and Space Physics

DOI

10.1051/swsc/2020010

More information

Latest update

7/9/2021 1