A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances
Artikel i vetenskaplig tidskrift, 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.

instability mechanisms

travelling ionospheric disturbances

Ionospheric scintillation

Författare

Richard A. Fallows

Netherlands Institute for Radio Astronomy (ASTRON)

Biagio Forte

University of Bath

Ivan Astin

University of Bath

Tom Allbrook

BAE Syst Operat Ltd

University of Bath

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

Univ Warmia & Mazury

James M. Anderson

GFZ German Res Ctr Geosci

Technische Universität Berlin

Ashish Asgekar

Shell Technol Ctr

I. Max Avruch

Sci & Technol BV

Mark Bentum

Netherlands Institute for Radio Astronomy (ASTRON)

Mario M. Bisi

Rutherford Appleton Lab

Harvey R. Butcher

Australian National University

Benedetta Ciardi

Max-Planck-Gesellschaft

Bartosz Dabrowski

Univ Warmia & Mazury

Sieds Damstra

Netherlands Institute for Radio Astronomy (ASTRON)

Francesco de Gasperin

Universität Hamburg

Sven Duscha

Netherlands Institute for Radio Astronomy (ASTRON)

Jochen Eisloeffel

Thuringer Landessternwarte

Thomas M. O. Franzen

Netherlands Institute for Radio Astronomy (ASTRON)

Michael A. Garrett

Universiteit Leiden

University of Manchester

Jean-Matthias Griessmeier

Universite d'Orleans

Andre W. Gunst

Netherlands Institute for Radio Astronomy (ASTRON)

Matthias Hoeft

Thuringer Landessternwarte

Jorg R. Horandel

Radboud Universiteit

Vrije Universiteit Brüssel (VUB)

Nikhef

Marco Iacobelli

Netherlands Institute for Radio Astronomy (ASTRON)

Huib T. Intema

Universiteit Leiden

Leon V. E. Koopmans

Rijksuniversiteit Groningen

Peter Maat

Netherlands Institute for Radio Astronomy (ASTRON)

Gottfried Mann

Leibniz Inst Astrophys Potsdam

Anna Nelles

Deutsches Elektronen-Synchrotron (DESY)

Friedrich-Alexander-Universität Erlangen Nurnberg (FAU)

Harm Paas

Rijksuniversiteit Groningen

Vishambhar N. Pandey

Rijksuniversiteit Groningen

Netherlands Institute for Radio Astronomy (ASTRON)

Wolfgang Reich

Max-Planck-Gesellschaft

Antonia Rowlinson

Universiteit Van Amsterdam

Netherlands Institute for Radio Astronomy (ASTRON)

Mark Ruiter

Netherlands Institute for Radio Astronomy (ASTRON)

Dominik J. Schwarz

Universität Bielefeld

Maciej Serylak

South African Radio Astron Observ

University of the Western Cape

Aleksander Shulevski

Universiteit Van Amsterdam

Oleg M. Smirnov

South African Radio Astron Observ

Rhodes University

Marian Soida

Uniwersytet Jagiellonski w Krakowie

Matthias Steinmetz

Leibniz Inst Astrophys Potsdam

Satyendra Thoudam

Khalifa University

Maria Carmen Toribio Perez

Chalmers, Rymd-, geo- och miljövetenskap, Onsala rymdobservatorium, Onsala rymdobservatorium, Observationssupport

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 Inst Astrophys Potsdam

Ralph A. M. J. Wijers

Universiteit Van Amsterdam

Olaf Wucknitz

Max-Planck-Gesellschaft

Philippe Zarka

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

Centre national de la recherche scientifique (CNRS)

Pietro Zucca

Netherlands Institute for Radio Astronomy (ASTRON)

Journal of Space Weather and Space Climate

2115-7251 (eISSN)

Vol. 10 10

Ämneskategorier

Astronomi, astrofysik och kosmologi

Geofysik

Fusion, plasma och rymdfysik

DOI

10.1051/swsc/2020010

Mer information

Senast uppdaterat

2020-08-28