A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances

Fallows RA, Forte B, Astin I, Allbrook T, Arnold A, Wood A, Dorrian G, Mevius M, Rothkaehl H, Matyjasiak B, Krankowski A, Anderson JM, Asgekar A, Avruch IM, Bentum M, Bisi MM, Butcher HR, Ciardi B, Dabrowski B, Damstra S, De Gasperin F, Duscha S, Eisloeffel J, Franzen TMO, Garrett MA, Griessmeier JM, Gunst AW, Hoeft M, Horandel JR, Iacobelli M, Intema HT, Koopmans LVE, Maat P, Mann G, Nelles A, Paas H, Pandey VN, Reich W, Rowlinson A, Ruiter M, Schwarz DJ, Serylak M, Shulevski A, Smirnov OM, Soida M, Steinmetz M, Thoudam S, Toribio MC, Van Ardenne A, Van Bemmel IM, Van Der Wiel MHD, Van Haarlem MP, Vermeulen RC, Vocks C, Wijers RAMJ, Wucknitz O, Zarka P, Zucca P (2020)

Publication Type: Journal article

Publication year: 2020

Journal

Book Volume: 10

DOI: 10.1051/swsc/2020010

Abstract

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.

Authors with CRIS profile

Involved external institutions

Shell Netherlands (NL) Astron Netherlands (NL) University of Groningen / Rijksuniversiteit Groningen Netherlands (NL) Khalifa University of Science, Technology & Research (KUSTAR) / جامعة خليفة United Arab Emirates (AE) University of Amsterdam Netherlands (NL) South African Radio Astronomy Observatory (SARAO) South Africa (ZA) Max-Planck-Institut für Radioastronomie / Max Planck Institute for Radio Astronomy Germany (DE) Jagiellonian University / Uniwersytet Jagielloński (UJ) Poland (PL) Universität Bielefeld Germany (DE) Leibniz Institute for Astrophysics Potsdam / Leibniz-Institut für Astrophysik Potsdam Germany (DE) University of Warmia and Mazury in Olsztyn Poland (PL) Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. (MPG) / Max Planck Society for the Advancement of Science Germany (DE) University of Birmingham United Kingdom (GB) Joint Institute for VLBI in Europe (JIVE) Netherlands (NL) University of Bath United Kingdom (GB) Science [&] Technology Corporation B.V. Netherlands (NL) Polska Akademia Nauk (PAN) / Polish Academy of Sciences Poland (PL) University of Manchester United Kingdom (GB) University of Orléans / Université d'Orléans France (FR) Nottingham Trent University United Kingdom (GB) Leiden University Netherlands (NL) Technische Universität Berlin Germany (DE) Thüringer Landessternwarte Tautenburg (TLS) - Karl-Schwarzschild-Observatorium Germany (DE) Rutherford Appleton Laboratory United Kingdom (GB) National Center for Scientific Research / Centre national de la recherche scientifique (CNRS) France (FR) Chalmers University of Technology / Chalmers tekniska högskola Sweden (SE) Universität Hamburg (UHH) Germany (DE) Radboud University Nijmegen Netherlands (NL) Australian National University (ANU) Australia (AU)

How to cite

APA:

Fallows, R.A., Forte, B., Astin, I., Allbrook, T., Arnold, A., Wood, A.,... Zucca, P. (2020). A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances. Journal of Space Weather and Space Climate, 10. https://doi.org/10.1051/swsc/2020010

MLA:

Fallows, Richard A., et al. "A LOFAR observation of ionospheric scintillation from two simultaneous travelling ionospheric disturbances." Journal of Space Weather and Space Climate 10 (2020).

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