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The Worldwide Interplanetary Scintillation (IPS) Stations (WIPSS) Network October 2016 Observing Campaign: Initial WIPSS Data Analyses M.M

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The Worldwide Interplanetary Scintillation (IPS) Stations (WIPSS) Network October 2016 Observing Campaign: Initial WIPSS Data Analyses M.M Fall AGU 2017 - SH21A-2648 The Worldwide Interplanetary Scintillation (IPS) Stations (WIPSS) Network October 2016 Observing Campaign: Initial WIPSS Data Analyses M.M. Bisi {[email protected]} (1) ), R.A. Fallows (2), B.V. Jackson (3), M. Tokumaru (4), J.A. Gonzalez-Esparza (5), J. Morgan (6), I. Chashei (7), J.C. Mejia-Ambriz (5), S.A. Tyul’bashev (7), P.K. Manoharan (8), V. De la Luz (5), E. Aguilar-Rodriguez (5), H.-S. Yu (3), D. Barnes (1), O. Chang (9), D. Odstrcil (10)(11), K. Fujiki (4), and V. Shishov (7). (1) RAL Space, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire, OX11 0QX, England, UK. (2) ASTRON, the Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo, The Netherlands. (3) Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA, 92093-0424, USA. (4) Institute for Space-Earth Environmental, Nagoya University, Furo-Cho, Chikusa-ku, Nagoya 464-8601, Japan. (5) SCiESMEX/MEXART, Instituto de Geofisica, Unidad Michoacan, Universidad Nacional Autonoma de Mexico, Morelia, Mexico. (6) Curtin Institute of Radio Astronomy, Curtin University, Perth, WA, Australia. (7) Lebedev Physics Institute, Pushchino Radio Astronomy Observatory, Pushchino, Moscow Region, Russia. (8) Radio Astronomy Centre, National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, P.O. Box 8, Udhagamandalam (Ooty) 643001, India. (9) Posgrado en Ciencias de la Tierra, Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, Mexico. (10) NASA Goddard Space Flight Center, Greenbelt, MD, USA. (11) School of Physics, Astronomy, and Computational Sciences, George Mason University, 4400 University Drive, Fairfax, VA 22030-4444, USA. 1. Abstract [1] 3. Interplanetary Scintillation (IPS) [2] Interplanetary Scintillation (IPS) allows for the determination of velocity and a proxy for plasma density to be made Analogous to the twinkling of visible stars in the night sky due to density variations in Earth’s throughout the corona and inner heliosphere. Where sufficient observations are undertaken, the results can be used as input to atmosphere, interplanetary scintillation (IPS) is the rapid variation in radio signal from a distant the University of California, San Diego (UCSD) three-dimensional (3-D) time-dependent tomography suite to allow for the full 3-D reconstruction of both velocity and density throughout the inner heliosphere. By combining IPS results from compact radio source caused by density variations (~150 km scale inhomogeneities) propagating multiple observing locations around the planet, we can increase both the temporal and spatial coverage across the whole of outward throughout the heliosphere in the solar wind. the inner heliosphere and hence improve forecast capability. During October 2016, a unique opportunity arose whereby the European-based LOw Frequency ARray (LOFAR) radio telescope was used to make nearly four weeks of continuous Different observing frequencies enable IPS to be probed across different distance ranges from the observations of IPS as a heliospheric space-weather trial campaign. This was expanded into a global effort to include Sun with higher frequencies probing closer to the Sun, and lower frequencies further away. The observations of IPS from the Murchison Widefield Array (MWA) in Western Australia and many more observations from LOFAR high band frequency range (see below) enables observations of IPS from as close to the Sun various IPS-dedicated WIPSS Network systems. LOFAR is a next-generation low-frequency radio interferometer capable of as ~50 solar radii (well inside the orbit of Mercury) to around Earth-orbit, a crucial distance range observing in the radio frequency range 10-250 MHz, nominally with up to 80 MHz bandwidth at a time. MWA in Western Australia is capable of observing in the 80-300 MHz frequency range nominally using up to 32 MHz of bandwidth. IPS data for probing potential Earth-bound space weather causing events. from LOFAR, ISEE, the MEXican Array Radio Telescope (MEXART), and, where possible, other WIPSS Network systems (such as LPI-BSA and Ooty), will be used in this study and we will present some initial findings for these data sets. We also IPS can be used for various coronal and inner-heliospheric studies, including: determining the make a first attempt at the 3-D reconstruction of multiple pertinent WIPSS results in the UCSD tomography. We will also try plasma velocity of structures flowing out from the Sun such as the solar wind, CMEs, SIRs; to highlight some of the potential future tools that make LOFAR a very unique system to be able to test and validate a whole estimates of plasma density variation/turbulence; assessments of flow directions; and if incorporated plethora of IPS analysis methods with the same set of IPS data. into the University of California, San Diego (UCSD) 3-D tomography, the ability to produce inner- heliospheric reconstructions in both velocity and density structure out to at least 3 AU. 2. Introduction This image cannot currently be displayed. Coronal Mass Ejections (CMEs), their Interplanetary counterparts (ICMEs), and their effects on the 4. The Low Frequency Array (LOFAR) High-Band Tiles 110 to ~250 MHz. Low-Band Dipoles Earth environment, are well studied but a lot still remains to be discovered (e.g. Bisi et al., 2010, and LOFAR presently has 40 stations in The ~10 to ~90 MHz. references therein). When a CME erupts from the Sun, a large amount of mass (solar plasma) and Netherlands, plus five stations across magnetic energy from the solar atmosphere is transported out into the interplanetary medium. Germany, three in Poland, and one each in The term “space weather” covers the effects of the Sun on the Earth and can be considered to have France, Sweden, and the United Kingdom, two main strands: (i) scientific research, and (ii) applications. The former is self-explanatory, but the with several more are under construction. latter covers operational aspects including forecasting. Understanding the complex interactions and This provides additional sensitivity and the structure of the solar wind is crucial to space weather and in preparing for a safe human presence increased angular resolution on geographic in space as well as for protecting our own assets in Earth orbit and our infrastructure on the ground. baselines extending to around 2,000 km. LOFAR superterp (NL; right bottom) and CMEs are associated with the most-intense cases of space weather at the Earth – although other LOFAR Chilbolton (UK; top) shown. conditions such as high-speed streams (HSSs) and stream interaction regions (SIRs) can also have LOFAR High-Band Antenna (HBA) (top – in similar, but generally lesser, effects. The background solar wind needs good characterisation for the background) and LOFAR Low-Band effective space-weather forecasting, and remotely-sensed plasma parameters play a key role here. Antenna (LBA) (top – in the foreground). 5. UCSD 3-D Tomography [3] A potential jet-like (~1,000 km s-1) feature in LASCO can also be seen in the reconstructions. [4] The three-dimensional (3-D) reconstructions used here with the University of California, San Diego 10/17 21:38 10/17 21:49 (UCSD) time-dependent kinematic model have a one-day cadence and 20° x20° latitude and Interesting longitude resolution for current ISEE IPS data. The resolution is predicated by the numbers of lines feature of sight available for the reconstruction. The reconstructions can be used for both science and forecasting. In this study, we perform the first 3-D reconstructions using LOFAR IPS data as well Interesting as combined LOFAR and ISEE data for the October 2016 WIPSS space-weather campaign. feature 10/17 22:00 10/17 22:12 ~3 RS in ~34 minutes Earth >1,000 km s-1 There is much promise here for interesting science as well as investigating the use and scope of the UCSD 3-D tomography and how WIPSS data will lead to more-complete and more-accurate 6. LOFAR Cross-Correlation Analyses reconstructions globally of the inner heliosphere, particularly for smaller-scale feature detections. By cross-correlating the frequency power spectra of two simultaneous 8. The Worldwide IPS Stations (WIPSS) Network WIPSS Core Members: time series, a cross-correlation function (CCF) is formed where specific M.M. Bisi (STFC RAL Space, UK); J.A. Pushchino 111 MHz 2 ISEE Multi-Station 327 MHz Gonzalez-Esparza, E. Aguilar-Rodriguez, features in CCFs can be attributed to known phenomena flowing out 70,000 m 2 2 2000 m ×2, 3500 m ×1 MEXART O. Chang, J.C. Mejia-Ambriz, V.H. De la from the Sun through the corona and inner heliosphere. Peaks in the 140 MHz、10,000 m2 Luz, P. Corona-Romero, and E. Romero- CCF provide velocity estimates for such features crossing the IPS line of Hernandez (SCIESMEX/MEXART/ sight. In some circumstances, the CCF of simultaneous IPS observations UNAM, Mexico); B.V. Jackson, and Hsiu- of a CME from two or more widely-separated radio arrays/telescopes Shan Yu (CASS-UCSD, USA); M. This image cannot currently be displayed. Mexico High-Band Tiles Low-Band Dipoles Tokumaru, and K. Fujiki (ISEE, Nagoya 110 to ~250 MHz. ~10 to 90 MHz. Japan shows a negative lobe near-to/at zero time-lag. Early modelling results University, Japan); I.V. Chashei, S.A. suggest that this is likely related to the orientation of the magnetic field Russia UK/Europe – Tyul'bashev, V. Shishov (Lebedev Physical in the CME. An initial assessment of the HELCATS IPS Catalogues EISCAT/LOFAR Institute, Russia); R.A. Fallows (ASTRON, (IPSCAT – see: https://www.helcats-fp7.eu/catalogues/wp7_ipscat.html WIPSS The Netherlands); and P.K. Manoharan (Ooty Radio Telescope, India). Future for further information) corroborates this with CME features observed in India expected additions (some are much more the STEREO white-/visible-light heliospheric imagers.
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