Type II radio bursts: 1. New entirely analytic formalism for the electron beams, Langmuir waves, and radio emission

Schmidt, J. M.; Cairns, Iver H.

doi:10.1029/2011ja017318

Cited by 26 publications

(39 citation statements)

References 101 publications

(234 reference statements)

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“…Both were associated with multiple days of strong space weather activity (see http://www.swpc.noaa.gov/weekly/2011_WeeklyPDF/prf1851.pdf and http://www.swpc.noaa.gov/weekly/2012_WeeklyPDF/prf1906.pdf). This agreement strongly supports the validity of the type II theory [ Knock et al , , , ; Knock and Cairns , ; Cairns and Knock , ; Florens et al , ; Schmidt and Cairns , , ] and the quality of the CME simulations. It also opens up a near‐term capability for the extraction of CME properties from radio data combined with simulations for the refinement of space weather predictions at Earth and elsewhere.…”

Section: Introductionsupporting

confidence: 76%

“…In this paper a detailed quantitative test of state‐of‐the‐art type II theory with event‐specific 3‐D CME and shock predictions is carried out. This test combines the radio theory developed at the University of Sydney [ Knock et al , , , ; Knock and Cairns , ; Cairns and Knock , ; Florens et al , ; Schmidt and Cairns , , ] with simulations of the University of Michigan's Block‐Adaptive‐Tree‐Solarwind‐Roe‐Upwind‐Scheme (BATS‐R‐US) magnetohydrodynamic (MHD) code [ Powell et al , ; Roussev et al , , ; Tôth et al , ] for the 15 February 2011 and 7 March 2012 type IIs and CMEs, going beyond a first short application to the 15 February 2011 event [ Schmidt et al , ]. Data from multiple ground (Wilcox, Learmonth) and space (ACE, STEREO, and Wind) platforms are used to develop models for the background corona and CME initiation used in the BATS‐R‐US code.…”

Section: Introductionmentioning

confidence: 99%

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Type II solar radio bursts predicted by 3‐D MHD CME and kinetic radio emission simulations

Schmidt

Cairns

2014

JGR Space Physics

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Citation:Schmidt, J. M., and I. H. Cairns (2014), Type II solar radio bursts predicted by 3-D MHD CME and kinetic radio emission simulations, J. Geophys. Res. Space Physics, 119, 69-87, doi:10.1002 Abstract Impending space weather events at Earth are often signaled by type II solar radio bursts.These bursts are generated upstream of shock waves driven by coronal mass ejections (CMEs) that move away from the Sun. We combine elaborate three-dimensional (3-D) magnetohydrodynamic predictions of realistic CMEs near the Sun with a recent analytic kinetic radiation theory in order to simulate two type II bursts. Magnetograms of the Sun are used to reconstruct initial solar magnetic and active region fields for the modeling. STEREO spacecraft data are used to dimension the flux rope of the initial CME, launched into an empirical data-driven corona and solar wind. We demonstrate impressive accuracy in time, frequency, and intensity for the two type II bursts observed by the Wind spacecraft on 15 February 2011 and 7 March 2012. Propagation of the simulated CME-driven shocks through coronal plasmas containing preexisting density and magnetic field structures that stem from the coronal setup and CME initiation closely reproduce the isolated islands of type II emission observed. These islands form because of a competition between the growth of the radio source due to spherical expansion and a fragmentation of the radio source due to increasingly radial fields in the nose region of the shock and interactions with streamers in the flank regions of the shock. Our study provides strong support for this theory for type II bursts and implies that the physical processes involved are understood. It also supports a near-term capability to predict and track these events for space weather predictions.

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Section: Introductionsupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Type II solar radio bursts predicted by 3‐D MHD CME and kinetic radio emission simulations

Schmidt

Cairns

2014

JGR Space Physics

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“…The spatially varying shock normal and the upstream magnetic field and plasma parameters are taken from the underlying BATS-R-US simulation. The plasma and electron beam parameters are then used to analytically calculate the frequency and radiated power per unit volume for these radio emission processes [Schmidt and Cairns, 2012;Robinson and Cairns, 1998;Knock et al, 2001]. Sufficiently, intense Langmuir waves undergo electrostatic decay into backscattered Langmuir waves and ion acoustic waves.…”

Section: Radio Theory and Observationsmentioning

confidence: 99%

Quantitative prediction of type II solar radio emission from the Sun to 1 AU

Schmidt

Cairns

2016

Geophysical Research Letters

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Coronal mass ejections (CMEs) are frequently associated with shocks and type II solar radio bursts. Despite involving fundamental plasma physics and being the archetype for collective radio emission from shocks, type II bursts have resisted detailed explanation for over 60 years. Between 29 November and 1 December 2013 the two widely separated spacecraft STEREO A and B observed a long lasting, intermittent, type II radio burst from ≈4 MHz to 30 kHz (harmonic), including an intensification when the CME‐driven shock reached STEREO A. We demonstrate the first accurate and quantitative simulation of a type II burst from the high corona (near 11 solar radii) to 1 AU for this event with a combination of a data‐driven three‐dimensional magnetohydrodynamic simulation for the CME and plasma background and an analytic quantitative kinetic model for the radio emission.

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“…Type II radio emission is generated by the conversion of enhanced Langmuir waves to electromagnetic waves, therefore, the radiation is emitted at the fundamental and the first harmonic of the Langmuir frequency, also referred to as electron plasma frequency pe . The enhanced Langmuir turbulence is thought to be caused by energy input due to electrons that are accelerated by the shock wave (see e.g., Schmidt and Cairns, 2012, and references therein). …”

Section: Metric Type II Radio Burstsmentioning

confidence: 99%

Large-scale Globally Propagating Coronal Waves

Warmuth

2015

Living Rev. Sol. Phys.

169

140

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Large-scale, globally propagating wave-like disturbances have been observed in the solar chromosphere and by inference in the corona since the 1960s. However, detailed analysis of these phenomena has only been conducted since the late 1990s. This was prompted by the availability of high-cadence coronal imaging data from numerous spaced-based instruments, which routinely show spectacular globally propagating bright fronts. Coronal waves, as these perturbations are usually referred to, have now been observed in a wide range of spectral channels, yielding a wealth of information. Many findings have supported the "classical" interpretation of the disturbances: fast-mode MHD waves or shocks that are propagating in the solar corona. However, observations that seemed inconsistent with this picture have stimulated the development of alternative models in which "pseudo waves" are generated by magnetic reconfiguration in the framework of an expanding coronal mass ejection. This has resulted in a vigorous debate on the physical nature of these disturbances. This review focuses on demonstrating how the numerous observational findings of the last one and a half decades can be used to constrain our models of large-scale coronal waves, and how a coherent physical understanding of these disturbances is finally emerging. Article RevisionsLiving Reviews supports two ways of keeping its articles up-to-date:Fast-track revision. A fast-track revision provides the author with the opportunity to add short notices of current research results, trends and developments, or important publications to the article. A fast-track revision is refereed by the responsible subject editor. If an article has undergone a fast-track revision, a summary of changes will be listed here.Major update. A major update will include substantial changes and additions and is subject to full external refereeing. It is published with a new publication number.For detailed documentation of an article's evolution, please refer to the history document of the article's online version at http://dx

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Type II radio bursts: 1. New entirely analytic formalism for the electron beams, Langmuir waves, and radio emission

Cited by 26 publications

References 101 publications

Type II solar radio bursts predicted by 3‐D MHD CME and kinetic radio emission simulations

Type II solar radio bursts predicted by 3‐D MHD CME and kinetic radio emission simulations

Quantitative prediction of type II solar radio emission from the Sun to 1 AU

Large-scale Globally Propagating Coronal Waves

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