Burston, Raymond B.

[["dc.bibliographiccitation.artnumber","A138"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","567"],["dc.contributor.author","Roudier, Thierry"],["dc.contributor.author","Švanda, Michal"],["dc.contributor.author","Rieutord, M."],["dc.contributor.author","Malherbe, J. M."],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Gizon, Laurent"],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2014"],["dc.description.abstract","Studying the motions on the solar surface is fundamental for understanding how turbulent convection transports energy and how magnetic fields are distributed across the solar surface. From horizontal velocity measurements all over the visible disc of the Sun and using data from the Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI), we investigate the structure and evolution of solar supergranulation. Horizontal velocity fields were measured by following the proper motions of solar granules using a newly developed version of the coherent structure tracking code. With this tool, maps of horizontal divergence were computed. We then segmented and identified supergranular cells and followed their histories by using spatio-temporal labelling. With this data set we derived the fundamental properties of supergranulation, including their motion. We find values of the fundamental parameters of supergranulation similar to previous studies: a mean lifetime of 1.5 days and a mean diameter of 25 Mm. The tracking of individual supergranular cells reveals the solar differential rotation and a poleward circulation trend of the meridional flow. The shape of the derived differential rotation and meridional flow does not depend on the cell size. If there is a background magnetic field, the diverging flows in supergranules are weaker. This study confirms that supergranules are suitable tracers that may be used to investigate the large-scale flows of the solar convection as long as they are detectable enough on the surface."],["dc.identifier.doi","10.1051/0004-6361/201423577"],["dc.identifier.fs","609661"],["dc.identifier.gro","3147039"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10927"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4772"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Structure and evolution of solar supergranulation using SDO/HMI data"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","201"],["dc.bibliographiccitation.issue","1-4"],["dc.bibliographiccitation.journal","Space Science Reviews"],["dc.bibliographiccitation.lastpage","219"],["dc.bibliographiccitation.volume","196"],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Birch, Aaron C."],["dc.date.accessioned","2017-09-07T11:49:43Z"],["dc.date.available","2017-09-07T11:49:43Z"],["dc.date.issued","2015"],["dc.description.abstract","Time-distance helioseismology uses cross-covariances of wave motions on the solar surface to determine the travel times of wave packets moving from one surface location to another. We review the methodology to interpret travel-time measurements in terms of small, localised perturbations to a horizontally homogeneous reference solar model. Using the first Born approximation, we derive and compute 3D travel-time sensitivity (Fréchet) kernels for perturbations in sound-speed, density, pressure, and vector flows. While kernels for sound speed and flows had been computed previously, here we extend the calculation to kernels for density and pressure, hence providing a complete description of the effects of solar dynamics and structure on travel times. We treat three thermodynamic quantities as independent and do not assume hydrostatic equilibrium. We present a convenient approach to computing damped Green’s functions using a normal-mode summation. The Green’s function must be computed on a wavenumber grid that has sufficient resolution to resolve the longest lived modes. The typical kernel calculations used in this paper are computer intensive and require on the order of 600 CPU hours per kernel. Kernels are validated by computing the travel-time perturbation that results from horizontally-invariant perturbations using two independent approaches. At fixed sound-speed, the density and pressure kernels are approximately related through a negative multiplicative factor, therefore implying that perturbations in density and pressure are difficult to disentangle. Mean travel-times are not only sensitive to sound-speed, density and pressure perturbations, but also to flows, especially vertical flows. Accurate sensitivity kernels are needed to interpret complex flow patterns such as convection."],["dc.identifier.doi","10.1007/s11214-015-0136-0"],["dc.identifier.gro","3147407"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4996"],["dc.language.iso","en"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0038-6308"],["dc.title","Interpretation of Helioseismic Travel Times"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A107"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","595"],["dc.contributor.author","Schunker, H."],["dc.contributor.author","Braun, D. C."],["dc.contributor.author","Birch, A. C."],["dc.contributor.author","Burston, R. B."],["dc.contributor.author","Gizon, L."],["dc.date.accessioned","2017-09-07T11:49:59Z"],["dc.date.available","2017-09-07T11:49:59Z"],["dc.date.issued","2016"],["dc.description.abstract","Context. Observations from the Solar Dynamics Observatory (SDO) have the potential for allowing the helioseismic study of the formation of hundreds of active regions, which would enable us to perform statistical analyses. Aims. Our goal is to collate a uniform data set of emerging active regions observed by the SDO/HMI instrument suitable for helioseismic analysis, where each active region is centred on a 60° × 60° area and can be observed up to seven days before emergence. Methods. We restricted the sample to active regions that were visible in the continuum and emerged into quiet Sun largely avoiding pre-existing magnetic regions. As a reference data set we paired a control region (CR), with the same latitude and distance from central meridian, with each emerging active region (EAR). The control regions do not have any strong emerging flux within 10° of the centre of the map. Each region was tracked at the Carrington rotation rate as it crossed the solar disk, within approximately 65° from the central meridian and up to seven days before, and seven days after, emergence. The mapped and tracked data, consisting of line-of-sight velocity, line-of-sight magnetic field, and intensity as observed by SDO/HMI, are stored in datacubes that are 410 min in duration and spaced 320 min apart. We call this data set, which is currently comprised of 105 emerging active regions observed between May 2010 and November 2012, the SDO Helioseismic Emerging Active Region (SDO/HEAR) survey. Results. To demonstrate the utility of a data set of a large number of emerging active regions, we measure the relative east-west velocity of the leading and trailing polarities from the line-of-sight magnetogram maps during the first day after emergence. The latitudinally averaged line-of-sight magnetic field of all the EARs shows that, on average, the leading (trailing) polarity moves in a prograde (retrograde) direction with a speed of 121 ± 22 m s-1 (−70 ± 13 m s-1) relative to the Carrington rotation rate in the first day. However, relative to the differential rotation of the surface plasma, the east-west velocity is symmetric, with a mean of 95 ± 13 m s-1. Conclusions. The SDO/HEAR data set will not only be useful for helioseismic studies, but will also be useful to study other features such as the surface magnetic field evolution of a large sample of EARs. We intend to extend this survey forwards in time to include more EARs observed by SDO/HMI."],["dc.identifier.doi","10.1051/0004-6361/201628388"],["dc.identifier.gro","3147477"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/14279"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5026"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","SDO/HMI survey of emerging active regions for helioseismology"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","A53"],["dc.bibliographiccitation.journal","Astronomy and Astrophysics"],["dc.bibliographiccitation.volume","625"],["dc.contributor.author","Schunker, Hannah"],["dc.contributor.author","Birch, A. C."],["dc.contributor.author","Cameron, R. H."],["dc.contributor.author","Braun, D. C."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Burston, R. B."],["dc.date.accessioned","2020-12-10T18:11:46Z"],["dc.date.available","2020-12-10T18:11:46Z"],["dc.date.issued","2019"],["dc.identifier.doi","10.1051/0004-6361/201834627"],["dc.identifier.eissn","1432-0746"],["dc.identifier.issn","0004-6361"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/74133"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Average motion of emerging solar active region polarities"],["dc.title.alternative","I. Two phases of emergence"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","A113"],["dc.bibliographiccitation.journal","Astronomy & Astrophysics"],["dc.bibliographiccitation.volume","552"],["dc.contributor.author","Roudier, Thierry"],["dc.contributor.author","Rieutord, M."],["dc.contributor.author","Prat, V."],["dc.contributor.author","Malherbe, J. M."],["dc.contributor.author","Renon, N."],["dc.contributor.author","Frank, Z."],["dc.contributor.author","Švanda, Michal"],["dc.contributor.author","Berger, Thomas"],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Gizon, Laurent"],["dc.date.accessioned","2017-09-07T11:48:42Z"],["dc.date.available","2017-09-07T11:48:42Z"],["dc.date.issued","2013"],["dc.identifier.doi","10.1051/0004-6361/201220867"],["dc.identifier.gro","3147037"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/10134"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4771"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","EDP Sciences"],["dc.relation.issn","0004-6361"],["dc.relation.orgunit","Fakultät für Physik"],["dc.title","Comparison of solar horizontal velocity fields from SDO/HMI and Hinode data"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","329"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Experimental Astronomy"],["dc.bibliographiccitation.lastpage","391"],["dc.bibliographiccitation.volume","40"],["dc.contributor.author","Tinetti, Giovanna"],["dc.contributor.author","Drossart, Pierre"],["dc.contributor.author","Eccleston, Paul"],["dc.contributor.author","Hartogh, Paul"],["dc.contributor.author","Isaak, Kate"],["dc.contributor.author","Linder, Martin"],["dc.contributor.author","Lovis, Christophe"],["dc.contributor.author","Micela, Giusi"],["dc.contributor.author","Ollivier, Marc"],["dc.contributor.author","Rengel, Malte"],["dc.contributor.author","Sousa, S."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Affer, L."],["dc.date.accessioned","2021-03-05T09:05:20Z"],["dc.date.available","2021-03-05T09:05:20Z"],["dc.date.issued","2015"],["dc.identifier.doi","10.1007/s10686-015-9484-8"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/80444"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-393"],["dc.relation.eissn","1572-9508"],["dc.relation.issn","0922-6435"],["dc.title","The EChO science case"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","491"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Experimental Astronomy"],["dc.bibliographiccitation.lastpage","527"],["dc.bibliographiccitation.volume","23"],["dc.contributor.author","Appourchaux, Thierry"],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Chen, Yanbei"],["dc.contributor.author","Cruise, Michael"],["dc.contributor.author","Dittus, Hansjörg"],["dc.contributor.author","Foulon, Bernard"],["dc.contributor.author","Gill, Patrick"],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Klein, Hugh"],["dc.contributor.author","Klioner, Sergei"],["dc.contributor.author","Kopeikin, Sergei"],["dc.contributor.author","Krüger, Hans"],["dc.contributor.author","Lämmerzahl, Claus"],["dc.contributor.author","Lobo, Alberto"],["dc.contributor.author","Luo, Xinlian"],["dc.contributor.author","Margolis, Helen"],["dc.contributor.author","Ni, Wei-Tou"],["dc.contributor.author","Patón, Antonio Pulido"],["dc.contributor.author","Peng, Qiuhe"],["dc.contributor.author","Peters, Achim"],["dc.contributor.author","Rasel, Ernst"],["dc.contributor.author","Rüdiger, Albrecht"],["dc.contributor.author","Samain, Étienne"],["dc.contributor.author","Selig, Hanns"],["dc.contributor.author","Shaul, Diana"],["dc.contributor.author","Sumner, Timothy"],["dc.contributor.author","Theil, Stephan"],["dc.contributor.author","Touboul, Pierre"],["dc.contributor.author","Turyshev, Slava"],["dc.contributor.author","Wang, Haitao"],["dc.contributor.author","Wang, Li"],["dc.contributor.author","Wen, Linqing"],["dc.contributor.author","Wicht, Andreas"],["dc.contributor.author","Wu, Ji"],["dc.contributor.author","Zhang, Xiaomin"],["dc.contributor.author","Zhao, Cheng"],["dc.date.accessioned","2017-09-07T11:49:44Z"],["dc.date.available","2017-09-07T11:49:44Z"],["dc.date.issued","2009"],["dc.description.abstract","ASTROD I is a planned interplanetary space mission with multiple goals. The primary aims are: to test general relativity with an improvement in sensitivity of over three orders of magnitude, improving our understanding of gravity and aiding the development of a new quantum gravity theory; to measure key solar system parameters with increased accuracy, advancing solar physics and our knowledge of the solar system; and to measure the time rate of change of the gravitational constant with an order of magnitude improvement and the anomalous Pioneer acceleration, thereby probing dark matter and dark energy gravitationally. It is an international project, with major contributions from Europe and China and is envisaged as the first in a series of ASTROD missions. ASTROD I will consist of one spacecraft carrying a telescope, four lasers, two event timers and a clock. Two-way, two-wavelength laser pulse ranging will be used between the spacecraft in a solar orbit and deep space laser stations on Earth, to achieve the ASTROD I goals. A second mission, ASTROD (ASTROD II) is envisaged as a three-spacecraft mission which would test General Relativity to 1 ppb, enable detection of solar g-modes, measure the solar Lense–Thirring effect to 10 ppm, and probe gravitational waves at frequencies below the LISA bandwidth. In the third phase (ASTROD III or Super-ASTROD), larger orbits could be implemented to map the outer solar system and to probe primordial gravitational-waves at frequencies below the ASTROD II bandwidth."],["dc.identifier.doi","10.1007/s10686-008-9131-8"],["dc.identifier.gro","3147392"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4986"],["dc.language.iso","en"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.relation.issn","0922-6435"],["dc.title","Astrodynamical Space Test of Relativity Using Optical Devices I (ASTROD I)—A class-M fundamental physics mission proposal for Cosmic Vision 2015–2025"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","32"],["dc.bibliographiccitation.firstpage","32"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","The Astrophysical Journal"],["dc.bibliographiccitation.volume","771"],["dc.contributor.author","Švanda, Michal"],["dc.contributor.author","Roudier, Thierry"],["dc.contributor.author","Rieutord, Michel"],["dc.contributor.author","Burston, Raymond"],["dc.contributor.author","Gizon, Laurent"],["dc.date.accessioned","2017-09-07T11:48:43Z"],["dc.date.available","2017-09-07T11:48:43Z"],["dc.date.issued","2013"],["dc.identifier.doi","10.1088/0004-637x/771/1/32"],["dc.identifier.gro","3147046"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4778"],["dc.notes.intern","DOI Import GROB-393"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","chake"],["dc.publisher","IOP Publishing"],["dc.relation.eissn","1538-4357"],["dc.relation.issn","0004-637X"],["dc.title","Comparison of Solar Surface Flows Inferred from Time-Distance Helioseismology and Coherent Structure Tracking Using HMI/ SDO Observations"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Astronomische Nachrichten"],["dc.bibliographiccitation.volume","332"],["dc.contributor.author","Birch, Aaron C."],["dc.contributor.author","Gizon, Laurent"],["dc.contributor.author","Burston, Raymond"],["dc.date.accessioned","2017-09-07T11:48:38Z"],["dc.date.available","2017-09-07T11:48:38Z"],["dc.date.issued","2011"],["dc.identifier.doi","10.1002/asna.201111557"],["dc.identifier.gro","3146965"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/4729"],["dc.notes.status","public"],["dc.notes.submitter","chake"],["dc.publisher","Wiley-Blackwell"],["dc.relation.iserratumof","/handle/2/4728"],["dc.relation.issn","0004-6337"],["dc.title","Erratum: Linear sensitivity of helioseismic travel times to local flows"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dc.type.subtype","erratum_ja"],["dspace.entity.type","Publication"]]