Imperial College London

ProfessorTimothyHorbury

Faculty of Natural SciencesDepartment of Physics

Professor of Physics
 
 
 
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Contact

 

+44 (0)20 7594 7676t.horbury Website

 
 
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Location

 

H/6M72Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

153 results found

Owens MJ, Riley P, Horbury TS, 2017, Probabilistic Solar Wind and Geomagnetic Forecasting Using an Analogue Ensemble or "Similar Day" Approach, SOLAR PHYSICS, Vol: 292, ISSN: 0038-0938

JOURNAL ARTICLE

Riley P, Ben-Nun M, Linker JA, Owens MJ, Horbury TSet al., 2017, Forecasting the properties of the solar wind using simple pattern recognition, SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS, Vol: 15, Pages: 526-540, ISSN: 1542-7390

JOURNAL ARTICLE

Bale SD, Goetz K, Harvey PR, Turin P, Bonnell JW, Dudok de Wit T, Ergun RE, MacDowall RJ, Pulupa M, Andre M, Bolton M, Bougeret J-L, Bowen TA, Burgess D, Cattell CA, Chandran BDG, Chaston CC, Chen CHK, Choi MK, Connerney JE, Cranmer S, Diaz-Aguado M, Donakowski W, Drake JF, Farrell WM, Fergeau P, Fermin J, Fischer J, Fox N, Glaser D, Goldstein M, Gordon D, Hanson E, Harris SE, Hayes LM, Hinze JJ, Hollweg JV, Horbury TS, Howard RA, Hoxie V, Jannet G, Karlsson M, Kasper JC, Kellogg PJ, Kien M, Klimchuk JA, Krasnoselskikh VV, Krucker S, Lynch JJ, Maksimovic M, Malaspina DM, Marker S, Martin P, Martinez-Oliveros J, McCauley J, McComas DJ, McDonald T, Meyer-Vernet N, Moncuquet M, Monson SJ, Mozer FS, Murphy SD, Odom J, Oliverson R, Olson J, Parker EN, Pankow D, Phan T, Quataert E, Quinn T, Ruplin SW, Salem C, Seitz D, Sheppard DA, Siy A, Stevens K, Summers D, Szabo A, Timofeeva M, Vaivads A, Velli M, Yehle A, Werthimer D, Wygant JRet al., 2016, The FIELDS Instrument Suite for Solar Probe Plus, SPACE SCIENCE REVIEWS, Vol: 204, Pages: 49-82, ISSN: 0038-6308

JOURNAL ARTICLE

Chen CHK, Matteini L, Burgess D, Horbury TSet al., 2016, Magnetic field rotations in the solar wind at kinetic scales (vol 453, L64, 2015), MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 455, Pages: L51-L51, ISSN: 0035-8711

JOURNAL ARTICLE

Mallet A, Schekochihin AA, Chandran BDG, Chen CHK, Horbury TS, Wicks RT, Greenan CCet al., 2016, Measures of three-dimensional anisotropy and intermittency in strong Alfvénic turbulence, Monthly Notices of the Royal Astronomical Society, Vol: 459, Pages: 2130-2139, ISSN: 1365-2966

We measure the local anisotropy of numerically simulated strong Alfvénic turbulence with respect to two local, physically relevant directions: along the local mean magnetic field and along the local direction of one of the fluctuating Elsasser fields. We find significant scaling anisotropy with respect to both these directions: the fluctuations are ‘ribbon-like’ – statistically, they are elongated along both the mean magnetic field and the fluctuating field. The latter form of anisotropy is due to scale-dependent alignment of the fluctuating fields. The intermittent scalings of the nth-order conditional structure functions in the direction perpendicular to both the local mean field and the fluctuations agree well with the theory of Chandran, Schekochihin & Mallet, while the parallel scalings are consistent with those implied by the critical-balance conjecture. We quantify the relationship between the perpendicular scalings and those in the fluctuation and parallel directions, and find that the scaling exponent of the perpendicular anisotropy (i.e. of the aspect ratio of the Alfvénic structures in the plane perpendicular to the mean magnetic field) depends on the amplitude of the fluctuations. This is shown to be equivalent to the anticorrelation of fluctuation amplitude and alignment at each scale. The dependence of the anisotropy on amplitude is shown to be more significant for the anisotropy between the perpendicular and fluctuation-direction scales than it is between the perpendicular and parallel scales.

JOURNAL ARTICLE

Stansby D, Horbury TS, Chen CHK, Matteini Let al., 2016, EXPERIMENTAL DETERMINATION OF WHISTLER WAVE DISPERSION RELATION IN THE SOLAR WIND, ASTROPHYSICAL JOURNAL LETTERS, Vol: 829, ISSN: 2041-8205

JOURNAL ARTICLE

Archer MO, Horbury TS, Brown P, Eastwood JP, Oddy TM, Whiteside BJ, Sample JGet al., 2015, The MAGIC of CINEMA: first in-flight science results from a miniaturised anisotropic magnetoresistive magnetometer, ANNALES GEOPHYSICAE, Vol: 33, Pages: 725-735, ISSN: 0992-7689

JOURNAL ARTICLE

Archer MO, Turner DL, Eastwood JP, Schwartz SJ, Horbury TSet al., 2015, Global impacts of a Foreshock Bubble: Magnetosheath, magnetopause and ground-based observations, PLANETARY AND SPACE SCIENCE, Vol: 106, Pages: 56-66, ISSN: 0032-0633

JOURNAL ARTICLE

Chen CHK, Matteini L, Burgess D, Horbury TSet al., 2015, Magnetic field rotations in the solar wind at kinetic scales, MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Vol: 453, Pages: L64-L68, ISSN: 0035-8711

JOURNAL ARTICLE

Matteini L, Horbury TS, Pantellini F, Velli M, Schwartz SJet al., 2015, ION KINETIC ENERGY CONSERVATION AND MAGNETIC FIELD STRENGTH CONSTANCY INMULTI-FLUID SOLAR WIND ALFVÉNIC TURBULENCE, Astrophysical Journal, Vol: 802, ISSN: 1538-4357

We investigate the properties of plasma fluid motion in the large-amplitude, low-frequency fluctuations of highlyAlfvénic fast solar wind. We show that protons locally conserve total kinetic energy when observed from aneffective frame of reference comoving with the fluctuations. For typical properties of the fast wind, this frame canbe reasonably identified by alpha particles which, due to their drift with respect to protons at about the Alfvénspeed along the magnetic field, do not partake in the fluid low-frequency fluctuations. Using their velocity totransform the proton velocity into the frame of Alfvénic turbulence, we demonstrate that the resulting plasmamotion is characterized by a constant absolute value of the velocity, zero electric fields, and aligned velocity andmagnetic field vectors as expected for unidirectional Alfvénic fluctuations in equilibrium. We propose that thisconstraint, via the correlation between velocity and magnetic field in Alfvénic turbulence, is the origin of theobserved constancy of the magnetic field; while the constant velocity corresponding to constant energy can only beobserved in the frame of the fluctuations, the corresponding constant total magnetic field, invariant for Galileantransformations, remains the observational signature in the spacecraft frame of the constant total energy in theAlfvén turbulence frame

JOURNAL ARTICLE

Archer MO, Turner DL, Eastwood JP, Horbury TS, Schwartz SJet al., 2014, The role of pressure gradients in driving sunward magnetosheath flows and magnetopause motion, JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 119, Pages: 8117-8125, ISSN: 2169-9380

JOURNAL ARTICLE

Brown P, Whiteside BJ, Beek TJ, Fox P, Horbury TS, Oddy TM, Archer MO, Eastwood JP, Sanz-Hernndez D, Sample JG, Cupido E, O'Brien H, Carr CMet al., 2014, Space magnetometer based on an anisotropic magnetoresistive hybrid sensor, REVIEW OF SCIENTIFIC INSTRUMENTS, Vol: 85, ISSN: 0034-6748

JOURNAL ARTICLE

Matteini L, Horbury TS, Neugebauer M, Goldstein BEet al., 2014, Dependence of solar wind speed on the local magnetic field orientation: Role of Alfvenic fluctuations, GEOPHYSICAL RESEARCH LETTERS, Vol: 41, Pages: 259-265, ISSN: 0094-8276

JOURNAL ARTICLE

Owens MJ, Horbury TS, Wicks RT, McGregor SL, Savani NP, Xiong Met al., 2014, Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting, SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS, Vol: 12, Pages: 395-405, ISSN: 1542-7390

JOURNAL ARTICLE

Whiteside BJ, Brown P, Beek TJ, Horbury TS, Carr CMet al., 2014, TID response of a Hybrid AMR vector magnetometer

© 2014 IEEE. We present TID response up to 100 kRad(Si), of the three-axis vector magnetoresistive hybrid MAGIC, a low resource magnetometer integrated with a H-bridge drive on a co-fired ceramic chip.

CONFERENCE PAPER

Wicks RT, Roberts DA, Mallet A, Schekochihin AA, Horbury TS, Chen CHKet al., 2014, CORRELATIONS AT LARGE SCALES AND THE ONSET OF TURBULENCE IN THE FAST SOLAR WIND (vol 778, pg 177, 2013), ASTROPHYSICAL JOURNAL, Vol: 782, ISSN: 0004-637X

JOURNAL ARTICLE

Alexandrova O, Chen CHK, Sorriso-Valvo L, Horbury TS, Bale SDet al., 2013, Solar Wind Turbulence and the Role of Ion Instabilities, SPACE SCIENCE REVIEWS, Vol: 178, Pages: 101-139, ISSN: 0038-6308

JOURNAL ARTICLE

Archer MO, Hartinger MD, Horbury TS, 2013, Magnetospheric "magic" frequencies as magnetopause surface eigenmodes, GEOPHYSICAL RESEARCH LETTERS, Vol: 40, Pages: 5003-5008, ISSN: 0094-8276

JOURNAL ARTICLE

Archer MO, Horbury TS, 2013, Magnetosheath dynamic pressure enhancements: occurrence and typical properties, ANNALES GEOPHYSICAE, Vol: 31, Pages: 319-331, ISSN: 0992-7689

JOURNAL ARTICLE

Archer MO, Horbury TS, Eastwood JP, Weygand JM, Yeoman TKet al., 2013, Magnetospheric response to magnetosheath pressure pulses: A low-pass filter effect, JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 118, Pages: 5454-5466, ISSN: 2169-9380

JOURNAL ARTICLE

Forman MA, Wicks RT, Horbury TS, Oughton Set al., 2013, Scaling Anisotropy of the Power in Parallel and Perpendicular Components of the Solar Wind Magnetic Field, 13th International Solar Wind Conference (Solar Wind), Publisher: AMER INST PHYSICS, Pages: 167-170, ISSN: 0094-243X

CONFERENCE PAPER

Seo Y, Chae KS, Mochizuki B, Clarino D, Yeung N, Yoon S, Seon J, Jin H, Lee DH, Lin RP, Sample J, Immel T, Brown P, Horbury TSet al., 2013, Instrument interface module between the on-board-computer and payloads in cinema CUBESAT as developed with FPGA, Pages: 4275-4281, ISSN: 0074-1795

TRiplet Ionospheric Observatory-Cubesat for Ion, Neutral, Electron and MAgnetic fields (TRIO-CINEMA) is a space science mission consisting of three identical 3U CubeSats to provide stereo Energetic Neutral Atom (ENA) imaging of the ring current, multi-point in-situ measurement of supra thermal electrons and ions, and measurement of magnetic fields in Low Earth Orbit (LEO). Each spacecraft is equipped with a Supra Thermal Electrons, Ions, Neutrals (STEIN) instrument and a MAGnetometer from Imperial College (MAGIC) instrument in order to measure the plasma particles with diverse species and energies and magnetic fields. STEIN is able to distinguish electrons, ions, and neut rals by applying electric field in the entrance aperture. MAGIC is a dual 3-axis magnetoresistive sensor intended for attitude control and scientific measurement. The standard spacecraft CubeSat employed for the TRIO- CINEMA mission often utilizes Commercial-Off-The Shelf (COTS) electronics to build bus avionics that provides power and communications, whereas payloads are usually built in accordance with specific requirements that are often more demanding in terms of generation, transmission and storage of the data and power consumption. Therefore, designing and developing the interface to be compatible between mission payloads and the CubeSat avionics built with COTS will be required for many CubeSat missions. In this presentation, we describe the instrument interface module between the On-Board-Computer (OBC) and the mission payloads for TRIO-CINEMA spacecraft. The module is developed to provide required communication and power interfaces. In the instrument interface module, a Field Programmable Gate Array (FPGA) is employed to support computing power of the OBC and communication interfaces. It is exclusively operated as data buffer and framer for generated data from mission payloads and their subsequent transmission through S-band to the ground station. The interface module provides various elec

CONFERENCE PAPER

Wicks RT, Mallet A, Horbury TS, Chen CHK, Schekochihin AA, Mitchell JJet al., 2013, Alignment and Scaling of Large-Scale Fluctuations in the Solar Wind, PHYSICAL REVIEW LETTERS, Vol: 110, ISSN: 0031-9007

JOURNAL ARTICLE

Wicks RT, Matteini L, Horbury TS, Hellinger P, Roberts DAet al., 2013, Temperature anisotropy instabilities; combining plasma and magnetic field data at different distances from the Sun., 13th International Solar Wind Conference (Solar Wind), Publisher: AMER INST PHYSICS, Pages: 303-306, ISSN: 0094-243X

CONFERENCE PAPER

Wicks RT, Roberts DA, Mallet A, Schekochihin AA, Horbury TS, Chen CHKet al., 2013, CORRELATIONS AT LARGE SCALES AND THE ONSET OF TURBULENCE IN THE FAST SOLAR WIND, ASTROPHYSICAL JOURNAL, Vol: 778, ISSN: 0004-637X

JOURNAL ARTICLE

Archer MO, Horbury TS, Eastwood JP, 2012, Magnetosheath pressure pulses: Generation downstream of the bow shock from solar wind discontinuities, JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, Vol: 117, ISSN: 0148-0227

JOURNAL ARTICLE

Brown P, Beek T, Carr C, O'Brien H, Cupido E, Oddy T, Horbury TSet al., 2012, Magnetoresistive magnetometer for space science applications, MEASUREMENT SCIENCE AND TECHNOLOGY, Vol: 23, ISSN: 0957-0233

JOURNAL ARTICLE

Brown P, Beek T, Carr C, O'Brien H, Cupido E, Oddy T, Horbury TSet al., 2012, Magnetoresistive magnetometer for space science applications (vol 23, 025902, 2012), MEASUREMENT SCIENCE AND TECHNOLOGY, Vol: 23, ISSN: 0957-0233

JOURNAL ARTICLE

Chen CHK, Mallet A, Schekochihin AA, Horbury TS, Wicks RT, Bale SDet al., 2012, THREE-DIMENSIONAL STRUCTURE OF SOLAR WIND TURBULENCE, ASTROPHYSICAL JOURNAL, Vol: 758, ISSN: 0004-637X

JOURNAL ARTICLE

Dover NP, Palmer CAJ, Babzien M, Bell AR, Dangor AE, Horbury T, Ispiriyan M, Polyanskiy MN, Schreiber J, Schwartz S, Shkolnikov P, Yakimenko V, Pogorelsky I, Najmudin Zet al., 2012, Optical probing of shocks driven into overdense plasmas by laser hole-boring

Observations of the interaction of an intense {\lambda}0 \approx 10 {\mu}mlaser pulse with near-critical overdense plasmas (ne = 1.8 - 3 nc) arepresented. For the first time, transverse optical probing is used to show arecession of the front surface caused by radiation pressure driven hole-boringby the laser pulse with an initial velocity > 10^6 ms-1, and the resultingcollisionless shocks. The collisionless shock propagates through the plasma,dissipates into an ion-acoustic solitary wave, and eventually becomescollisional as it slows further. These conclusions are supported by PICsimulations which show that the initial evolution is dominated by collisionlessmechanisms.

JOURNAL ARTICLE

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