Decoding solar wind-magnetosphere coupling

被引:6
|
作者
Beharrell, M. J. [1 ]
Honary, F. [1 ]
机构
[1] Univ Lancaster, Dept Phys, Lancaster, England
来源
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS | 2016年 / 14卷 / 10期
关键词
GEOMAGNETIC-ACTIVITY; DST MODEL; SYM-H; D-ST; ENERGY; FIELD; DISTURBANCE; PHASE; INDEX; DECAY;
D O I
10.1002/2016SW001467
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We employ a new NARMAX (Nonlinear Auto-Regressive Moving Average with eXogenous inputs) code to disentangle the time-varying relationship between the solar wind and SYM-H. The NARMAX method has previously been used to formulate a Dst model, using a preselected solar wind coupling function. In this work, which uses the higher-resolution SYM-H in place of Dst, we are able to reveal the individual components of different solar wind-magnetosphere interaction processes as they contribute to the geomagnetic disturbance. This is achieved with a graphics processing unit (GPU)-based NARMAX code that is around 10 orders of magnitude faster than previous efforts from 2005, before general-purpose programming on GPUs was possible. The algorithm includes a composite cost function, to minimize overfitting, and iterative reorthogonalization, which reduces computational errors in the most critical calculations by a factor of similar to 10(6). The results show that negative deviations in SYM-H following a southward interplanetary magnetic field (IMF) are first a measure of the increased magnetic flux in the geomagnetic tail, observed with a delay of 20-30 min from the time the solar wind hits the bow shock. Terms with longer delays are found which represent the dipolarization of the magnetotail, the injections of particles into the ring current, and their subsequent loss by flowout through the dayside magnetopause. Our results indicate that the contribution of magnetopause currents to the storm time indices increase with solar wind electric field, E = v x B. This is in agreement with previous studies that have shown that the magnetopause is closer to the Earth when the IMF is in the tangential direction.
引用
收藏
页码:724 / 741
页数:18
相关论文
共 50 条
  • [41] Solar wind-magnetosphere energy coupling function fitting: Results froma global MHD simulation
    Wang, C.
    Han, J. P.
    Li, H.
    Peng, Z.
    Richardson, J. D.
    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2014, 119 (08)
  • [42] Both solar wind-magnetosphere coupling and ring current intensity control of the size of the auroral oval
    Milan, Stephen E.
    GEOPHYSICAL RESEARCH LETTERS, 2009, 36
  • [43] Solar wind-magnetosphere coupling efficiency during ejecta and sheath-driven geomagnetic storms
    Myllys, M.
    Kilpua, E. K. J.
    Lavraud, B.
    Pulkkinen, T. I.
    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2016, 121 (05) : 4378 - 4396
  • [44] Global and multi-scale features of solar wind-magnetosphere coupling: From modeling to forecasting
    Ukhorskiy, AY
    Sitnov, MI
    Sharma, AS
    Papadopoulos, K
    GEOPHYSICAL RESEARCH LETTERS, 2004, 31 (08) : L088021 - 4
  • [45] A semiempirical magnetosheath model to analyze the solar wind-magnetosphere interaction
    Kallio, EJ
    Koskinen, HEJ
    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2000, 105 (A12) : 27469 - 27479
  • [46] SOLAR WIND MAGNETOSPHERE COUPLING
    CROOKER, NU
    REVIEWS OF GEOPHYSICS, 1975, 13 (03) : 955 - +
  • [47] Viscous-type processes in the solar wind-magnetosphere interaction
    Charles J. Farrugia
    Fausto T. Gratton
    Roy B. Torbert
    Space Science Reviews, 2001, 95 : 443 - 456
  • [48] Characterizing the Solar Wind-Magnetosphere Viscous Interaction at Uranus and Neptune
    Donaldson, Katelin
    Olsen, Angela J.
    Paty, Carol S.
    Caggiano, Joe
    JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2024, 129 (08)
  • [49] Data-derived analogues of the solar wind-magnetosphere interaction
    Klimas, AJ
    Vassiliadis, D
    Baker, DN
    Valdivia, JA
    PHYSICS AND CHEMISTRY OF THE EARTH PART C-SOLAR-TERRESTIAL AND PLANETARY SCIENCE, 1999, 24 (1-3): : 37 - 44
  • [50] Viscous-type processes in the solar wind-magnetosphere interaction
    Farrugia, CJ
    Gratton, FT
    Torbert, RB
    SPACE SCIENCE REVIEWS, 2001, 95 (1-2) : 443 - 456