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Predictions of local ground geomagnetic field fluctuations during the 7-10 November 2004 events studied with solar wind driven models

Wintoft, P; Wik, Magnus LU ; Lundstedt, Henrik LU and Eliasson, L (2005) In Annales Geophysicae 23(9). p.3095-3101
Abstract
The 7-10 November 2004 period contains two events for which the local ground magnetic field was severely disturbed and simultaneously, the solar wind displayed several shocks and negative B-z periods. Using empirical models the 10-min RMS Delta X and Delta Y at Brorfelde (BFE, 11.67 degrees E, 55.63 degrees N), Denmark, are predicted. The models are recurrent neural networks with 10-min solar wind plasma and magnetic field data as inputs. The predictions show a good agreement during 7 November, up until around noon on 8 November, after which the predictions become significantly poorer. The correlations between observed and predicted log RMS Delta X is 0.77 during, 7-8 November but drops to 0.38 during 9-10 November. For RMS Delta Y the... (More)
The 7-10 November 2004 period contains two events for which the local ground magnetic field was severely disturbed and simultaneously, the solar wind displayed several shocks and negative B-z periods. Using empirical models the 10-min RMS Delta X and Delta Y at Brorfelde (BFE, 11.67 degrees E, 55.63 degrees N), Denmark, are predicted. The models are recurrent neural networks with 10-min solar wind plasma and magnetic field data as inputs. The predictions show a good agreement during 7 November, up until around noon on 8 November, after which the predictions become significantly poorer. The correlations between observed and predicted log RMS Delta X is 0.77 during, 7-8 November but drops to 0.38 during 9-10 November. For RMS Delta Y the correlations for the two periods are 0.71 and 0.41, respectively. Studying the solar wind data for other L1-spacecraft (WIND and SOHO) it seems that the ACE data have a better agreement to the near-Earth solar wind during the first two days as compared to the last two days. Thus, the accuracy of the predictions depends on the location of the spacecraft and the solar wind flow direction. Another finding, for the events studied here, is that the Delta X and Delta Y models showed a very different dependence on B-z The Delta X model is almost independent of the solar wind magnetic field B-z except at times when B-z is exceptionally large or when the overall activity is low. On the contrary, the Delta Y model shows a strong dependence on B-z at all times. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
solar wind-magnetosphere, magnetospheric physics, geomagnetism and, paleomagnetism, ionosphere, rapid time variations, forecasting, modeling and
in
Annales Geophysicae
volume
23
issue
9
pages
3095 - 3101
publisher
European Geosciences Union
external identifiers
  • wos:000234166800018
  • scopus:30744459382
ISSN
1432-0576
language
English
LU publication?
yes
id
6689706c-192d-45fe-8792-0c3a0f3a939e (old id 210684)
date added to LUP
2007-08-23 08:23:55
date last changed
2017-02-26 03:37:24
@article{6689706c-192d-45fe-8792-0c3a0f3a939e,
  abstract     = {The 7-10 November 2004 period contains two events for which the local ground magnetic field was severely disturbed and simultaneously, the solar wind displayed several shocks and negative B-z periods. Using empirical models the 10-min RMS Delta X and Delta Y at Brorfelde (BFE, 11.67 degrees E, 55.63 degrees N), Denmark, are predicted. The models are recurrent neural networks with 10-min solar wind plasma and magnetic field data as inputs. The predictions show a good agreement during 7 November, up until around noon on 8 November, after which the predictions become significantly poorer. The correlations between observed and predicted log RMS Delta X is 0.77 during, 7-8 November but drops to 0.38 during 9-10 November. For RMS Delta Y the correlations for the two periods are 0.71 and 0.41, respectively. Studying the solar wind data for other L1-spacecraft (WIND and SOHO) it seems that the ACE data have a better agreement to the near-Earth solar wind during the first two days as compared to the last two days. Thus, the accuracy of the predictions depends on the location of the spacecraft and the solar wind flow direction. Another finding, for the events studied here, is that the Delta X and Delta Y models showed a very different dependence on B-z The Delta X model is almost independent of the solar wind magnetic field B-z except at times when B-z is exceptionally large or when the overall activity is low. On the contrary, the Delta Y model shows a strong dependence on B-z at all times.},
  author       = {Wintoft, P and Wik, Magnus and Lundstedt, Henrik and Eliasson, L},
  issn         = {1432-0576},
  keyword      = {solar wind-magnetosphere,magnetospheric physics,geomagnetism and,paleomagnetism,ionosphere,rapid time variations,forecasting,modeling and},
  language     = {eng},
  number       = {9},
  pages        = {3095--3101},
  publisher    = {European Geosciences Union},
  series       = {Annales Geophysicae},
  title        = {Predictions of local ground geomagnetic field fluctuations during the 7-10 November 2004 events studied with solar wind driven models},
  volume       = {23},
  year         = {2005},
}