Journal cover Journal topic
Annales Geophysicae An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

IF value: 1.490
IF1.490
IF 5-year value: 1.445
IF 5-year
1.445
CiteScore value: 2.9
CiteScore
2.9
SNIP value: 0.789
SNIP0.789
IPP value: 1.48
IPP1.48
SJR value: 0.74
SJR0.74
Scimago H <br class='widget-line-break'>index value: 88
Scimago H
index
88
h5-index value: 21
h5-index21
Volume 27, issue 3
Ann. Geophys., 27, 1343–1352, 2009
https://doi.org/10.5194/angeo-27-1343-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Ninth International Conference on Substorms (ICS9)

Ann. Geophys., 27, 1343–1352, 2009
https://doi.org/10.5194/angeo-27-1343-2009
© Author(s) 2009. This work is distributed under
the Creative Commons Attribution 3.0 License.

  31 Mar 2009

31 Mar 2009


Dipole tilt effects in plasma sheet By: statistical model and extreme values

A. A. Petrukovich A. A. Petrukovich
  • Space Research Institute, 84/32 Profsoyuznaya st., Moscow, 117997, Russia

Abstract. With 11 years of Geotail measurements we construct a model of plasma sheet By, depending on IMF By, coordinates X,Y and geodipole tilt angle. At midnight and pre-midnight local times By is positively correlated with tilt (positive in summer). Thus in summer By is shifted towards positive values and in winter towards negative values, so that up to several nT could be added to the IMF influence. The dawn side plasma sheet By generally does not exhibit any tilt dependence, but within 15 RE the weaker negative correlation with tilt was revealed. The tilt dependence is just a useful parametrization and several mechanisms actually affecting plasma sheet By were previously suggested. In particular, similar coupling between tilt and IMF By was earlier found in the ionospheric convection patterns. Besides this average response, extreme By (|By|>5 nT, By>IMF By) were often observed (up to 20–25% of cases during solar maximum and in the pre-midnight sector within 20 RE). They can not be explained by our statistical model and are preliminary interpreted as an "over-reaction" of the magnetosphere in some individual events. Large By field radically changes dynamics of the current sheet and has to be taken into account during substorm-related studies.

Publications Copernicus
Download
Citation