Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM
Cluster/EDI electron drift observations above the Northern and Southern polar cap areas for more than seven and a half years (2001–2008) have been used to derive a statistical model of the high-latitude electric potential distribution for summer conditions. Based on potential pattern for differe...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2009-08-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/27/3077/2009/angeo-27-3077-2009.pdf |
| _version_ | 1818550366192533504 |
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| author | M. Förster Y. I. Feldstein S. E. Haaland S. E. Haaland L. A. Dremukhina L. I. Gromova A. E. Levitin |
| author_facet | M. Förster Y. I. Feldstein S. E. Haaland S. E. Haaland L. A. Dremukhina L. I. Gromova A. E. Levitin |
| author_sort | M. Förster |
| collection | DOAJ |
| description | Cluster/EDI electron drift observations above the Northern and Southern polar
cap areas for more than seven and a half years (2001–2008) have been used
to derive a statistical model of the high-latitude electric potential
distribution for summer conditions.
Based on potential pattern for different orientations of the interplanetary
magnetic field (IMF) in the GSM y-z-plane, basic convection pattern (BCP)
were derived, that represent the main characteristics of the electric
potential distribution in dependence on the IMF.
The BCPs comprise the IMF-independent potential distribution as well as
patterns, which describe the dependence on positive and negative IMF<I>B<sub>z</sub></I> and
IMF<I>B<sub>y</sub></I> variations.
The full set of BCPs allows to describe the spatial and temporal variation
of the high-latitude electric potential (ionospheric convection) for any
solar wind IMF condition near the Earth's magnetopause within reasonable ranges.
The comparison of the Cluster/EDI model with the IZMEM ionospheric convection
model, which was derived from ground-based magnetometer observations, shows
a good agreement of the basic patterns and its variation with the IMF.
According to the statistical models, there is a two-cell antisunward convection
within the polar cap for northward IMF<I>B<sub>z</sub></I>+≤2 nT, while for increasing
northward IMF<I>B<sub>z</sub></I>+ there appears a region of sunward convection within the
high-latitude daytime sector, which assumes the form of two additional
cells with sunward convection between them for IMF<I>B<sub>z</sub></I>+≈4–5 nT.
This results in a four-cell convection pattern of the high-latitude convection.
In dependence of the ±IMF<I>B<sub>y</sub></I> contribution during sufficiently strong
northward IMF<I>B<sub>z</sub></I> conditions, a transformation to three-cell convection
patterns takes place. |
| first_indexed | 2024-12-12T08:45:30Z |
| format | Article |
| id | doaj.art-ce4b14ed69834367bb78ad370f20db2a |
| institution | Directory Open Access Journal |
| issn | 0992-7689 1432-0576 |
| language | English |
| last_indexed | 2024-12-12T08:45:30Z |
| publishDate | 2009-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Annales Geophysicae |
| spelling | doaj.art-ce4b14ed69834367bb78ad370f20db2a2022-12-22T00:30:35ZengCopernicus PublicationsAnnales Geophysicae0992-76891432-05762009-08-01273077308710.5194/angeo-27-3077-2009Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEMM. Förster0Y. I. Feldstein1S. E. Haaland2S. E. Haaland3L. A. Dremukhina4L. I. Gromova5A. E. Levitin6Helmholtz-Zentrum Potsdam, GFZ German Research Centre for Geosciences, 14473 Potsdam, GermanyInstitute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Troitsk, RussiaMax-Planck-Institut für Sonnensystemforschung, Lindau-Katlenburg, GermanyDepartment of Physics and Technology, University of Bergen, NorwayInstitute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Troitsk, RussiaInstitute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Troitsk, RussiaInstitute of Terrestrial Magnetism, Ionosphere, and Radiowave Propagation, Troitsk, RussiaCluster/EDI electron drift observations above the Northern and Southern polar cap areas for more than seven and a half years (2001–2008) have been used to derive a statistical model of the high-latitude electric potential distribution for summer conditions. Based on potential pattern for different orientations of the interplanetary magnetic field (IMF) in the GSM y-z-plane, basic convection pattern (BCP) were derived, that represent the main characteristics of the electric potential distribution in dependence on the IMF. The BCPs comprise the IMF-independent potential distribution as well as patterns, which describe the dependence on positive and negative IMF<I>B<sub>z</sub></I> and IMF<I>B<sub>y</sub></I> variations. The full set of BCPs allows to describe the spatial and temporal variation of the high-latitude electric potential (ionospheric convection) for any solar wind IMF condition near the Earth's magnetopause within reasonable ranges. The comparison of the Cluster/EDI model with the IZMEM ionospheric convection model, which was derived from ground-based magnetometer observations, shows a good agreement of the basic patterns and its variation with the IMF. According to the statistical models, there is a two-cell antisunward convection within the polar cap for northward IMF<I>B<sub>z</sub></I>+≤2 nT, while for increasing northward IMF<I>B<sub>z</sub></I>+ there appears a region of sunward convection within the high-latitude daytime sector, which assumes the form of two additional cells with sunward convection between them for IMF<I>B<sub>z</sub></I>+≈4–5 nT. This results in a four-cell convection pattern of the high-latitude convection. In dependence of the ±IMF<I>B<sub>y</sub></I> contribution during sufficiently strong northward IMF<I>B<sub>z</sub></I> conditions, a transformation to three-cell convection patterns takes place.https://www.ann-geophys.net/27/3077/2009/angeo-27-3077-2009.pdf |
| spellingShingle | M. Förster Y. I. Feldstein S. E. Haaland S. E. Haaland L. A. Dremukhina L. I. Gromova A. E. Levitin Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM Annales Geophysicae |
| title | Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM |
| title_full | Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM |
| title_fullStr | Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM |
| title_full_unstemmed | Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM |
| title_short | Magnetospheric convection from Cluster EDI measurements compared with the ground-based ionospheric convection model IZMEM |
| title_sort | magnetospheric convection from cluster edi measurements compared with the ground based ionospheric convection model izmem |
| url | https://www.ann-geophys.net/27/3077/2009/angeo-27-3077-2009.pdf |
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