elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Magnetic states of the ionosphere of Venus observed by Venus Express

Angsmann, A. and Fränz, M. and Dubinin, E. and Woch, J. and Barabash, S. and Zhang, T. L. and Motschmann, Uwe (2011) Magnetic states of the ionosphere of Venus observed by Venus Express. Planetary and Space Science, 59, pp. 327-337. Elsevier. DOI: 10.1016/j.pss.2010.12.004 ISSN 0032-0633

Full text not available from this repository.

Abstract

Strong ultraviolet radiation from the Sun ionizes the upper atmosphere of Venus, creating a dense ionosphere on the day side of the planet. In contrast to Earth, the ionosphere of Venus is not protected against the solar wind by a magnetic field. However, the interaction between charged ionospheric particles and the solar wind dynamic and magnetic pressure creates a pseudo-magnetosphere which deflects the solar wind flow around the planet (Schunk and Nagy,1980). The combination of changing solar radiation and solar wind intensities leads to a highly variable structure and plasma composition of the ionosphere. The instrumentation of the Venus Express spacecraft allows to measure the magneticfield (MAG experiment) as well as the electronenergy spectrum and the ioncomposition (ASPERA-4 experiment) of the upper ionosphere and ionopause. In contrast to the earlier Pioneer Venus Orbiter (PVO) measurements which were conducted during solar maximum,the solar activity was very low in the period 2006–2009. A comparison with PVO allows for ani nvestigation ofi onospheric properties under different solar wind and EUV radiation conditions. Observations of MAG and ASPERA have been analyzed to determine the positions of the photoelectron boundary (PEB) and the ‘‘magnetopause’’ and their dependence on the solar zenith angle (SZA). The PEB was determined using the ELS observations of ionospheric photoelectrons, which can be identified by their specific energyrange. It is of particular interest to explore the different magnetic states of the ionosphere, since these influence the local plasma conductivity, currents and probably the escape of electrons and ions. The penetration of magnetic fields into the ionosphere depends on the external conditions as well as on the ionospheric properties. By analyzing a large number of orbits, using a combination of two different methods, we define criteria to distinguish between the so-called magnetized and unmagnetized ionospheric states. Furthermore,we confirm that the average magnetic field inside the ionosphere shows a linear dependence on the magnetic field in the region directly above the PEB.

Item URL in elib:https://elib.dlr.de/70125/
Document Type:Article
Title:Magnetic states of the ionosphere of Venus observed by Venus Express
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Angsmann, A.Max Planck Institute for Solar System Research, Katlenburg-Lindau, GermanyUNSPECIFIED
Fränz, M.Max Planck Institute for Solar System Research, Katlenburg-Lindau, GermanyUNSPECIFIED
Dubinin, E.Max Planck Institute for Solar System Research, Katlenburg-Lindau, GermanyUNSPECIFIED
Woch, J.Max Planck Institute for Solar System Research, Katlenburg-Lindau, GermanyUNSPECIFIED
Barabash, S. Swedish Institute of Space Physics, Kiruna, SwedenUNSPECIFIED
Zhang, T. L.Space Research Institute of the Austrian Academy of Sciences, Graz, AustriaUNSPECIFIED
Motschmann, UweInstitute for Theoretical Physics,Technical University of Braunschweig, Germany; uwe.motschmann (at) dlr.de UNSPECIFIED
Date:2011
Journal or Publication Title:Planetary and Space Science
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:Yes
In ISI Web of Science:Yes
Volume:59
DOI :10.1016/j.pss.2010.12.004
Page Range:pp. 327-337
Publisher:Elsevier
ISSN:0032-0633
Status:Published
Keywords:Venus, Ionosphere, Magnetic field
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W EW - Erforschung des Weltraums
DLR - Research area:Space
DLR - Program:W EW - Erforschung des Weltraums
DLR - Research theme (Project):W - Vorhaben Venus Express (old)
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Extrasolar Planets and Atmospheres
Deposited By: Brumm, Laura-Maria
Deposited On:20 Jun 2011 11:40
Last Modified:26 Mar 2013 13:29

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.