Umeå universitets logga

umu.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
The tailward flow of energetic neutral atoms observed at Mars
Institutet för rymdfysik (IRF).
Visa övriga samt affilieringar
2008 (Engelska)Ingår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 113, artikel-id E12012Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The ASPERA-3 experiment on Mars Express provides the first measurements of energetic neutral atoms (ENAs) from Mars. These measurements are used to study the global structure of the interaction of the solar wind with the Martian atmosphere. In this study we describe the tailward ENA flow observed at the nightside of Mars. After characterizing energy spectra of hydrogen ENA signals, we present composite images of the ENA intensities and compare them to theoretical predictions (empirical and MHD models). We find that the tailward flow of hydrogen ENAs is mainly generated by shocked solar wind protons. Despite intensive search, no oxygen ENAs above the instrument threshold are detected. The results challenge existing plasma models and constrain the hydrogen exospheric densities and atmospheric hydrogen and oxygen loss rates at low solar activity.

Ort, förlag, år, upplaga, sidor
Washington: American Geophysical Union (AGU), 2008. Vol. 113, artikel-id E12012
Nyckelord [en]
solar-wind interaction, subsolar ENA jet, 1st-ENA observations, Aspera-3 observations, upper atmosphere, charge-exchange, express mission, space plasmas, hydrogen, distributions
Nationell ämneskategori
Geokemi Geofysik
Identifikatorer
URN: urn:nbn:se:umu:diva-3361DOI: 10.1029/2008JE003139ISI: 000262043600001OAI: oai:DiVA.org:umu-3361DiVA, id: diva2:142028
Tillgänglig från: 2008-09-04 Skapad: 2008-09-04 Senast uppdaterad: 2018-06-09Bibliografiskt granskad
Ingår i avhandling
1. Numerical modelling of ENAs from stellar wind interactions
Öppna denna publikation i ny flik eller fönster >>Numerical modelling of ENAs from stellar wind interactions
2008 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Energetic neutral atoms (ENAs) are produced whenever a stellar wind encounters a neutral atmosphere. If a stellar wind proton comes sufficiently close to a neutral a charge-exchange reaction may take place, transforming the proton into an ENA. Unaffected by magnetic and electric fields, ENAs provide an opportunity for global imaging of stellar wind interactions.

This thesis presents methods and results of numerical modelling of stellar wind interactions. In particular it treats in depth production of ENAs at comets, Mars and the extrasolar planet HD 209458b.

Sufficiently accurate numerical models of stellar wind interactions require extensive computations. Parallel computing has therefore been used throughout the work, both for fluid and particle simulations of space plasmas. This thesis describes the use of a general simulation tool, providing parallel computing for space plasma simulations.

The thesis presents estimations of the magnitude and morphology of the ENA production at comets and HD 209458b. It compares the results obtained with observations and analyzes them in the light of ENA production at similar objects. Also, simulated ENA images for Mars were produced and compared to observations.

Ort, förlag, år, upplaga, sidor
Kiruna: Institutet för rymdfysik (IRF), 2008. s. 52
Serie
IRF Scientific Report, ISSN 0284-1703 ; 297
Nyckelord
Space physics, Space technology, Astrophysics
Nationell ämneskategori
Rymd- och flygteknik
Identifikatorer
urn:nbn:se:umu:diva-1804 (URN)978-91-977255-5-2 (ISBN)
Disputation
2008-09-26, Aulan, Institutet för rymdfysik, Etian 100, Kiruna, 10:00
Opponent
Handledare
Tillgänglig från: 2008-09-04 Skapad: 2008-09-03Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Förlagets fulltext

Person

Holmström, MatsBarabash, StasFutaana, Yoshifumi

Sök vidare i DiVA

Av författaren/redaktören
Holmström, MatsBarabash, StasFutaana, Yoshifumi
I samma tidskrift
Journal of Geophysical Research
GeokemiGeofysik

Sök vidare utanför DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetricpoäng

doi
urn-nbn
Totalt: 321 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf