Retrievals of nighttime electron density from Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission Global Ultraviolet Imager (GUVI) measurements

R. DeMajistre, L. J. Paxton, D. Morrison, J. H. Yee, Larisa Petrovna Goncharenko, A. B. Christensen

Research output: Contribution to journalArticle

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Abstract

In this work we will present a method for retrieving nighttime electron density profiles from OI 135.6 nm limb emissions measured by the Global Ultraviolet Imager (GUVI) aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission spacecraft. The primary mechanism for 135.6 nm radiance in the nighttime thermosphere is recombination of O + ions, and the volume emission rate is approximately proportional to the square of the electron density. Herein we describe a two-step inversion method in which we first determine the volume emission rate as a function of altitude from the radiance measurements and then use the inferred volume emission rates to determine the electron density profile. There are two important factors that we have addressed in constructing the retrieval algorithms for this problem. First, the GUVI instrument was primarily designed for day side measurements. Consequently, the signal levels on the night side are very low, and our retrieval algorithms must therefore be able to function in regions where the signals are weak. Second, since we must take the square root of the volume emission rate, it must be everywhere positive in order for the electron density to be deduced. For this reason, we have imposed nonnegativity constraints (using the methods described by Menke [1989]) on what might otherwise be discrete linear retrievals of volume emission rate. After describing the retrieval method we present an error analysis and a preliminary comparison with coincident measurements by incoherent scatter radars (ISRs). In general, the retrieved electron densities from the GUVI data agree well with the ISR data, although more coincident measurements would increase our confidence in the resulting electron density profiles.

Original languageEnglish
Article numberA05305
JournalJournal of Geophysical Research: Space Physics
Volume109
Issue numberA5
DOIs
Publication statusPublished - Jan 1 2004

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Ionosphere
mesosphere
thermosphere
Image sensors
electron density
ionospheres
retrieval
Carrier concentration
ionosphere
energetics
electrons
electron density profiles
radiance
error analysis
limbs
methodology
night
Error analysis
recombination
Spacecraft

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Oceanography
  • Forestry
  • Aquatic Science
  • Ecology
  • Condensed Matter Physics
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Physical and Theoretical Chemistry
  • Polymers and Plastics
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Materials Chemistry
  • Palaeontology

Cite this

Retrievals of nighttime electron density from Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission Global Ultraviolet Imager (GUVI) measurements. / DeMajistre, R.; Paxton, L. J.; Morrison, D.; Yee, J. H.; Goncharenko, Larisa Petrovna; Christensen, A. B.

In: Journal of Geophysical Research: Space Physics, Vol. 109, No. A5, A05305, 01.01.2004.

Research output: Contribution to journalArticle

DeMajistre, R. ; Paxton, L. J. ; Morrison, D. ; Yee, J. H. ; Goncharenko, Larisa Petrovna ; Christensen, A. B. / Retrievals of nighttime electron density from Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission Global Ultraviolet Imager (GUVI) measurements. In: Journal of Geophysical Research: Space Physics. 2004 ; Vol. 109, No. A5.
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