Decreases in atomic hydrogen over the summer pole: Evidence for dehydration from polar mesospheric clouds?

David E. Siskind, Daniel R. Marsh, Martin G. Mlynczak, F. Javier Martin-Torres, James M. Russell

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Observations from the Sounding of the Atmosphere with Broadband Emission Radiometry (SABER) instrument on the NASA/Thermospheric Ionosphere Mesosphere Energetics and Dynamics satellite show a surprising decrease in the inferred atomic hydrogen (H) over the polar regions in the lowermost thermosphere during the summer. This contrasts with predictions by global models that H should peak in this region at this time. We suggest the decrease is a consequence of the sequestering of the water vapor by the formation of polar mesospheric clouds (PMCs) that redistributes the H2O thus reducing the chemical source of H. This decrease is more pronounced in the Northern rather than the Southern summer which is roughly consistent with the known morphology of PMCs. A model calculation which includes a PMC parameterization gives good qualitative agreement with the data suggesting that this process should be considered in global models of the coupling between the middle and upper atmosphere.

Original languageEnglish
Pages (from-to)L13809
JournalGeophysical Research Letters
Volume35
Issue number13
DOIs
Publication statusPublished - 1 Jul 2008

Keywords

  • Atmospheric Composition and Structure: Thermosphere: composition and chemistry
  • Atmospheric Composition and Structure: Middle atmosphere: composition and chemistry
  • Atmospheric Composition and Structure: Middle atmosphere: constituent transport and chemistry (3334)
  • Atmospheric Composition and Structure: Chemical kinetic and photochemical properties

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