Excitation of mid-latitude oxygen airglow emission at 844.6 nm

Details Excitation of mid-latitude oxygen airglow emission at 844.6 nm Excitation of mid-latitude oxygen airglow emission at 844.6 nm

Dec 2007

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007agufmsa41a0267w&link_type=abstract

American Geophysical Union, Fall Meeting 2007, abstract #SA41A-0267

Physics

0310 Airglow And Aurora, 0355 Thermosphere: Composition And Chemistry, 2443 Midlatitude Ionosphere, 3360 Remote Sensing, 3394 Instruments And Techniques

Scientific paper

Photoelectron (PE) impact on thermospheric oxygen atoms is a major source of OI 8446 Å\ emission excitation at mid-latitudes. However, historical discrepancies between observed twilight emission brightnesses and photoelectron (PE) model predictions have not only prompted speculation regarding secondary sources of excitation but also precluded the use of observed brightness as a much-needed diagnostic of thermospheric O density. In an effort to improve understanding of the physical mechanisms responsible for its excitation, we present new photometric measurements of twilight OI 8446 Å\ emission brightness acquired from Arecibo Observatory, together with calculations of expected brightness from PE-impact excitation as well as a key secondary excitation source: radiative recombination of O+ ions. Although the 8446 Å\ brightness data are fully consistent with a dominant PE impact excitation source during winter, the new data also confirm an earlier report of excess early morning brightness with respect to PE models which use a tilted-dipole approximation to the geomagnetic field. We demonstrate that the poor agreement arises simply as a consequence of inaccurate model specification of the geomagnetic field configuration and associated conjugate point location. Using the IGRF geomagnetic field model to refine Arecibo's conjugate point location specified in the Field Line Interhemispheric Plasma (FLIP) PE model yields significantly improved agreement between the modeled and observed brightness decay profiles during both morning and evening twilight intervals. This simple geometric resolution to the historical discrepancy establishes the unique favorability of 8446 Å\ airglow for mid-laittude thermospheric remote sensing.

Affiliated with

Also associated with

No associations

Rating

Excitation of mid-latitude oxygen airglow emission at 844.6 nm does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Excitation of mid-latitude oxygen airglow emission at 844.6 nm, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Excitation of mid-latitude oxygen airglow emission at 844.6 nm will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1414224