Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere

Details Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere

Jul 1997

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1997jgr...10214485s&link_type=abstract

Journal of Geophysical Research, Volume 102, Issue A7, p. 14485-14498

Physics

6

Atmospheric Composition And Structure: Airglow And Aurora, Atmospheric Composition And Structure: Thermosphere-Composition And Chemistry, Ionosphere: Solar Radiation And Cosmic Ray Effects, Meteorology And Atmospheric Dynamics: Thermospheric Dynamics

Scientific paper

An algorithm has been developed that rapidly and accurately calculates altitude profiles of volume excitation rates for many species of aeronomic interest. These rates may be specified as functions of solar activity (specific to the Hinteregger et al. [1981] model in this phase of the work) and solar zenith angle (SZA). The algorithm relies on an analytical expression for the g factor as a function of total vertical column density. The g factor for a given state and excitation process can be defined as the direct volume excitation rate for this process divided by the density of the species involved in the direct excitation. Modeling results from this work show that g, when expressed as a function of total vertical column density, is independent of model atmosphere within a small error illustrated in the text. The dependence within g then reduces to solar activity (characterized by F10.7) and SZA. Extensive photoelectron transport calculations have been performed that provide numerical g factors for 22 excitation processes, 3F10.7 values (75, 150, and 250), and 8 solar zenith angles (0°, 45°, 60°, 70°, 80°, 85°, 87°, and 90°). The results have been fitted with a 10 coefficient analytical expression comprised of a function based on an analytical solution to a simplified photoelectron transport equation and two Gaussian functions needed for structure because of soft X ray energy deposition. The resulting coefficients are used to calculate g factors for user-specified pairs of F10.7 and SZA by two-dimensional interpolation. By inputting a model atmosphere the corresponding volume excitation rates may also be specified. For photoionization excitation the analytic expression for the g factor is much simpler. Results presented herein include comparisons between numerical g factors and their fits, along with examples of both g factors and corresponding volume excitation rates for the purpose of showing the effects of changing solar activity and SZA. Tables are included that identify excitation processes, identify additional processes that must be considered to derive emission rates, and provide cross-section information for the electron impact processes addressed in this work.

Affiliated with

Also associated with

No associations

Rating

Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere 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 Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Analytical representation of <formula>g factors for rapid, accurate calculation of excitation rates in the dayside thermosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1414450