Surname: Wright
First Name: John William
Status= other
Institution: NGDC (retired)
E-mail: bwright@ngdc.noaa.gov
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Title: 
SWIFT - ITCI: Space Weather Ionospheric Forecasting Tools – an Ionosonde 
Thermospheric Composition Index
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Authors: 
J W Wright and R O Conkright
National Geophysical Data Center, NOAA, Boulder Colorado, 80301 USA
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Abstract: 
We address the need for an easily observable indicator of
thermospheric state, and particularly, one sensitive to the
neutral concentration ratio, [O]/[N2]. There is a firm basis to expect that the 
sunrise increase of foF2 might provide an index for [O]/[N2]. We present the 
global morphology of an index defined from the rate of change of foF2^2 with 
cos(solar zenith angle) after normalization by the F10.7 solar flux. It displays 
many known features of thermospheric [O]/[N2], including seasonal and geographic 
variability according to ESRO4 satellite data and the MSIS-90 model, and (in an 
example) magnetic storm dependences.
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Discipline Category: Thermosphere