Journal ArticleDOI
EUVAC: A solar EUV Flux Model for aeronomic calculations
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In this article, a new solar Extreme Ultraviolet (EUV) flux model for aeronomic calulations is presented, which is based on the measured F74113 solar EUV reference spectrum.Abstract:
This paper presents a new solar Extreme Ultraviolet (EUV) flux model for aeronomic calulations (EUVAC), which is based on the measured F74113 solar EUV reference spectrum. The model provides fluxes in the 37 wavelength bins that are in widespread use. This paper also presents cross sections to be used with the EUVAC flux model to calculate photoionization rates. The flux scaling for solar activity is accomplished using a proxy-based on the F10.7 index and its 81-day average together with the measured solar flux variation from the EUVS instrument on the Atmosphere Explorer E satellite. This new model produces 50-575 A integrated EUV fluxes in good agreement with rocket observations. The solar cycle variation of the chromospheric fluxes agrees well with the measured variation of the Lyman alpha flux between 1982 and 1988. In addition, the theoretical photoelectron fluxes, calculated using the new EUV flux model, are in good agreement with the solar minimum photoelectron fluxes from the Atmosphere Explorer E satellite and also with the solar maximum photoelectron fluxes from the Dynamics Explorer satellite. Its relative simplicity coupled with its ability to reproduce the 50-575 A solar EUV flux as well as the measured photoelectron spectrum makes the model well suited for aeronomic applications. However, EUVAC is not designed to accurately predict the solar flux variability for numerous individual lines.read more
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Journal ArticleDOI
Solar EUV Experiment (SEE): Mission overview and first results
Thomas N. Woods,Francis G. Eparvier,Scott M. Bailey,Phillip C. Chamberlin,Judith Lean,Gary J. Rottman,Stanley C. Solomon,W. Kent Tobiska,D. Woodraska +8 more
TL;DR: The Solar EUV Experiment (SEE) is one of four scientific instruments on the NASA Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) spacecraft, which has been simultaneously observing the Sun and Earth's upper atmosphere since January 2002 as discussed by the authors.
Journal ArticleDOI
Sami2 is Another Model of the Ionosphere (SAMI2): A new low-latitude ionosphere model
TL;DR: A low-latitude ionospheric model has been developed at the Naval Research Laboratory: Sami2 is Another Model of the Ionosphere (SAMI2) as discussed by the authors, which treats the dynamic plasma and chemical evolution of seven ion species in the altitude range ∼ 100 km to several thousand kilometers.
Journal ArticleDOI
An empirical model of the Earth's horizontal wind fields: HWM07
Douglas P. Drob,J. T. Emmert,Geoff Crowley,J. M. Picone,Gordon G. Shepherd,Wilbert R. Skinner,Paul B. Hays,Rick J. Niciejewski,Miguel Larsen,Chiao-Yao She,John W. Meriwether,G. Hernandez,Martin J. Jarvis,D. P. Sipler,Craig A. Tepley,M. S. O'Brien,J. R. Bowman,Qian Wu,Yasuhiro Murayama,Seiji Kawamura,Iain M. Reid,Robert A. Vincent +21 more
TL;DR: The Horizontal Wind Model (HWM07) as mentioned in this paper provides a statistical representation of the horizontal wind fields of the Earth's atmosphere from the ground to the exosphere (0-500 km).
Journal ArticleDOI
The SOLAR2000 empirical solar irradiance model and forecast tool
W. Kent Tobiska,Thomas N. Woods,Frank Eparvier,Rodney Viereck,L. E. Floyd,D. Bouwer,Gary J. Rottman,Oran R. White +7 more
TL;DR: SOLAR2000 captures the essence of historically measured solar irradiances and this expands knowledge about the quiet and variable Sun including its historical envelope of variability.
Journal ArticleDOI
A far ultraviolet imager for the International Solar-Terrestrial Physics Mission
Marsha R. Torr,Douglas G. Torr,Muamer Zukic,R. B. Johnson,J. Ajello,Peter M. Banks,K. Clark,Kelly Stefano Cole,Charles E. Keffer,George K. Parks,Bruce T. Tsurutani,James F. Spann +11 more
TL;DR: The Ultraviolet Imager for the Global Geospace Sciences portion of the International Solar-Terrestrial Physics (IGSSP) program as discussed by the authors has been used to image the auroral oval and polar cap.
References
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Journal ArticleDOI
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Journal ArticleDOI
Ionization frequencies for major thermospheric constituents as a function of solar cycle 21
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Journal ArticleDOI
Solar ultraviolet irradiance variations: A review
TL;DR: In this article, a review of solar ultraviolet irradiance variations over both short and long time scales are reviewed, with emphasis on their connection to solar magnetic activity. But neither rocket nor satellite measurements have yet been made with sufficient accuracy and regularity to establish unequivocally the nature of the variability over the longer time of the 11-year solar cycle.
Journal ArticleDOI
Ionization frequencies for solar cycle 21: Revised
Marsha R. Torr,D. G. Torr +1 more
TL;DR: In this paper, a redetermination of the most important ionization frequencies using the revised solar fluxes is reported, and the impact is more significant at solar maximum, amounting to a reduction of 12-21 percent in the ionization frequency of the major terrestrial thermospheric constituents for solar-minimum conditions and 21-33 percent for solar maximum conditions.