0310 Airglow and aurora; 0358 Thermosphere--energy deposition
Abstract :
[en] Auroral emissions are observed in 3 separate Far-Ultraviolet (FUV) wavelength regimes by IMAGE. The Wideband Imaging Camera (WIC) is sensitive mainly to N[SUB]2[/SUB] LBH and N I emissions in the 140-190-nm range, while the Spectrographic Imager (SI) spectrally separates the OI 135.6-nm emission and Doppler shifted hydrogen emissions of the proton aurora at 121.8 nm. The brightness of the N[SUB]2[/SUB] LBH and OI 135.6-nm emissions depend in part on the spectrum and total energy flux of incoming electrons, and on the height-density profile of the respective species, and O[SUB]2[/SUB]. Due mainly to these atmospheric factors, the ratio of the N[SUB]2[/SUB] and OI emissions depends strongly on the characteristic energy of precipitating electrons which, once estimated, can in turn be used to calculate the total energy flux. The proton aurora generates secondary electrons, which excite additional emissions of N[SUB]2[/SUB] and OI. It is not possible to absolutely determine either the total proton energy flux or the characteristic proton energy (<E[SUB]p[/SUB]>) with a single proton imaging channel. However, the proton-induced N[SUB]2[/SUB] and OI emissions depend mainly on the total proton energy flux, so reasonable estimates of <E[SUB]p[/SUB]> can be used in the calculation of proton energy input. Ground-based or in-situ observations of proton energies can help in this determination. With accurate corrections for N[SUB]2[/SUB] and OI airglow emissions, and formulae such as those provided by Robinson et al. [1987], IMAGE FUV can provide global maps of height-integrated conductivity (conductance) in the auroral oval. It is also possible to examine the degree to which the proton aurora contributes to enhanced conductance on a global scale. The promise of providing these conductances using IMAGE's real-time capabilities will be discussed. Robinson, R. M., R. R. Vondrak, K. Miller, T. Dabbs, and D. Hardy, On Calculating Ionospheric Conductances from the Flux and Energy of Precipitating Electrons, J. Geophys. Res., 92, 2566, 1987.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Immel, T. J.; Space Sciences Laboratory University of California Berkeley , Centennial Drive at Grizzly Peak, Berkeley, CA 94720-7450 United States
Mende, S. B.; Space Sciences Laboratory University of California Berkeley , Centennial Drive at Grizzly Peak, Berkeley, CA 94720-7450 United States
Frey, H. U.; Space Sciences Laboratory University of California Berkeley , Centennial Drive at Grizzly Peak, Berkeley, CA 94720-7450 United States
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Hubert, Benoît ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
This website uses cookies to improve user experience. Read more
Save & Close
Accept all
Decline all
Show detailsHide details
Cookie declaration
About cookies
Strictly necessary
Performance
Strictly necessary cookies allow core website functionality such as user login and account management. The website cannot be used properly without strictly necessary cookies.
This cookie is used by Cookie-Script.com service to remember visitor cookie consent preferences. It is necessary for Cookie-Script.com cookie banner to work properly.
Performance cookies are used to see how visitors use the website, eg. analytics cookies. Those cookies cannot be used to directly identify a certain visitor.
Used to store the attribution information, the referrer initially used to visit the website
Cookies are small text files that are placed on your computer by websites that you visit. Websites use cookies to help users navigate efficiently and perform certain functions. Cookies that are required for the website to operate properly are allowed to be set without your permission. All other cookies need to be approved before they can be set in the browser.
You can change your consent to cookie usage at any time on our Privacy Policy page.