Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Geocoronal H alpha intensity measurements using the Wisconsin H alpha Mapper Fabry-Perot facility
Autore:
Nossal, S; Roesler, FL; Bishop, J; Reynolds, RJ; Haffner, M; Tufte, S; Percival, J; Mierkiewicz, EJ;
Indirizzi:
Univ Wisconsin, Dept Phys, Madison, WI 53706 USA Univ Wisconsin Madison WI USA 53706 sin, Dept Phys, Madison, WI 53706 USA USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA USN Washington DC USA 20375 lburt Ctr Space Res, Washington, DC 20375 USA Univ Wisconsin, Dept Astron, Madison, WI 53706 USA Univ Wisconsin MadisonWI USA 53706 n, Dept Astron, Madison, WI 53706 USA Univ Wisconsin, Astron Spatiale Lab, Madison, WI 53706 USA Univ WisconsinMadison WI USA 53706 n Spatiale Lab, Madison, WI 53706 USA Univ Wisconsin, Dept Atmospher & Ocean Sci, Madison, WI 53706 USA Univ Wisconsin Madison WI USA 53706 er & Ocean Sci, Madison, WI 53706 USA
Titolo Testata:
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
fascicolo: A4, volume: 106, anno: 2001,
pagine: 5605 - 5615
SICI:
0148-0227(20010401)106:A4<5605:GHAIMU>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
ANNULAR-SUMMING SPECTROSCOPY; ATOMIC-HYDROGEN; LINE-PROFILES; THERMOSPHERE; EMISSION; MODEL; EXCITATION; MESOSPHERE; EXOSPHERE; DENSITY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Nossal, S Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA Univ Wisconsin 1150 Univ Ave Madison WI USA 53706 , WI 53706 USA
Citazione:
S. Nossal et al., "Geocoronal H alpha intensity measurements using the Wisconsin H alpha Mapper Fabry-Perot facility", J GEO R-S P, 106(A4), 2001, pp. 5605-5615

Abstract

The Wisconsin Her Mapper (WHAM), a remotely operable, semi-automated Fabry-Perot located at Kitt Peak Observatory, has been making an all-sky survey of interstellar hydrogen Balmer alpha (H alpha) emissions since 1997. Usingthe annular summing spectroscopy technique, WHAM has acquired similar to 37,000 spectra to date, spanning almost 100 nights of observations. Since all of the galactic emission spectral data contain the terrestrial H alpha (6562.7 Angstrom) emission line, these measurements constitute a rich source of geocoronal data for investigating natural variability in the upper atmosphere. The WHAM observations also serve as a benchmark for comparison with future data. Analysis of the first year of WHAM data shows only small day-to-day variations after shadow altitude variations are taken into account. For example, at shadow altitudes of 2000 and 3000 km, the RMS scatter is within approximately +/- 20%; this variability is expected to be reduced with accurate accounting of the smaller-scale effects of observational slant path, zenith angle, and azimuth on the H alpha intensity. This result is consistent with past midlatitude Wisconsin data sets but different from observations made by other observers and instruments at the low-latitude Arecibo site. The multiple viewing geometries of the observations provide stringent modeling constraints, useful in testing current modeling capabilities. Modeling of the WHAM data with a global nonisothermal resonance radiation transport code (lyao_rt) indicates that the signal-to-noise of the data is sufficient to determine relative variations in upper atmospheric atomic hydrogen column densities to better than 5%. This paper describes the WHAM aeronomy program and its observational scheme, analysis procedures, and results fromdata taken in 1997. Case study comparisons are made with past data sets and with predictions from the lyao_rt resonant radiation transport modeling code of Bishop [1999].

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 04/04/20 alle ore 12:12:16