HR: 1340h
AN: SH53B-0309    [Abstracts]
TI: Solar UV Irradiance Measurements from SUSIM UARS
AU: * Floyd, L E
EM: linton.floyd@nrl.navy.mil
AF: Interferometrics Inc., 14120 Parke Long Court, #113, Chantilly, VA 20151 United States
AU: Cook, J W
EM: john.cook@solar.nrl.navy.mil
AF: E.O. Hulburt Center for Space Research, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375 United States
AU: Herring, L C
EM: herring@susim.nrl.navy.mil
AF: Interferometrics Inc., 14120 Parke Long Court, #113, Chantilly, VA 20151 United States
AB: The Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) aboard the Upper Atmosphere Research Satellite (UARS) has measured the solar UV irradiance since October 1991. This 13 year time period includes a secondary maximum of solar cycle 22, the ensuing solar minimum, the maximum of solar cycle 23, and its declining phase. SUSIM maintains the calibration of its changing responsivity through a combination of measurements of four stable onboard deuterium calibration lamps and measurements of infrequently exposed reference channels. The wavelength-dependent UV irradiance time series exhibit two dominant periodicities, that of solar rotation (27~days) and solar cycle (11~years). The solar cycle variation of the UV irradiance was similar for solar cycles~22 and 23: about 55% at Ly-$\alpha$, about 7% at 205~nm, and less than 1% above 300~nm. The SUSIM measurements are compared with other coincident measurements including those of SOLSTICE over a similar time period and with the Mg~II core-to-wing ratio index. Prospects and requirements for continued and possibly improved monitoring of the solar UV irradiance are discussed.
UR: http://solarwww.nrl.navy.mil/susim\_uars.html
DE: 7536 Solar activity cycle (2162)
DE: 7537 Solar and stellar variability
DE: 7538 Solar irradiance
DE: 7549 Ultraviolet emissions
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting