HR: 11:20h
AN: SA32B-01 INVITED     [Abstracts]
TI: Solar Ultraviolet Irradiance Variability During the TIMED Mission
AU: Woods, T N
EM: tom.woods@lasp.colorado.edu
AF: Lab. for Atmospheric and Space Physics / Univ. of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: Eparvier, F G
EM: frank.eparvier@lasp.colorado.edu
AF: Lab. for Atmospheric and Space Physics / Univ. of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AU: * Chamberlin, P
EM: phil.chamberlin@lasp.colorado.edu
AF: Lab. for Atmospheric and Space Physics / Univ. of Colorado, 1234 Innovation Dr., Boulder, CO 80303 United States
AB: The TIMED satellite was launched in December 2001 near solar cycle maximum. The solar activity remained at solar maximum conditions during 2002 and has declined to low-moderate activity in 2003 and 2004, but this later period included several large solar storm periods in June 2003, October 2003, and July 2004. As part of the TIMED mission objective to study the energetics of the upper atmosphere, the Solar EUV Experiment (SEE) aboard TIMED measures the solar extreme ultraviolet (EUV) energy input. The SEE instrument is measuring the solar UV irradiance with a 3% duty cycle (3 minutes each orbit) and with a spectral resolution of 0.4 nm between 27 and 194 nm and with 7-10 nm resolution shortward of 27 nm. The solar UV irradiance varies on all time scales, seconds to years, and this variation is very dependent on wavelength. During the TIMED mission, the SEE instrument has observed over 200 flares which last from minutes to hours, over 35 solar rotations which have a period of about 27 days, and maximum to low-moderate conditions during the current 11-year solar cycle. The coronal emissions, such as the Fe XVI 33.5 nm emission and X-rays, vary the most, with variations of a factor of 30 for the large flares, a factor of 2 for solar rotation, and a factor of 5 during the TIMED mission (2 years). The transition region emissions, such as the H I 121.6 nm and He II 30.4 nm emissions, vary less, with variations of a factor of 1.5 for the large flares, a factor of 1.2 for solar rotation and a factor of 1.6 during the TIMED mission. The chromospheric and photospheric emissions vary even less. The variations of the solar UV irradiance shortward of 194 nm will be discussed in the context of the TIMED mission.
UR: http://lasp.colorado.edu/see/
DE: 7537 Solar and stellar variability
DE: 7538 Solar irradiance
DE: 7549 Ultraviolet emissions
DE: 0342 Middle atmosphere--energy deposition
DE: 0358 Thermosphere--energy deposition
SC: SPA-Aeronomy [SA]
MN: 2004 AGU Fall Meeting