HR: 1330h
AN: SH32A-1099    [PDF]
TI: Magnetic Field and Long-Term Solar Irradiance Variations Over Solar Cycles 21 to 23
AU: * Pap, J M
EM: papj@marta.gsfc.nasa.gsfc
AF: University of Maryland Baltimore County, NASA/Goddard Space Flight Center, Code 680.0, Greenbelt, MD 20771 United States
AU: Turmon, M
EM: turmon@aig.jpl.nasa.gov
AF: Jet Propuslion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Shelton, K E
EM: kacie@aig.jpl.nasa.gov
AF: Jet Propuslion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AU: Floyd, L E
EM: linton.floyd@nrl.navy.mil
AF: Interferometric Inc., Naval Research Laboratory, Code 7660, Washington, DC 20375 United States
AU: Helizon, R
EM: roger@simdac.jpl.nasa.gov
AF: Jet Propuslion Laboratory, 4800 Oak Grove Dr., Pasadena, CA 91109 United States
AB: Total solar and UV irradiance has been measured from various space platforms over the last two and half solar cycles. Results based on these multi-decade measurements have demonstrated that both total and UV irradiances change on time scales of days to decades, confirming that our Sun is indeed a variable star. High spatial and temporal resolution photometric and magnetic field observations conducted by the SOHO/MDI experiment and also from the ground have demonstrated that the surface of the Sun and its outer atmosphere are highly variable on almost all spatial scales. To understand the physical causes of irradiance variations, it is necessary to study the spatial and temporal characteristics and evolution of the solar magnetic fields and to establish to what extent solar magnetic features may contribute to irradiance variations. In this paper we analyze the total solar and UV irradiance composites compiled from various space measurements starting in late 1978. To establish the effect of surface magnetic activity on irradiance variations as a function of the solar cycle, we show the association of the absolute value of the full disk magnetic field strength data measured and compiled at the National Solar Observatory at Kitt Peak for the time interval of 1978 to date. Using various pattern recognition techniques, we compare the observed irradiance variations with solar features (sunspots and faculae), derived from the MDI and Kitt Peak magnetograms from 1996 and 1992, respectively.
DE: 1650 Solar variability
DE: 7524 Magnetic fields
DE: 7536 Solar activity cycle (2162)
DE: 7538 Solar irradiance
SC: SPA - Solar and Heliospheric Physics [SH]
MN: 2003 Fall Meeting