Modeling Solar UV/EUV Irradiance and Ionosphere Variations with Mt. Wilson Magnetic Indicies
Abstract
The long term goal for this project is to develop, extend and disseminate new indicies of solar outputs based on observations of solar magnetic fields made every clear day at the Mt. Wilson Observatory's 150-foot solar tower. The data reduction is done within hours of at least one observation per day (weather permitting) and the results of the reduction are made available through the worldwide web. The analysis of the past database together with timely dissemination of new data is for the purpose of improving forecasts of the state of the earth's ionosphere in order to better predict the communications environment which relies on radio reflections from the various layers of the upper atmosphere. The emissivity of the solar atmosphere depends on the strength of the magnetic field on the sun's surface. The solar surface is highly inhomogeneous and contains at least four types of region: quiet sun, chromospheric network, plages and sunspots. Each type of region contributes differently to the total flux of UV, EUV and X-ray output. The solar surface magnetic field is a recognized indicator of the nature and strength of each type of solar region. Our plan is to use the magnetograms obtained at the 150-foot tower on Mt. Wilson to quantitatively divide the solar surface into the different classifications and assign a strength of emission on the basis of the observed magnetic field strength. Previous analysis has shown that the plage regions can be well identified from the magnetic field.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1998
- Accession Number
- ADA572532
Entities
People
- Roger K. Ulrich
Organizations
- University of California, Los Angeles