Synoptic Studies of Solar Magnetism and Dynamics Using the 150-foot Solar Tower on Mt. Wilson

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The investigators will conduct research primarily to enhance understanding of solar variability. The main effort is to continue, and indeed to improve, the synoptic program of observations at the 150-foot solar tower on Mt. Wilson that measures and records the state of solar surface magnetism and dynamics. The sun is the dominant source of external variability for the Earth's climate system and is the source of space weather. Direct study of the sun is an essential part of a program to understand climate change and to monitor and predict the state of space weather. This project emphasizes solar magnetism because most solar variability is directly influenced by the state of the sun's magnetic field. The cause or causes of the twenty-two-year solar magnetic cycle remain an elusive problem that prevents addressing variability in a fully satisfactory manner. Since the magnetic cycle is of a fully global scale on the solar surface, data on all timescales are essential to discover the underlying causes of solar variability. Each day the Mt. Wilson Observatory (MWO) program obtains up to twenty full disk scans of the sun's magnetic field and velocity field to provide a record which can address questions of global solar variability. The historical time series of both fields must be sufficiently long to study the solar cycle and the 150-foot tower program has provided this history since its digital record began in 1967. As part of this project the investigators will consider several corrections to the older data and will organize a workshop for the intercomparison of the magnetic field data among investigators who now regularly obtain full-disk magnetogram and dopplergram records.