64 citations · 156 across the 5 of their papers we have counts for
5 papers
Photospheric Velocities Measured at Mt. Wilson Show Zonal and Sectoral Flows Compose the Torsional Oscillations
Roger K. Ulrich, Tham Tran, John Boyden
The methods for reducing the observations from the 150-foot Tower Telescope on Mt.~Wilson are reviewed and a new method for determining the North/South (sectoral) and the East/West…
The Mount Wilson Ca II K index
Luca Bertello, Roger K. Ulrich, John E. Boyden
It is well established that both total and spectral solar irradiance are modulated by variable magnetic activity on the solar surface. However, there is still disagreement about th…
Modeling Total Solar Irradiance Variations Using Automated Classification Software On Mount Wilson Data
R. K. Ulrich, D. Parker, L. Bertello +1
We present results using the AutoClass analysis application available at NASA/Ames Intelligent Systems Div. (2002) which is a Bayesian, finite mixture model classification system d…
Search for Short-Term Periodicities in the Sun's Surface Rotation: A Revisit
J. Javaraiah, R. K. Ulrich, L. Bertello +1
The power spectral analyses of the Sun's surface equatorial rotation rate determined from the Mt. Wilson daily Doppler velocity measurements during the period 3 December 1985 to 5…
Interpretation of Solar Magnetic Field Strength Observations
R. K. Ulrich, L. Bertello, J. E. Boyden +1
This study based on longitudinal Zeeman effect magnetograms and spectral line scans investigates the dependence of solar surface magnetic fields on the spectral line used and the w…