53 citations · 184 across the 6 of their papers we have counts for
6 papers
The global solar magnetic field -- identification of travelling, long-lived ripples
Roger K. Ulrich, Tham Tran
We have examined the global structure of the solar magnetic field using data from the FeI spectral line at λ5250.2Å obtained at the 150-foot tower telescope at the Mt. Wilson Obser…
Astrometric jitter of the sun as a star
V. V. Makarov, D. Parker, R. K. Ulrich
The daily variation of the solar photocenter over some 11 years is derived from the Mount Wilson data reprocessed by Ulrich et al. 2010 to closely match the surface distribution of…
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…
Random Lag Singular Cross-Spectrum Analysis
F. Varadi, R. K. Ulrich, L. Bertello +1
In a previous paper (Varadi et al., 1999), Random Lag Singular Spectrum Analysis was offered as a tool to find oscillations in very noisy and long time series. This work presents a…