69 citations · 245 across the 10 of their papers we have counts for
11 papers
A new solar signal: Average maximum sunspot magnetic fields independent of activity cycle
William Livingston, Fraser Watson
Over the past five years, 2010-2015, we have observed, in the near infrared (IR), the maximum magnetic field strengths for 4145 sunspot umbrae. Herein we distinguish field strength…
Cross-Calibrating Sunspot Magnetic Field Strength Measurements from the McMath-Pierce Solar Telescope and the Dunn Solar Telescope
Fraser T. Watson, Christian Beck, Matthew J. Penn +3
In this article we describe a recent effort to cross-calibrate data from an infrared detector at the McMath-Pierce Solar Telescope and the Facility InfraRed Spectropolarimeter (FIR…
A Multi-Instrument Analysis of Sunspot Umbrae
Fraser T. Watson, Matthew J. Penn, William C. Livingston
The recent solar minimum and rise phase of solar cycle 24 have been unlike any period since the early 1900s. This article examines some of the properties of sunspot umbrae over the…
Image patch analysis of sunspots and active regions. II. Clustering via matrix factorization
Kevin R. Moon, Veronique Delouille, Jimmy J. Li +3
Separating active regions that are quiet from potentially eruptive ones is a key issue in Space Weather applications. Traditional classification schemes such as Mount Wilson and Mc…
Image patch analysis of sunspots and active regions. I. Intrinsic dimension and correlation analysis
Kevin R. Moon, Jimmy J. Li, Veronique Delouille +3
The flare-productivity of an active region is observed to be related to its spatial complexity. Mount Wilson or McIntosh sunspot classifications measure such complexity but in a ca…
Small-Scale and Global Dynamos and the Area and Flux Distributions of Active Regions, Sunspot Groups, and Sunspots: A Multi-Database Study
Andrés Muñoz-Jaramillo, Ryan R. Senkpeil, John C. Windmueller +12
In this work we take advantage of eleven different sunspot group, sunspot, and active region databases to characterize the area and flux distributions of photospheric magnetic stru…
Image patch analysis and clustering of sunspots: a dimensionality reduction approach
Kevin R. Moon, Jimmy J. Li, Veronique Delouille +2
Sunspots, as seen in white light or continuum images, are associated with regions of high magnetic activity on the Sun, visible on magnetogram images. Their complexity is correlate…
A Multi-Wavelength Analysis of Active Regions and Sunspots by Comparison of Automated Detection Algorithms
Cis Verbeeck, Paul A. Higgins, Tufan Colak +4
Since the Solar Dynamics Observatory (SDO) began recording ~ 1 TB of data per day, there has been an increased need to automatically extract features and events for further analysi…
Evolution of sunspot properties during solar cycle 23
Fraser T. Watson, Lyndsay Fletcher, Stephen Marshall
The long term study of the Sun is necessary if we are to determine the evolution of sunspot properties and thereby inform modeling of the solar dynamo, particularly on scales of a…
Automated sunspot detection and the evolution of sunspot magnetic fields during solar cycle 23
Fraser Watson, Lyndsay Fletcher
The automated detection of solar features is a technique which is relatively underused but if we are to keep up with the flow of data from spacecraft such as the recently launched…
Modeling the Longitudinal Asymmetry in Sunspot Emergence -- the Role of the Wilson Depression
Fraser Watson, Lyndsay Fletcher, Silvia Dalla +1
The distributions of sunspot longitude at first appearance and at disappearance display an east-west asymmetry that results from a reduction in visibility as one moves from disk ce…