33 citations · 100 across the 5 of their papers we have counts for
5 papers
A Curious History of Sunspot Penumbrae: An Update
V. M. S. Carrasco, J. M. Vaquero, R. M. Trigo +1
The ratio of penumbral to umbral area of sunspots is an important topic for solar and geophysical studies. Hathaway (Solar Physics, 286, 347, 2013) found a curious behaviour in thi…
Revised Group Sunspot Number for 1640, 1652, and 1741
J. M. Vaquero, R. M. Trigo
Some studies have shown that our knowledge on solar activity in the years 1640, 1652, and 1741 can be improved. In this contribution, we revise the annual group sunspot numbers for…
A Note on Solar Cycle Length during the Medieval Climate Anomaly
J. M. Vaquero, R. M. Trigo
The growing interest in the "Medieval Climate Anomaly" (MCA) and its possible link to anomalous solar activity has prompted new reconstructions of solar activity based on cosmogeni…
A Simple Method to Check the Reliability of Annual Sunspot Number in the Historical Period 1610-1847
J. M. Vaquero, R. M. Trigo, M. C. Gallego
A simple method to detect inconsistencies in low annual sunspot numbers based on the relationship between these values and the annual number of active days is described. The analys…
155-day Periodicity in Solar Cycles 3 and 4
J. M. Vaquero, R. M. Trigo, M. Vazquez +1
The near 155 days solar periodicity, so called Rieger periodicity, was first detected in solar flares data and later confirmed with other important solar indices. Unfortunately, a…