An alternative measure of solar activity from detailed sunspot datasets

The sunspot number is analyzed by using detailed sunspot data, including aspects of observability, sunspot sizes, and proper identification of sunspot groups as discrete entities of the solar activity. The tests show that besides the subjective factors there are also objective causes of the ambiguities in the series of sunspot numbers. To introduce an alternative activity measure the physical meaning of the sunspot number has to be reconsidered. It contains two components whose numbers are governed by different physical mechanisms, this is one source of the ambiguity. This article suggests an activity index, which is the amount of emerged magnetic flux. The only long-term proxy measure is the detailed sunspot area dataset with proper calibration to the magnetic flux amount. The Debrecen sunspot databases provide an appropriate source for the establishment of the suggested activity index.Comment: 11 pages, 8 figure

Variations of the Internal Asymmetries of Sunspot Groups during Their Decay

The aim of the present study is to show the varying asymmetries during the decay of sunspot groups. The source of input data is the SoHO/MDI-Debrecen Database (SDD) sunspot catalog that contains the magnetic polarity data for time interval 1996-2010. Several types of asymmetries were examined on the selected sample of 142 sunspot groups. The leading-following asymmetry increases in three phases during the decay and exhibits anticorrelation with size. It is also related to a hemispheric asymmetry, during the decay the area asymmetry index has higher values in the southern hemisphere which may be due to the higher activity level in the southern hemisphere in cycle 23. The total umbral area is inversely proportional to the umbra/penumbra ratio but it is directly proportional to the umbral decay rate. During the decay the umbra/penumbra (U/P) ratio decreases unambiguously in the trailing parts but in most cases in the leading parts as well. The U/P variation is a consequence of the different depths of umbral and penumbral fields.Comment: accepted for publication in the ApJ, 9 pages, 6 figure

Phase Relationships of Solar Hemispheric Toroidal and Poloidal Cycles

The solar northern and southern hemispheres exhibit differences between the intensities and time profiles of the activity cycles. The time variation of these properties has been studied in a previous article on the data of Cycles 12-23. The hemispheric phase lags exhibited a characteristic variation: the leading role has been exchanged between the hemispheres by four cycles. The present work extends the investigation of this variation with the data of Schwabe and Staudacher in Cycles 1-4 and 7-10 as well as Sp\"orer's data in cycle 11. The previously found variation can not be clearly recognized using the data of Staudacher, Schwabe and Sp\"orer. However, it is more interesting that the phase lags of the reversals of the magnetic fields at the poles follow the same variation as that of the hemispheric cycles in Cycles 12-23, i.e. in four cyles one of the hemispheres leads and the leading role jumps to the opposite hemisphere in the next four cycles. This means that this variation is a long term property of the entire solar dynamo mechanism, both the toroidal and poloidal fields, that hints at an unidentified component of the process responsible for the long term memory.Comment: 25 pages, 11 figure