E-Print Archive

There are 3923 abstracts currently viewable.


Search:

Advanced Search
Options
Main Page Add New E-Print Submitter
Information
Feedback
News Help/FAQ About Preferences
Manage Key Phrase
Notification
An alternative measure of solar activity from detailed sunspot datasets  

Judit Muraközy   Submitted: 2016-07-28 07:29

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.

Authors: Muraközy, J., Baranyi, T., Ludmány, A.
Projects: None

Publication Status: accepted for publication in Solar Physics
Last Modified: 2016-07-28 07:56
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 

Phase Relationships of Solar Hemispheric Toroidal and Poloidal Cycles  

Judit Muraközy   Submitted: 2016-07-28 07:26

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 Spürer's data in cycle 11. The previously found variation can not be clearly recognized using the data of Staudacher, Schwabe and Spürer. 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.

Authors: Muraközy, J.
Projects: None

Publication Status: 2016, The Astrophysical Journal, 826 (2), 145, 8pp
Last Modified: 2016-07-28 07:56
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 

An alternative measure of solar activity from detailed sunspot datasets  

Judit Muraközy   Submitted: 2016-03-21 01:03

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.

Authors: Muraközy, J.; Baranyi, T.; Ludmány, A.
Projects: None

Publication Status: Solar Physics (accepted)
Last Modified: 2016-03-21 15:33
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 

Cycle dependence of the longitudinal-latitudinal sunspot motion correlations  

Judit Muraközy   Submitted: 2013-09-10 03:23

Aims: It is well known that the azimuthal and meridional shifts ofsunspots are correlated and that the correlation exhibits alatitudinal distribution, which is expected due to the Corioliseffect. We study the temporal behaviour of this latitudinaldistribution.
Methods: We analyze the daily positions of sunspotgroups, provided by the Debrecen Photoheliographic Data and theGreenwich Photoheliographic Results and correlation values, which weremapped in 5° latitudinal bins. The latitudinal distributions wereexamined for each year.
Results: We derive a sunspot-motioncorrelation that exhibits a Coriolis-type latitudinal distribution onlong timescales, which are typical for the yearly distributions; atcycle maximum, however, unexpected distortions can occur.
Conclusions:The causes of the weakening of the Coriolis-pattern remain unclear.Possible relations of the phenomenon to the Gnevyshev-gap, thepolarity reversal of the main magnetic field, and some mid-periodfluctuations are discussed.

Authors: J. Muraközy, A. Ludmány
Projects:

Publication Status: A&A (published)
Last Modified: 2013-09-11 07:21
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 

Sunspot Group Development in High Resolution  

Judit Muraközy   Submitted: 2013-09-10 03:20

The Solar and Heliospheric Obseratory/Michelson Doppler Imager-Debrecen Data (SDD) sunspot catalogue provides an opportunity to study the details and development of sunspot groups on a large statistical sample. The SDD data allow, in particular, the differential study of the leading and following parts with a temporal resolution of 1.5 hours. In this study, we analyse the equilibrium distance of sunspot groups as well as the evolution of this distance over the lifetime of the groups and the shifts in longitude associated with these groups. We also study the asymmetry between the compactness of the leading and following parts, as well as the time-profiles for the development of the area of sunspot groups. A logarithmic relationship has been found between the total area and the distance of leading-following parts of active regions (ARs) at the time of their maximum area. In the developing phase the leading part moves forward; this is more noticeable in larger ARs. The leading part has a higher growth rate than the trailing part in most cases in the developing phase. The growth rates of the sunspot groups depend linearly on their maximum total umbral area. There is an asymmetry in compactness: the number of spots tends to be smaller, while their mean area is larger in the leading part at the maximum phase.

Authors: J. Muraközy, T. Baranyi, A. Ludmány
Projects:

Publication Status: accepted in Solar Physics
Last Modified: 2013-09-11 07:21
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 

Phase lags of solar hemispheric cycles  

Judit Muraközy   Submitted: 2013-09-10 03:14

The North-South asymmetry of solar activity is variable in time and strength. We analyse the long-term variation of the phase lags of hemispheric cycles and check a conjectured relationship between these phase lags and the hemispheric cycle strengths. Sunspot data are used from cycles 12-23 in which the separation of northern and southern hemispheres is possible. The centers of mass of the hemispheric cycle profiles were used to study the phase relations and relative strengths of the hemispheric cycles. This approach considers a cycle as a whole and disregards the short-term fluctuations of the cycle time profile. The phase of the hemispheric cycles shows an alternating variation: the northern cycle leads in 4 cycles and follows in 4 cycles. No significant relationship is found between the phase and strength differences of the hemispheric cycles. The period of 4+4 cycles appears to be close to the Gleissberg cycle and may provide a key to its physical background. It may raise a new aspect in the solar dynamo mechanism because it needs a very long memory.

Authors: J. Muraközy, A. Ludmány
Projects: None

Publication Status: published in MNRAS
Last Modified: 2013-09-10 13:20
Go to main E-Print page  Edit Entry  Download Preprint  Delete Entry 


Key
Go to main E-Print pageGo to main E-Print page.
Download PreprintDownload Preprint.
Submitter's HomepageSubmitters Homepage.
Edit EntryEdit Entry.
Delete AbstractDelete abstract.

Abstracts by Author
An alternative measure of solar activity from detailed sunspot datasets
Phase Relationships of Solar Hemispheric Toroidal and Poloidal Cycles
An alternative measure of solar activity from detailed sunspot datasets
Cycle dependence of the longitudinal-latitudinal sunspot motion correlations
Sunspot Group Development in High Resolution
Phase lags of solar hemispheric cycles

Related Pages
MSU Solar Physics.
Max Millennium Science Mail Archive.
Max Millennium Message of the Day Mail Archive.
Max Millennium Flare Catalog

Archive Maintainer
Alisdair Davey



© 2003 Solar Physics Group - Montana State University