8 research outputs found
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 Solar Non-axisymmetric Activity
The temporal behaviour of solar active longitudes has been examined by using two sunspot catalogues, the Greenwich Photoheliographic Results (GPR) and the Debrecen Photoheliographic Data (DPD). The time-longitude diagrams of the activity distribution reveal the preferred longitudinal zones and their migration with respect to the Carrington frame. The migration paths outline a set of patterns in which the activity zone has alternating prograde/retrograde angular velocities with respect to the Carrington rotation rate. The time profiles of these variations can be described by a set of successive parabolae. Two similar migration paths have been selected from these datasets, one northern path during cycles 21 - 22 and one southern path during cycles 13 - 14, for closer examination and comparison of their dynamical behaviours. The rates of sunspot emergence exhibited in both migration paths similar periodicities, close to 1.3 years. This behaviour may imply that the active longitude is connected to the bottom of convection zone
GeoeffektĂv szoláris Ă©s interplanetáris jelensĂ©gek vizsgálata = Study of geoeffective solar and interplanetary phenomena
FĹ‘ cĂ©lunk az volt, hogy elĹ‘relĂ©pĂ©s törtĂ©njen a Debrecen Photoheliographic Data (DPD) napfolt-adatbázis kĂ©szĂtĂ©sĂ©ben, mely többek között a szoláris irradianciaváltozások modellezĂ©sĂ©hez szĂĽksĂ©ges. A beszámolási idĹ‘szak alatt 6 Ă©v anyaga kĂ©szĂĽlt el Ă©s mára az 1986-1990 Ă©s 1993-98 közötti idĹ‘szak adatai már használhatĂłk kutatásra, a jelenleg mĂ©rĂ©s alatt lĂ©vĹ‘kkel egyĂĽtt pedig az 1982-2003 Ă©vekre terjed ki a munka. Több cikkĂĽnk foglalkozik a DPD mĂłdszertani fejlesztĂ©sĂ©vel Ă©s prezentáciĂłjával. Az irradianciamodellezĂ©s megbĂzhazĂłságának növelĂ©sĂ©hez nĂ©lkĂĽlözhetetlen összehasonlĂtĂł vizsgálatokat vĂ©geztĂĽnk a kĂĽlönbözĹ‘ napfolt-adatbázisokkal. Az irradianciát egy további munkánk Ă©rinti, a MnI 539,47nm vonal viselkedĂ©sĂ©t Ărtuk le, mely ĂgĂ©retes irradiancia-indikátor. EzenfelĂĽl vizsgáltunk a DPD alapján a foltterĂĽletek kelet-nyugati aszimmetriáját, Ă©s a folteloszlások kapcsolatát a torziĂłs hullámmal. CĂ©lkitűzĂ©seink második csoportját a plazmaáramok rĂ©vĂ©n közvetĂtett Nap-Föld hatások vizsgálata jelentette. Megmutattuk, hogyan fĂĽgg a plazmák mágneses komponenseinek Ă©s sebessĂ©gĂ©nek fĂ©lĂ©ves viselkedĂ©se a szoláris mágneses dipĂłltĂ©r polaritásátĂłl, valamint leĂrtunk egy Ă©szak-dĂ©li illetve egy kelet-nyugati aszimmetriát a szoláris plazmák Ă©s a magnetoszfĂ©ra kölcsönhatásaiban. Megadtunk egy lehetsĂ©ges sĂ©mát a szoláris Ă©s alsĂłlĂ©gköri jelensĂ©gek között vĂ©gbemenĹ‘ hatásmechanizmusra. Harmadik cĂ©lunk a napkitörĂ©sek idĹ‘beli viselkedĂ©sĂ©nek vizsgálata volt, leĂrtuk egy fler kváziperiodikus fluktuáciĂłját. | The main task was an advancement in the edition of the Debrecen Photoheliographic Data (DPD) which is a sunspot database necessary, among others, for irradiance variation models. The materials of 6 years have been completed during the project, now the data of the 1986-1990 and 1993-1998 are available for investigations and the work extends to the years 1982-2003 with the periods under measurements. Several papers are devoted to the methodology of DPD and its presentation. We compared different sunspot databases which is needed to the improvement of the irradiance models. The irradiance is referred to in another work: the behaviour of the MnI 539,47nm line (a promising irradiance indicator) was described. In addition two other phenomena have been studied on the basis of the DPD: the East-West asymmetry of spot areas and the connection of spot distributions with the torsional wave. The next group of our aims was the study of Sun-Earth impacts transferred by plasma streams. We analysed the dependence of the semiannual behaviour of plasma velocity and magnetic components on the polarity of the solar magnetic dipole field, furthermore we described asymmetries of North-South as well as of East-West type in the interaction of the solar plasmas and the magnetosphere. We provided a possible scheme for the chain of impacts between the solar and troposhperic phenomena. The third aim was the temporal analysis of flare events. We described the quasiperiodic fluctuation of a flare