@Article{Kane:2008:LaDeVa,
               author = "Kane, Rajaram Purushotam",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Latitude Dependence of the Variations of Sunspot Group Numbers 
                         (SGN) and Coronal Mass Ejections (CMEs) in Cycle 23",
              journal = "Solar Physics",
                 year = "2008",
               volume = "249",
               number = "2",
                pages = "355--367",
                month = "June",
             abstract = "The 12-month running means of the conventional sunspot number Rz, 
                         the sunspot group numbers (SGN) and the frequency of occurrence of 
                         Coronal Mass Ejections (CMEs) were examined for cycle 23 
                         (1996\ \ 2006). For the whole disc, the SGN and Rz 
                         plots were almost identical. Hence, SGN could be used as a proxy 
                         for Rz, for which latitude data are not available. SGN values were 
                         used for 5° latitude belts 0°\ \ 5°, 
                         5°\ \ 10°, 10°\ \ 15°, 
                         15°\ \ 20°, 20°\ \ 25°, 
                         25°\ \ 30° and >\ 30°, separately in each 
                         hemisphere north and south. Roughly, from latitudes 
                         25°\ \ 30° N to 20°\ \ 25° N, the 
                         peaks seem to have occurred later for lower latitudes, from 
                         latitudes 20°\ \ 25° N to 15°\ \ 20° 
                         N, the peaks are stagnant or occur slightly earlier, and then from 
                         latitudes 15°\ \ 20° N to 0°\ \ 5° N, 
                         the peaks seem to have occurred again later for lower latitudes. 
                         Thus, some latitudinal migration is suggested, clearly in the 
                         northern hemisphere, not very clearly in the southern hemisphere, 
                         first to the equator in 1998, stagnant or slightly poleward in 
                         1999, and then to the equator again from 2000 onwards, the latter 
                         reminiscent of the Maunder butterfly diagrams. Similar plots for 
                         CME occurrence frequency also showed multiple peaks (two or three) 
                         in almost all latitude belts, but the peaks were almost 
                         simultaneous at all latitudes, indicating no latitudinal 
                         migration. For similar latitude belts, SGN and CME plots were 
                         dissimilar in almost all latitude belts except 
                         10°\ \ 20° S. The CME plots had in general more 
                         peaks than the SGN plots, and the peaks of SGN often did not match 
                         with those of CME. In the CME data, it was noticed that whereas 
                         the values declined from 2002 to 2003, there was no further 
                         decline during 2003\ \ 2006 as one would have 
                         expected to occur during the declining phase of sunspots, where 
                         2007 is almost a year of sunspot minimum. An inquiry at GSFC-NASA 
                         revealed that the person who creates the preliminary list was 
                         changed in 2004 and the new person picks out more weak CMEs. Thus 
                         a subjectivity (overestimates after 2002) seems to be involved and 
                         hence, values obtained before and during 2002 are not directly 
                         comparable to values recorded after 2002, except for CMEs with 
                         widths exceeding 60°.",
                  doi = "10.1007/s11207-008-9184-x",
                  url = "http://dx.doi.org/10.1007/s11207-008-9184-x",
                 issn = "0038-0938 and 1573-093X",
             language = "en",
           targetfile = "latitude dependence.pdf",
        urlaccessdate = "05 maio 2024"
}