@Article{TsurutaniEcheGonz:2011:CoMiSm,
               author = "Tsurutani, B. T. and Echer, Ezequiel and Gonzalez, Walter 
                         Demetrio",
          affiliation = "CALTECH, Jet Prop Lab, Pasadena, CA USA and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "The solar and interplanetary causes of the recent minimum in 
                         geomagnetic activity (MGA23): a combination of midlatitude small 
                         coronal holes, low IMF <I>B</I><sub>Z</sub> variances, low solar 
                         wind speeds and low solar magnetic fields",
              journal = "Annales Geophysicae",
                 year = "2011",
               volume = "29",
               number = "5",
                pages = "839--849",
             keywords = "Magnetospheric physics, Solar wind-magnetosphere interactions, 
                         ORIGIN, STORMS, CYCLE.",
             abstract = "Minima in geomagnetic activity (MGA) at Earth at the ends of SC23 
                         and SC22 have been identified. The two MGAs (called MGA23 and 
                         MGA22, respectively) were present in 2009 and 1997, delayed from 
                         the sunspot number minima in 2008 and 1996 by similar to 1/2-1 
                         years. Part of the solar and interplanetary causes of the MGAs 
                         were exceptionally low solar (and thus low interplanetary) 
                         magnetic fields. Another important factor in MGA23 was the 
                         disappearance of equatorial and low latitude coronal holes and the 
                         appearance of midlatitude coronal holes. The location of the holes 
                         relative to the ecliptic plane led to low solar wind speeds and 
                         low IMF (B(z)) variances (sigma(2)(Bz)) and normalized variances 
                         (sigma(2)(Bz)/B(0)(2)) at Earth, with concomitant reduced solar 
                         wind-magnetospheric energy coupling. One result was the lowest ap 
                         indices in the history of ap recording. The results presented here 
                         are used to comment on the possible solar and interplanetary 
                         causes of the low geomagnetic activity that occurred during the 
                         Maunder Minimum.",
                  doi = "10.5194/angeo-29-839-2011",
                  url = "http://dx.doi.org/10.5194/angeo-29-839-2011",
                 issn = "0992-7689",
                label = "lattes: 3368023405805386 3 TsurutaniEcheGonz:2011:CoMiSm",
             language = "en",
           targetfile = "angeo-29-839-2011.pdf",
        urlaccessdate = "05 maio 2024"
}