author = "Selhorst, Caius L. and Kallunki, Juha and Castro, Carlos Guillermo 
                         Gim{\'e}nez de and Valio, Adriana and Costa, Joaquim Eduardo 
          affiliation = "{Universidade Cruzeiro do Sul} and {Mets{\"a}hovi Radio 
                         Observatory} and {Universidade Presbiteriana Mackenzie} and 
                         {Universidade Presbiteriana Mackenzie} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "The solar radius at 37 GHz through cycles 22 to 24",
              journal = "Solar Physics",
                 year = "2019",
               volume = "294",
               number = "12",
                pages = "e175",
                month = "Nov.",
             keywords = "Sun: radio radiation  Solar cycle  Sun: radius.",
             abstract = "To better understand the influence of the activity cycle on the 
                         solar atmosphere, we report the time variation of the radius 
                         observed at 37 GHz (\λ = 8.1 mm) obtained by the 
                         Mets{\"a}hovi Radio Observatory (MRO) through Solar Cycles 22 to 
                         24 (1989 2015). Almost 5800 maps were analyzed, however, due to 
                         instrumental setup changes the dataset showed four distinct 
                         behaviors, which required a normalization process to allow for the 
                         whole interval analysis. When the whole period was considered, the 
                         results showed a positive correlation index of 0.17 between the 
                         monthly means of the solar radius at 37 GHz and solar flux 
                         obtained at 10.7 cm (F10.7). This correlation index increased to 
                         0.44, when only the data obtained during the last period without 
                         instrumental changes were considered (1999 2015). The solar radius 
                         correlation with the solar cycle agrees with the previous results 
                         obtained at mm/cm wavelengths (17 and 48 GHz), nevertheless, this 
                         result is the opposite of that reported at submillimeter 
                         wavelengths (212 and 405 GHz).",
                  doi = "10.1007/s11207-019-1568-6",
                  url = "http://dx.doi.org/10.1007/s11207-019-1568-6",
                 issn = "0038-0938 and 1573-093X",
             language = "en",
           targetfile = "selhorst_solar.pdf",
        urlaccessdate = "17 abr. 2021"