author = "Franz, M. and Echer, Ezequiel and Souza, Adriane Marques de and 
                         Dubinin, E. and Zhang, T. L.",
          affiliation = "{Max-Planck-Institut f{\"u}r Sonnensystemforschung} and 
                         {Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Max-Planck-Institut 
                         f{\"u}r Sonnensystemforschung} and {Space Research Institute of 
                         the Austrian Academy of Sciences}",
                title = "Ultra low frequency waves at Venus: observations by the venus 
                         express spacecraft",
              journal = "Planetary and Space Science",
                 year = "2017",
               volume = "146",
                pages = "55--65",
                month = "Oct.",
             keywords = "Solar wind-Venus interactionPlanetary magnetosheathsPlasma 
                         wavesInduced magnetospheres.",
             abstract = "The generation of waves with low frequencies (below 100 mHz) has 
                         been observed in the environment of most bodies in the solar 
                         system and well studied at Earth. These waves can be generated 
                         either upstream of the body in the solar wind by ionization of 
                         planetary exospheres or ions reflected from a bow shock or in the 
                         magnetosheath closer to the magnetic barrier. For Mars and Venus 
                         the waves may have special importance since they can contribute to 
                         the erosion of the ionopause and by that enhance atmospheric 
                         escape. While over the past years many case studies on wave 
                         phenomena observed at Venus have been published most statistical 
                         studies have been based on magnetic observations only. On the 
                         other hand the generation mechanisms and transport of these waves 
                         through the magnetosphere can only be quantified using both 
                         magnetic and particle observations. We use the long time 
                         observations of Venus Express (20062014) to determine the 
                         predominant processes and transport parameters. First we 
                         demonstrate the analysis methods in four case studies, then we 
                         present a statistical analysis by determining transport ratios 
                         from the complete Venus Express dataset. We find that Alfvenic 
                         waves are very dominant (>80%) in the solar wind and in the core 
                         magnetosheath. Fast waves are observed mainly at the bow shock 
                         (around 40%) but also at the magnetic barrier where they may be 
                         most important for the energy transfer into the ionosphere. Their 
                         occurrence in the magnetotail may be an artifact of the detection 
                         of individual plasma jets in this region. Slow mode waves are 
                         rarely dominating but occur with probability of about 10% at the 
                         bow shock and in the pile-up-region. Mirror mode waves have 
                         probability <20% in the magnetosheath slightly increasing towards 
                         the pile-up-boundary.",
                  doi = "10.1016/j.pss.2017.08.011",
                  url = "http://dx.doi.org/10.1016/j.pss.2017.08.011",
                 issn = "0032-0633",
             language = "en",
           targetfile = "franz_ultra.pdf",
        urlaccessdate = "17 jan. 2021"