@Article{LiuPlaCleWanChe:2014:MeTrCh,
               author = "Liu, Y. J. and Plane, J. M. C. and Clemesha, Barclay Robert and 
                         Wang, J. H. and Cheng, X. W.",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {University 
                         of Leeds} and {Instituto Nacional de Pesquisas Espaciais (INPE)} 
                         and Center for Space Science and Applied Research, Chinese Academy 
                         of Sciences and Wuhan Institute of Physics and Mathematics, 
                         Chinese Academy of Sciences",
                title = "Meteor trail characteristics observed by high time resolution 
                         lidar",
              journal = "Annales Geophysicae",
                 year = "2014",
               volume = "32",
               number = "10",
                pages = "1321--1332",
             keywords = "atmospheric chemistry, atmospheric structure, lidar, meteor, 
                         modeling, China.",
             abstract = "We report and analyse the characteristics of 1382 meteor trails 
                         based on a sodium data set of <680 h. The observations were made 
                         at Yanqing (115.97° E, 40.47° N), China by a ground-based Na 
                         fluorescence lidar. The temporal resolution of the raw profiles is 
                         1.5 s and the altitude resolution is 96 m. We discover some 
                         characteristics of meteor trails different from those presented in 
                         previous reports. The occurrence heights of the trails follow a 
                         double-peak distribution with the peaks at <83.5 km and at <95.5 
                         km, away from the peak height of the regular Na layer. 4.7% of the 
                         trails occur below 80 km, and 3.25% above 100 km. 75% of the 
                         trails are observed in only one 1.5 s profile, suggesting that the 
                         dwell time in the laser beam is not greater than 1.5 s. The peak 
                         density of the trails as a function of height is similar to that 
                         of the background sodium layer. The raw occurrence height 
                         distribution is corrected taking account of three factors which 
                         affect the relative lifetime of a trail as a function of height: 
                         the meteoroid velocity (which controls the ratio of Na / Na+ 
                         ablated); diffusional spreading of the trail; and chemical removal 
                         of Na. As a result, the bi-modal distribution is more pronounced. 
                         Modelling results show that the higher peak corresponds to a 
                         meteoroid population with speeds between 20 and 30 km s?1, whereas 
                         the lower peak should arise from much slower particles in a 
                         near-prograde orbit. It is inferred that most meteoroids in this 
                         data set have masses of <1 mg, in order for ablation to produce 
                         sufficient Na atoms to be detected by lidar. Finally, the 
                         evolution of longer-duration meteor trails is investigated. 
                         Signals at each altitude channel consist of density enhancement 
                         bursts with the growth process usually faster than the decay 
                         process, and there exists a progressive phase shift among these 
                         altitude channels.",
                  doi = "10.5194/angeo-32-1321-2014",
                  url = "http://dx.doi.org/10.5194/angeo-32-1321-2014",
                 issn = "0992-7689",
                label = "scopus 2014-11 LiuPlaCleWanChe:2014:MeTrCh",
             language = "en",
           targetfile = "Liu_Meteor.pdf",
        urlaccessdate = "05 maio 2024"
}