@Article{ClemeshaSimo:1990:CoPaEn,
               author = "Clemesha, Barclay Robert and Simonich, Dale Martin",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Comments on a paper entitled {"}Gravity wave generation of 
                         simultaneous auroral sporadic-E layers and sudden neutral sodium 
                         layers{"} by S. Kirkwood and P.N. Collis",
              journal = "Journal of Atmospheric and Solar-Terrestrial Physics",
                 year = "1990",
               volume = "52",
               number = "1",
                pages = "85--86",
             keywords = "gravity waves, auroral sporadic-E layers, neutral sodium layers.",
             abstract = "KIRKWOOD and COLLIS (1989) have suggested that the sudden sodium 
                         layers (SSLs) which have been observed at high latitudes (von ZAHN 
                         et al., 1987; von ZAHN and HANSEN, 1988; GARDNER et al., 1986) 
                         might be produced by strong downward neutral winds, probably 
                         produced by gravity waves resulting from Joule heating caused by 
                         auroral precipitation. They show that the presence of such a wind 
                         could produce enhanced concentrations of minor atmospheric 
                         constituents provided two conditions were met: (1) the vertical 
                         wind would have to decrease rapidly with decreasing height (in 
                         Kirkwood and Collis's model it was reduced to zero just below the 
                         height at which the layer was to be formed), and (2) the mixing 
                         ratio of the minor constituent would have to increase with height 
                         above this point. The suggestion of Kirkwood and Collis is an 
                         interesting one, especially in view of the fact that the 
                         alternative mechanisms which have been suggested in the literature 
                         (CLEMESHA et al., 1978, 1980; von ZAHN et al., 1987; CLEMESHA et 
                         al., 1988) have not been shown to explain all the observed 
                         characteristics of enhanced sodium layers. Unfortunately, however, 
                         there appear to be two fatal flaws in the proposed mechanism.",
                 issn = "1364-6826",
                label = "7082",
             language = "en",
           targetfile = "1-s2.0-0021916990901187-main.pdf",
        urlaccessdate = "01 maio 2024"
}