%0 Journal Article
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@nexthigherunit 8JMKD3MGPCW/3ETL868
%@archivingpolicy denypublisher denyfinaldraft24
%3 1-s2.0-0021916990901187-main.pdf
%X 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.
%N 1
%@secondarydate 19960311
%T 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
%@electronicmailaddress brc@laser.inpe.br
%@electronicmailaddress simonich@laser.inpe.br
%K gravity waves, auroral sporadic-E layers, neutral sodium layers.
%@secondarytype PRE PI
%@usergroup administrator
%@usergroup banon
%@usergroup jefferson
%@group DAE-INPE-BR
%@group DAE-INPE-BR
%@secondarykey INPE-5687-PRE/1844
%F 7082
%@issn 1364-6826
%2 sid.inpe.br/iris@1905/2005/07.29.00.34
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@project FNDCT (FINEP 537/CT).
%B Journal of Atmospheric and Solar-Terrestrial Physics
%@versiontype publisher
%P 85-86
%4 sid.inpe.br/iris@1905/2005/07.29.00.33.59
%@documentstage not transferred
%D 1990
%V 52
%A Clemesha, Barclay Robert,
%A Simonich, Dale Martin,
%@dissemination WEBSCI; PORTALCAPES; COMPENDEX.
%@area CEA