Comment on the
paper by Dalin, Pertsev and Romejko "Significance
of lunar impact on noctilucent clouds"
critical review of the paper by Dalin, Pertsev and Romejko "Significance of
lunar impact on noctilucent clouds" , JASTP 2006, is presented.
Noctilucent clouds, Moon influence, Mesosphere
note with interest the study by Dalin, Pertsev and Romejko
(2006) on the influence of Moon
position on the frequency of noctilucent clouds (NLC). The problem is not a new
one, because for many years researchers have sought a relationship between the
Moon and NLC, and more generally mesospheric constitution.
general the observations which have been used by Dalin et. al. are very few
inhomogeneous and not valid statistically. The observers were mostly amateurs
without much experience in atmospheric physics, and it is known that the Russian
data often are questionable. One example is the so-called winter observations of
NLC which has been pointed only by Russian data, never from other long-term
series from other countries (Europe, USA, cf. e.g. Fogle, 1964, Schröder, 1970)
understand the problem in finding periodicity in NLC activity, we should note
following points. The first complete and reliable data was observed between
1885-1898 by Jesse using visual and photographic techniques. These were followed
in Germany by the observations of increased airglow between 1922-1967 by Cuno
Hoffmeister, who also looked for NLC. Between 1898-1956 various sporadic data
are also available from Germany. The most complete series is that from Rönnebeck
since 1957. For USSR and Russia, before 1957 there are no complete data sets.
That used by Dalin et. al. are mostly sporadic observations by very
inexperienced observers. Since 1957 several groups in the USSR have taken
observations, but also for a period of few years with variable quality.
Therefore Dalin's data-set is not very convincing.. In America good data has
been collected by Fogle since 1963
for some years, but not a long series of observations. The Western Europe data,
used e.g. by Gadsden (e.g. Gadsden and Schröder, 1989) is also of variable
quality and contribued by an inhomogenous network of amateurs.
general, we must see that for all research to find periodicities or relationship
in this visual data, that all of these not complete and not in the necessary
case valid. Conclusions from these data are very limited and questionable. It is
dangeorus to seek periodicities in sporadic sets of observations made by
disparate groups of observers.
this background and analysis given by Dalin et. al has no fundamental basis.
Physically the genesis of NLC is dependent on the moisture, the absence of
turbulence, the presence of nucleous particles and the time between the
mesospheric transitions. These are the fundamental requirements for the
generation of NLC. The atmosphere near the mesopause is a dynamical body which
is mainly controlled by the wind and temperature and these are components do not
physically depend on the position of the Moon.Therefore all conclusion of a
Lunar periodicity make no sense physically.
is needed are long-term
observations from the ground, photographs and satellite, but these are not yet
available. Furthermore past
observations have been made from a relatively small part of the Earth.
proper coordinated global watch for NLC using consistent techniques would
certainly be valuable in resolving outstanding problems in this field.
P.A., N.N. Pertsev, V.A. Romejko. 2006 Significance of lunar impact on
noctilucent clouds. Journal atmospheric and
solar-terrestrial physics ,
B.1964. Noctilucent clouds. University Alaska G R 164.
M., and W. Schröder, 1989. Noctilucent clouds. New York: Springer.
W., 1967. Studies on noctilucent clouds during the years 1957-1966.
Gerlands Beitäg zur. Geophysik,
Schröder, W. 1970. On
noctilucent clouds. Zeitschrift für Meteorologie 22. Heft 6