RESULTS OF MONITORING FIELDS OF NLC IN SEASONS 2017 - 2018

Abstract

In order to develop new effective methods for recording fields of silvery clouds, the
results of panoramic monitoring of the twilight segment conducted in the summer seasons of 2017-
2018 were analyzed. The observations used a wide-angle monochrome camera Arecont
AV40185DN-HB, which has a field of view up to 180 degrees azimuth. It is shown that the use of this camera allows not only to successfully record the appearance of silvery clouds, but also to
study their structure and kinematics by subsequent image analysis. In particular, it was found that
the change in the total azimuthal extent of cloud fields during the night was determined mainly by
the influence of changes in the conditions of their illumination by the Sun. Panoramic monitoring
also allowed to detect rare events associated with the emergence and rapid development of peculiar
elements of the cloud field. In particular, the fact of the appearance of a separate fiber-like detail of
the cloud field on the night of 3 to 4 July 2018, the appearance and development of which was asso-
ciated with the evolution of the cold tropospheric front over the territory of the West Siberian low-
land, is considered. It is concluded that the use of panoramic monitoring of the twilight segment is
promising not only to improve SYNOPTIC observations of silvery clouds, but also to clarify the
conclusions about the nature of tropospheric-mesospheric connections.