Dr Peter Dalin (IRF-K)Date:
2004-12-02 00:00Place: Part I. Case study of the role of neutral air turbulence in the PMSE variations. Part II. Concept and technique for the processing of NLC digital photographs.
Part I. There are a lot of theoretical works showing that the neutral air turbulence can play a significant role in the creation of the polar mesosphere summer echoes (PMSE). At the same time the experimental works showed that the turbulence intensities are much too low to produce large radar scatters. On the other hand, some experiments revealed the cases that the regions of maximum radar backscatter correspond to the most unstable phase of gravity wave where the strong turbulence generation takes place. We have found several interesting cases supported the latter phenomenon. The regions of gravity wave propagations and strong wind shears (dynamical instability) coincide with the PMSE enhancements. It is clear that the neutral turbulence is not a dominant factor in the formation of PMSE layers, but the strong turbulent activity can certainly modulate the strength of radar signal on the pre-existing PMSE layers.
Part II. In the second part of my presentation I am going to talk about developing a concept and technique for the processing of digital photographs of noctilucent clouds (NLC). Up to now there are a lot of digital materials on the NLC appearance. The photo-registration of NLC can provide useful information on NLC characteristics, on the gravity and planetary wave activity in the mesopause. But at the same time there is absolutely no both a strategy and technique how to process the photos, to extract the parameters of noctilucent clouds and wave characteristics. I suggest the first version of a new concept and technique on the statistical research of noctilucent clouds with digital photographs.Created 2004-12-06 16:31:51 by Rick McGregorLast changed 2004-12-06 16:31:51 by Rick McGregor