Seminars

Lecturer: Peter Dalin
Date: 2014-10-23 10:00
Place: Aniara

Evidence of the formation of noctilucent clouds due to propagation of an isolated gravity wave caused by a tropospheric source

A unique case of propagating internal gravity wave through the layer of noctilucent clouds (NLC) is considered. The wave and NLC were observed in the Moscow region on the night of 18-19 July 2013. The present case is characterized by a single transient gravity wave which has formed a compact and thin layer of NLC at 84-85 km, with a characteristic horizontal scale of 65-70 km. The existence time of the gravity wave was about 1 h. Such a class of the isolated and compact gravity wave (connected with NLC) differs significantly from those previously observed. Hence we are introducing a new class of gravity waves in the summer mesopause: the Transient Isolated Gravity Wave (TIGW). Our model studies demonstrate that this particular TIGW had a tropospheric source connected to the passage of an occluded front and/or the point of occusion.

Created 2014-09-22 10:26:26 by Uwe Raffalski
Last changed 2014-10-14 15:56:50 by Uwe Raffalski