Fine-scale layering on the edge of a stratospheric intrusion

Observations of vertical profiles of ozone, humidity, static stability and VHF radar vertical power at Aberystwyth (52 degreesN, 4 degreesW) on 21 Jun e 1996 revealed a pronounced layered structure at the western edge of a str atospheric intrusion, in a location where one would expect to see a tropopa use fold. Despite the 3 km depth of the observed ozone anomaly. it was not represented as a fold in the ECMWF potential vorticity analyses; nor was it evident as a laver of enhanced wind shear. Ozone lidar measurements sugges t that the fine-scale layering gave way to a single layer as the day progre ssed. Weak sporadic turbulence observed by the radar at the edge of the fol d showed some mixing between stratospheric and tropospheric air, (C) 2001 E lsevier Science Ltd. All rights reserved.