P. Bonasoni et al., Stratospheric ozone intrusion episodes recorded at Mt. Cimone during the VOTALP project: case studies, ATMOS ENVIR, 34(9), 2000, pp. 1355-1365
Continuous measurements of ozone concentrations performed at baseline stati
ons on high mountain summits allow stratosphere-troposphere exchange events
to be monitored and their variability over small scales to be studied. In
this paper we present two characteristic episodes related to lower stratosp
here/upper troposphere vertical transport registered at Mt. Cimone during t
he VOTALP project and we highlight the use of carbon monoxide (CO) and carb
on dioxide (CO2) as non-conventional tracers of lower stratospheric air mas
ses, In this way, stratosphere-troposphere exchange events transporting hig
h ozone concentration into the troposphere have been identified by an accur
ate analysis of the CO and CO2 behaviour. Moreover, three-dimensional ensem
ble trajectories, satellite maps (water vapour and total ozone), ground-bas
ed ozone measurements and ozone-soundings have been analysed together with
conventional tracers as Be-7 and relative humidity as well as the normalise
d fraction f(Be-7, Pb-210) in order to fully characterise the examined even
ts. (C) 2000 Elsevier Science Ltd. All rights reserved.