On the laminated structure of ozone in the sub-tropical atmosphere

Ozone data recorded by balloon-borne sondes released at various sites around the world revealed that frequently the vertical ozone distribution in the stratosphere is remarkably laminated. Recently, measurements of ozone profiles near the winter polar vortex have shown strong laminae close to the vortex boundary. Also, a statistical study published recently has shown that laminae are most commonly found between 12 and 18 km at high latitudes in winter and spring in both hemispheres but they are not found in the tropics and are rarely observed in the subtropics. Ozonesonde ascents performed in Athens (37.9 deg N, 23.8 deg E) during the winter 1991-1992 in the framework of the European Arctic Stratospheric Ozone Experiment (EASOE) have shown that the lamination phenomenon was very frequently present in our region which is in contradiction with previous measurements at our latitudes. The characteristic minimum of ozone at 15 km has been also detected. Finally, the correlation of the occurrence of these two phenomena in relation with the circulation of air masses showed that the laminated profiles are connected in the lower stratosphere while the appearance of the ozone minimum around 15 km is connected with the influence of the subtropical jet-stream.