Recorded presentation8.2
Mini-holes and their opposites: The role of barotropic instabilities in their displacements
H. Teitelbaum, Laboratoire de Météorologie Dynamique, Paris, France; and M. Moustaoui
Localized decrease of total ozone (mini-hole) very often appears accompanied by the opposite phenomenon, a localized increase of total ozone with a size similar to that of the mini-hole. This dipolar structure is explained by the fact that when Rossby waves distort the polar vortex edge, they give rise to two anomalies: an anti-cyclonic and a cyclonic one. Isentropic surfaces are uplifted above the anti-cyclonic anomaly, ozone is diluted, and the total ozone column decreases locally. Above the cyclonic anomaly the isentropic surfaces are down-lifted, ozone concentrates, thus the total ozone column increases locally. Moreover it is shown that when the cyclonic/anti-cyclonic edge tilts with respect to the meridians, barotropic instabilities appear and contribute to the temporal displacements of the dynamics anomalies. The localized columnar ozone variations follow from this mechanism. Recorded presentation
Session 8, Stratospheric Ozone and Tropospheric Weather-II
Thursday, 24 January 2008, 11:00 AM-12:15 PM, 230
Previous paper Next paper