Potential of MIMOSA to detect deep stratospheric intrusions associated with severe weather over the Mediterranean Basin
Over the Mediterranean area, the intensification of surface lows and the occurrence of extreme events is often associated with the presence of southward stratospheric intrusions. MIMOSA, "Modele Isentropique de transport Mesoechelle de l'Ozone Stratosphérique par Advection", is a high-resolution potential vorticity (PV) advection model that performs calculations based on the ECMWF winds, providing PV fields on isentropic surfaces. This model was initially designed to interpret the observations of ozone laminae in lidar profiles, especially at Observatoire de Haute-Provence (OHP, 44°N, 5.7°E), and to support the planning of an ozone lidar onboard an aircraft, and has been extensively validated in the 350 to 675 K potential temperature range.
We will however show that MIMOSA is able to detect and track the deep stratospheric intrusion associated with the extreme precipitation event that occurred over Algiers, on 9-10 November 2001. The dominant feature for this event was a deep, elongated and narrow PV intrusion with an axis in the NE-SW direction that evolved prior to the rapid cyclogenesis. The coupling of this upper-level system with warm air over the Mediterranean led to intense winds and subsequently precipitation and floods. MIMOSA PV fields down to the 300K isentrope will be discussed for the whole period, together with the corresponding ERA-40 fields. This study emphasizes the ability of such a model to identify deep stratospheric intrusions.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020