Observation of Mediterranean precipitating systems using AMSU
The potential of the Advanced Microwave Sounding Unit (AMSU) observations to identify and characterize precipitating systems in the Mediterranean region is explored.
Single channels or combination channels from AMSU module A are used to detect and locate southward stratospheric intrusions that are often associated with intensification of surface lows and occurrence of extreme events, while AMSU module B data are used to detect precipitating areas. Results are shown for selected cases studies of severe precipitation in the Mediterranean.
We found that AMSU-A channel 8 is suitable to identify high upper tropospheric potential vorticity associated with intrusions of stratospheric air. A combination of AMSU-B channels 3 and 5, in turn, is able to discriminate moderate to heavily precipitating areas with good agreement with TRMM rainfall product and independent ground-based precipitation data. We also investigated the applicability of a tropical deep convection threshold for the Mediterranean region.
This study is part of the framework of CYPRIM (Cyclogenesis and Intense Precipitation in the Mediterranean region), and the motivation for the approach presented here is the direct use of satellite data (as an alternative for reanalysis datasets) without relying on retrievals algorithms, to form a climatology of moderate to strongly precipitating systems.
We will proceed with the investigation of the relationship between such systems and upper level features that may be precursors of extreme events, establishing therefore a typology (of precipitating systems) based on their frequency, size and position relative to the upper level feature, for the Mediterranean region.
HyMeX – Hydrological cycle in the Mediterranean Experiment 2010-2020