资源环境科技发展态势分析平台

This study analyses the characteristics and the spatio-temporal distribution of convective overshooting (COV) clouds in the Mediterranean using passive microwave observations from sounders onboard polar-orbiting satellites. COV has distinct microphysical properties that sets them apart within deep convective (DC) clouds, injecting high content of ice in mid to high troposphere (1 g m(-3) at 8 km in average). The ratio of COV to DC shows largest occurrences over continental Europe during summer (similar to 20% of DC cases), and mostly over the sea and coastal areas in autumn (similar to 13% of DC events). COV frequency presents interannual variation and spatial interannual variability in all seasons. COV preferred location follows a seasonal migration from land in summer to sea and coastal areas in autumn, and also occurs during winter, mostly over the sea. In continental areas the diurnal cycle of COV tends to peak in the afternoon during summer; it is less marked over the sea, yet it shows a slight preference for early morning and afternoon occurrences. The spatial resolution (similar to 20 km) of COV detection makes this database valuable for climatic studies.