Program

To understand the role of the Mesoscale Convective System (MCS) in climate change, it is necessary to systematically document the variability of MCS features in the world on global scales. Despite the many studies published in previous, we still do not have a clear understanding of MCS limited by the observation and identifying methods. In this study, an enhanced algorithm has been developed for tracking MCS, with the application of Kalman Filter based on the classical over-lapping method. This algorithm adds the Kalman Filter into the classical over-lapping method, which can effectively improves the MCS tracking performance. By estimating MCS moving speeds and directions through historical observations, the application of Kalman Filter robustly tracking fast-moving MCS. The 20-year tropical MCS feature database has been developed based on this automated algorithm by using satellite infrared images of Cloud Archive User Service (CLAUS) project. With MCS properties included through its lifetime, the longtime database offers the potential to analyze MCS in a comprehensive perspective. As this MCS tracking algorithm is on public release, researchers can adjust the criteria for delicate study of interested regions and periods. Analysis of tropical MCSs derived from the database, examines the multi-variable feature of MCS distribution and variation. In terms of absolute MCS spatial distribution, these five regions: the Inter-Tropical convergence zone (ITCZ), the South Pacific convergence zone (SPCZ), the eastern north Indian Ocean, the middle Africa and the South America have the most frequent and intense MCSs. Globally, MCS has a maximum genesis at 1500–1800 local solar time (LST) and a minimum around 0900–1200LST. Over land, the diurnal variation of MCS genesis number shows similar variation as the global. Over sea, the diurnal variation is not so obvious compared with that over land.Time series of monthly MCSs number shows a sharp decrease in 1995, and remained at a nearly lower constant level after that compared with the period before 1995. MCS intensity, size and duration also have obvious variation during the period around 1995.