Observations of Life Cycles of Global Mesoscale Convective Systems Using Cloud-Top Tracking

Mesoscale convective systems (MCSs) are crucial to the global hydrological cycle, bringing almost half of all yearly precipitation to some areas of the world. The differences in MCSs that develop over land, ocean, and coastal regions have not yet been clearly defined. Geostationary satellite data can be used to identify MCSs using PyFLEXTRKR, an open-source feature tracking software. In this study, it was found that MCSs predictably form over the Inter-Tropical Convergence Zone (ITCZ) and over significant topography such as the Andes and Rwenzori Mountains. On average, MCSs that form over land and coasts exhibit more explosive growth rates, within the first five hours of the MCSs lifetime, than do oceanic MCSs. This is likely due to the larger mean values of convective instability and wind shear found over land and coastal areas than ocean areas due to differing heating and friction. Among the most explosive MCSs at both the 90th and 99th percentiles, however, oceanic storms far outpace land and coastal MCSs with the fastest growth rates. Connections between mean and extreme MCS growth rates and instability are investigated.