Mesoscale convective systems over the Amazon basin. Part I: climatological aspects

ABSTRACT Mesoscale convective systems ( MCSs ) over the Amazon basin provide a large contribution to regional precipitation, which strongly influences the maintenance of unique ecosystems. Despite the importance of these MCSs , their characteristics are not well described in the literature. The present study uses a 14‐year long (2000–2013) data set of high‐resolution (4 km; 30 min) infrared satellite images to compile a climatology of MCSs that during the period of analysis were within the borders of the Amazon basin at some point in their lifespan. MCSs that originated over the continent and the ocean are considered separately. It is found that on average about 7200 continental and 50 oceanic MCSs occurred per year in the Amazon basin. The majority (minority) of continental (oceanic) MCSs completed their lifecycles between 3 and 5.5 h. These MCSs are studied separately from those with lifespan longer than 6 h. Continental and oceanic MCSs over the Amazon occurred primarily during austral summer and autumn–winter, respectively. The preferred regions and time for genesis of continental and oceanic MCSs are identified. The average area, propagation speed and direction of displacement for MCSs in the different stages of their lifecycle are also examined.