Collaborative Research: Convective Processes in the Tropics Across Scales

In the tropics, rainfall events can range in size, from small in size (such as an individual thunderstorm) to very large in size (such as a monsoon). It is difficult to observe or simulate the small-sized details and the large-sized patterns at the same time. As a result, many aspects of clouds, storms, and rainfall are not fully understood. It is also important to note that tropical rainfall events have an influence not only within the tropics, but can also excite weather patterns that move northward out of the tropics and influence the continental United States. The research projects here will improve our understanding of the interaction of small-sized details and large-sized patterns. The project activities will benefit society in several ways through advancing discovery and understanding while promoting teaching, training, and learning. Particular benefits include: (i) developing a competitive STEM workforce by training undergraduate students, a graduate student, and a postdoc; (ii) outreach to K-12 schools to familiarize students with STEM research and motivate them to pursue STEM careers; (iii) broadening the participation of underrepresented groups by mentoring undergraduate students in conducting research projects; and (iv) improving the well-being of individuals in society by conducting research that is aimed at cloud and rainfall processes that influence humanity, since a better understanding of these processes can help to improve modeling and predictions and benefit society. Moist convective processes in the tropics involve a vast range of scales. As a result, difficulties arise in observations due to instrument constraints and in simulations due to computational cost, and many convective phenomena are not fully understood. Some examples include the influence of island coastlines and topography on the diurnal cycle of tropical rainfall, the interaction of convectively coupled equatorial wave events and tropical islands, and entrainment and mixing processes. For simulations of these processes to be viable while modeling precipitating clouds across scales, recent results of the preliminary studies will be leveraged to use adaptive mesh refinement and non-column-based grids. These methods allow the investigation of processes that would be difficult or impossible to simulate with uniformly-spaced Cartesian grids. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.