Speaker: Kelly Nunez Ocasio, Assistant Professor, Department of Atmospheric Sciences, Texas A&M University

Host: Danielle Touma

Title: Novel Regional Modeling Approaches for Current and Future Tropical Weather and Climate

Abstract: Africa’s weather–climate system, including the African Easterly Jet (AEJ) and West African Monsoon, strongly influences high-impact weather across Africa and the tropical Atlantic. However, how this system responds to climate warming remains unclear due to limitations in global climate models. We address this using convection-permitting simulations with MPAS-A and a pseudo-global warming approach. Results show a northward-shifting and intensifying AEJ under mid-century warming, alongside increased monsoonal moisture. These changes alter the intensity and location of mesoscale convective systems (MCSs) and African Easterly Waves (AEWs), which can seed Atlantic tropical cyclones and cause significant impacts.

In the second part of the talk, I turn to Mesoamerica and the Caribbean—regions with complex hydroclimates and sparse observations. I will introduce the Mesoamerica Affinity Group (MAAG), an NSF NCAR-supported initiative promoting collaborative, high-resolution climate research. A key project includes a two-week convection-permitting MPAS-A simulation of Hurricane Maria (2017), using a variable-resolution mesh (15–3 km). Preliminary validation shows strong performance in simulating precipitation, the ITCZ, and low-level jets. This dataset, now publicly available via NCAR’s Research Data Archive, supports broader analysis of tropical cyclones and extreme rainfall events.

At Texas A&M, my group continues to explore how tropical systems across Africa, the Atlantic, Central America, and the Caribbean are evolving in a warmer, moisture-rich climate.