GATEway to the Future: Observing, Understanding, and Modeling the Air-Sea Transition Zone (ASTZ)

Building on 50 years of scientific and engineering progress sparked by the 1974 GATE Atlantic tropical field program, we are now embarking on a paradigm shift in observing, understanding, and modeling how the ocean and atmosphere interact. In the past, “Air-Sea Interaction” has been considered an open-ended subtopic of either oceanography or atmospheric science, or in some cases has been assumed to refer to finescale interfacial physics. Instead, the international science community now recognizes the power and importance of considering the Air-Sea Transition Zone (ASTZ), which refers to and spans the oceanic boundary layer, atmospheric boundary layer, and their interface together as a single coupled coevolving entity. The ASTZ connects to the thermocline and deep ocean via ocean mixing, while the ASTZ also connects to the free atmosphere via clouds, precipitation, and turbulence rooted in the atmospheric boundary layer. This talk reviews advances and recommendations in technology, understanding, and modeling of the Air-Sea Transition Zone, from the foundational GATE 1974 experiment to the present (The Global Atmospheric Research Program's (GARP) Atlantic Tropical Experiment). In light of GATE 1974, we show how observing and modeling the ASTZ impacts the prediction skill and predictability of tropical clouds, precipitation, radiation, ocean processes, and global cycles of energy and water.