Observing the Air-Sea Interface in Hurricanes using Saildrones in 2024

Collecting observations in extreme conditions (i.e., within tropical cyclones) can be dangerous and challenging, yet extremely valuable. However, continuous and high-quality measurements collected simultaneously in the ocean and the atmosphere throughout extreme events are minimal. Recent improvements in observing technologies have significantly advanced our ability to collect these measurements to improve numerical prediction models, data assimilation schemes, and process understanding. Most notable of these advances are the increased usage of uncrewed systems (UxS), such as the saildrone, an uncrewed surface vehicle. Since 2021, NOAA and Saildrone have partnered to better observe hurricanes at the air-sea interface and transmit data in real time. In the 2023 Atlantic hurricane season, we collected over a million minutes of observations across 12 vehicles, including sustained winds for more than nine days of tropical storm force or stronger. In this presentation, I will focus on the successes, lessons learned, and challenges from the 2024 mission, as well as touching on the process studies and associated results. One such success is the multi-vehicle intercept of Hurricane Ernesto (2024), where two saildrones collected observations in opposing eye walls (NE and NW) within a short period. The resulting differences in the ocean's response in these two locations are notable and worthy of discussion, such as a nearly 2 ˚C difference in observed cooling.