Ocean waves are disturbances in the ocean surface, and have profound impacts on coastal communities, ocean circulation, and long-term climate systems. Perhaps the most dramatic and obvious waves are tsunamis, large waves caused by movements in the Earth’s crust that can wreak havoc on coastal communities and ecosystems. However, smaller disturbances are important too, such as Rossby waves, slow moving undulations in the ocean that are at most about 10cm in height. Despite their small size, Rossby waves can form and propagate over decades, influencing ocean circulation and weather systems like the El Nino Southern Oscillation for years at a time. 

Tsunamis are difficult to detect before they become highly dangerous, and Rossby waves are usually too small and slow-moving to identify. NASA missions like Surface Water and Ocean Topography (SWOT) help with both. SWOT uses radar to generate accurate and highly detailed snapshots of ocean height and movement, helping researchers monitor wave height and motion. The Jason series of satellites, launched in collaboration with the European Union, uses a similar system. 

Combined with decades of data from satellites, buoys, and ship observations, missions like these provide valuable insight on ocean waves across wide spatio-temporal scales. Detailed wave height data is important for detecting and responding to tsunamis, but also for understanding the wave patterns that shape climate and weather over decades.