Siinuslained

Siinuslained is a term used in Estonia to describe a phenomenon related to the Baltic Sea. It refers to unusual wave patterns that can occur under specific meteorological conditions. These patterns are not typical wind-driven waves but are thought to be generated by atmospheric pressure fluctuations interacting with the water surface. The name "siinuslained" literally translates to "sine waves" in Estonian, suggesting the sinusoidal shape of these wave formations.

These events are relatively rare and are often observed during periods of rapid barometric pressure changes, such as those associated with strong low-pressure systems passing over the Baltic Sea. The exact scientific mechanism behind the formation of siinuslained is still a subject of research, but it is believed to involve resonance between atmospheric pressure oscillations and the water body. Unlike seismic sea waves (tsunamis), siinuslained are not caused by earthquakes or underwater landslides.

Siinuslained can manifest as long, regular swells that may appear out of proportion to the prevailing wind conditions. They can sometimes cause localized flooding or unusual water level changes along the coast. While not typically destructive, their appearance can be striking and has led to considerable local interest and occasional scientific investigation. The term is primarily used within Estonia and is not widely recognized internationally.