Merepinnad

Merepinnad is the Estonian term for the sea surface, the interface between the ocean and the atmosphere. It denotes the uppermost layer of seawater that is directly affected by wind and solar radiation and participates in exchanges of heat, moisture and gases with the air above. The sea surface is a dynamic boundary: waves range from small ripples to large swells, foam and spray form and dissipate, and surface roughness governs the transfer of momentum between air and sea.

Key properties of merepinnad include temperature, salinity, sea surface height and surface roughness. These variables are shaped by wind speed and direction, air temperature, solar heating, evaporation and precipitation, tides and ocean currents. The surface mediates processes such as heat storage, evaporation, gas exchange (notably carbon dioxide), and the formation of weather fronts and short-term atmospheric phenomena.

Measurement and observation of merepinnad rely on both satellite remote sensing and in situ sensors. Satellites provide sea surface temperature, sea surface height, ocean color and surface roughness estimated from radar backscatter. In situ observations from buoys, ships and coastal radar supplement these data with winds, currents and detailed surface conditions. Data on merepinnad underpin weather forecasting, climate monitoring, maritime navigation and marine ecosystem studies.

In scientific contexts, merepinnad is treated as a boundary layer rather than a volume, with emphasis on air–sea interaction, surface dynamics and the exchange processes that link the atmosphere to the deeper ocean.