手法を比較

	地衡流速	エクマン輸送	調和解析 (Tidal Harmonic Analysis)
分野	海洋学	海洋学	海洋学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1942	1905	1867
提唱者	Harald Sverdrup	Vagn Walfrid Ekman	William Thomson
種類	theoretical-method	theoretical-method	fourier-analysis
原典	Sverdrup, H. U., Johnson, M. W., & Fleming, R. H. (1942). The Oceans: Their Physics, Chemistry, and General Biology. Prentice-Hall.	Ekman, V. W. (1905). On the influence of the Earth's rotation on ocean currents. Arkiv for Matematik, Astronomi och Fysik, 2(11), 1-52.	Godin, G. (1972). The Analysis of Tides. University of Toronto Press.
別名	Geostrophic Current, Thermal Wind Equation	Ekman Spiral, Wind-driven Transport	Tidal Constituents, Harmonic Tidal Prediction
関連	3	3	3
概要	Geostrophic velocity is the current driven by balance between the pressure gradient force and the Coriolis force, derived from the thermal wind equation. In most of the ocean away from the equator and coastal boundaries, geostrophic balance is an excellent approximation to the actual flow. Developed by Harald Sverdrup and colleagues in the 1940s, geostrophic velocity calculation from hydrographic data enables estimation of ocean currents without direct current measurements.	Ekman transport is the net volume flux of water driven by wind stress balanced with Coriolis force in the surface boundary layer. Derived by Vagn Walfrid Ekman in 1905 from the principle that wind stress is transmitted through the water column in a spiral pattern, Ekman transport is responsible for coastal upwelling and important oceanographic transports. The theory links surface wind patterns directly to ocean circulation.	Tidal harmonic analysis is a mathematical method that decomposes observed sea level or current time series into a sum of sinusoidal components with specific frequencies, amplitudes, and phases corresponding to astronomical tidal constituents. Developed by William Thomson (Lord Kelvin) in 1867, harmonic analysis enables prediction of tides and understanding of tidal dynamics in coastal regions.