手法を比較

	調和解析 (Tidal Harmonic Analysis)	CTDプロファイリング	地衡流速
分野	海洋学	海洋学	海洋学
系統	Process / pipeline	Process / pipeline	Process / pipeline
提唱年	1867	1977	1942
提唱者	William Thomson	Neil Brown	Harald Sverdrup
種類	fourier-analysis	instrumental	theoretical-method
原典	Godin, G. (1972). The Analysis of Tides. University of Toronto Press.	UNESCO/IOC. (1991). Processing of oceanographic station data. UNESCO Technical Papers in Marine Science, 60.	Sverdrup, H. U., Johnson, M. W., & Fleming, R. H. (1942). The Oceans: Their Physics, Chemistry, and General Biology. Prentice-Hall.
別名	Tidal Constituents, Harmonic Tidal Prediction	CTD, Rosette Sampling	Geostrophic Current, Thermal Wind Equation
関連	3	3	3
概要	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.	Conductivity-Temperature-Depth (CTD) profiling is the primary method for measuring vertical profiles of seawater properties in oceanography. Developed by Neil Brown in 1977, CTD instruments are equipped with sensors for conductivity, temperature, and pressure (depth), and are typically mounted on water-sampling rosettes. CTD profiling provides essential hydrographic data that characterizes water mass structure, stratification, and circulation patterns.	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.