Comparer des méthodes

	Analyse Lagrangienne par Dériveurs	Vitesse géostrophique
Domaine	Océanographie	Océanographie
Famille	Process / pipeline	Process / pipeline
Année d'origine	1985	1942
Auteur d'origine	Robert Davis	Harald Sverdrup
Type	instrumental	theoretical-method
Source fondatrice	Davis, R. E. (1985). Drifter observations of coastal surface currents during CODE: The method and descriptive view. Journal of Geophysical Research, 90(C3), 4741-4755.	Sverdrup, H. U., Johnson, M. W., & Fleming, R. H. (1942). The Oceans: Their Physics, Chemistry, and General Biology. Prentice-Hall.
Alias	Lagrangian Tracking, Drifter Analysis	Geostrophic Current, Thermal Wind Equation
Apparentées	3	3
Résumé	Drifter Lagrangian analysis tracks the motion of water parcels using surface drifters (buoys with attached drogues) to measure ocean currents directly. Developed by Robert Davis in the 1980s, this method provides direct observation of water parcel trajectories and enables estimation of eddy diffusivity, transport pathways, and mixing. Drifter data complement Eulerian (fixed-point) observations by capturing the Lagrangian perspective of fluid motion.	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.