Geophysical & Atmospheric Measurement Methods

← Back to Domain-Specific Families

Abstractions about measuring or modeling Earth's atmosphere, oceans, and subsurface, including atmospheric diagnostics such as convective available potential energy and thermal wind, geodetic and positioning techniques like free stationing and local tangent plane coordinates, and geophysical survey methods such as interferometric synthetic-aperture radar and vertical electrical sounding.

21 abstractions in this family — domain-specific abstractions that sit near one another in structural-signature space (k-means over structural-signature embeddings). Each is shown with its short description.

• Atmospheric sounding — Measurement of the vertical profile of atmospheric properties such as pressure, temperature, humidity, wind and trace constituents by in-situ or remote instruments.
• Chapman function — A dimensionless spherical-atmosphere integral giving slant-path column density relative to a vertical column for an exponentially stratified constituent.
• Convective available potential energy — The vertical integral of positive parcel buoyancy that estimates the maximum kinetic energy per unit mass available to atmospheric convection.
• Dynamic height — A geopotential-based vertical coordinate equal to a point's geopotential number divided by a fixed reference gravity, making equal values follow the same level surface and supporting large-scale water-flow applications.
• First break picking — Detection of the earliest coherent seismic arrival time on each recorded trace for near-surface velocity and timing analysis.
• Free stationing — A surveying setup that estimates an instrument's unknown position and orientation by observing multiple control points with known coordinates.
• Free-air gravity anomaly — The difference between observed and theoretical gravity after correcting measurement elevation to a reference level without compensating for intervening terrain mass.
• Frontolysis — The weakening or dissipation of an atmospheric front as the horizontal temperature gradient decreases.
• Geopotential spherical harmonic model — A global representation of a body’s gravitational potential as coefficients of spherical harmonic basis functions.
• Interferometric synthetic-aperture radar — A remote-sensing technique that compares the phase of two or more coherent SAR observations to estimate surface elevation, displacement or atmospheric path change along the radar line of sight.
• Isentropic analysis — A meteorological analysis that maps atmospheric variables on surfaces of constant potential temperature to diagnose approximately adiabatic air-mass motion.
• K-index (meteorology) — An atmospheric instability and moisture index combining temperatures and dew points at 850, 700, and 500 hPa to indicate potential for air-mass thunderstorms.
• Lemon technique — A weather-radar interpretation method that assesses relative thunderstorm updraft strength from echo-top, tilt, overhang, weak-echo-region and reflectivity-gradient trends.
• Local tangent plane coordinates — A location-dependent Cartesian frame tangent to an Earth reference ellipsoid, commonly oriented east–north–up or north–east–down.
• Plus–minus method — A reciprocal seismic-refraction analysis that combines travel times from opposite shot points to estimate refractor depth and velocity.
• Position line — A charted locus of possible observer positions consistent with one navigation observation, whose intersection with another independent locus yields a fix.
• Repetition method — A surveying procedure that measures the same horizontal angle successively around an instrument circle so accumulated readings can be divided and systematic effects reduced.
• Thermal wind — The vertical shear of balanced horizontal wind implied by a horizontal temperature gradient in a rotating stratified fluid.
• Tornado debris signature — A dual-polarization weather-radar pattern in which lofted nonmeteorological debris co-occurs with a tornadic velocity signature, providing strong evidence of an ongoing damaging tornado.
• Transient electromagnetics — A time-domain geophysical method that drives a pulsed primary electromagnetic field and measures the decay of induced subsurface currents to infer electrical structure.
• Vertical electrical sounding — A surface geophysical method that varies electrode spacing and measures apparent resistivity to infer one-dimensional changes in subsurface electrical properties with depth.