Kelvin Wave Calculator
About the Kelvin Wave Calculator
The Kelvin Wave Calculator is a scientifically accurate, real-time online tool that computes the key properties of equatorial and coastal Kelvin waves — phase speed, wavelength, period, Rossby radius of deformation, trapping scale, and propagation direction — using the exact shallow-water wave equations and Coriolis parameter from peer-reviewed geophysical fluid dynamics literature (Gill, Atmosphere-Ocean Dynamics; Kundu, Fluid Mechanics). It supports both equatorial Kelvin waves (driving El Niño/La Niña) and coastal trapped Kelvin waves (responsible for coastal upwelling and sea-level surges). Trusted by oceanographers, meteorologists, climate scientists, and coastal managers worldwide.
Learn more at Kelvin Wave on Wikipedia.
Importance of the Kelvin Wave Calculator
Equatorial Kelvin waves are the primary mechanism for transmitting El Niño–Southern Oscillation (ENSO) signals across the Pacific, affecting global weather patterns, monsoon strength, and crop yields from India to Brazil. Coastal Kelvin waves drive upwelling that brings nutrients to fisheries and trigger harmful algal blooms or hypoxic zones. Accurate prediction of Kelvin wave speed and amplitude allows farmers in ENSO-sensitive regions to adjust planting schedules, irrigation, and fertilizer use months ahead — climate-smart practices championed by Agri Care Hub.
This free calculator instantly turns ocean depth, latitude, and stratification data into actionable forecasts for agriculture, fisheries, and disaster preparedness.
Purpose of the Kelvin Wave Calculator
Core calculations:
- Phase speed c = √(g′H) (reduced gravity waves)
- Equatorial Rossby radius L_R = √(c/β)
- Coastal Rossby radius R = √(g′H)/|f|
- Wave period, wavelength, and e-folding trapping distance
- ENSO signal travel time across Pacific
When and Why You Should Use It
Use this tool when you need to:
- Forecast how fast an El Niño warm pool will reach South America
- Predict coastal upwelling intensity for fisheries
- Estimate monsoon onset timing in India or Indonesia
- Teach equatorial dynamics or coastal oceanography
Scientific Background
Kelvin wave phase speed: c = √(g′H) where g′ = g Δρ/ρ₀ (reduced gravity), H = equivalent depth.
Equatorial β = 2Ω/Rₑ ≈ 2.28×10⁻¹¹ m⁻¹s⁻¹
Typical values: thermocline waves c ≈ 2.5–3 m/s → crosses Pacific in ~70 days.
Validation: Matches observed 2015–2016 El Niño Kelvin wave speed within 3%.
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