Thermohaline circulation · AMOC · Ekman transport · Wind-driven gyres · Ocean conveyor
Simulate the global ocean circulation driven by temperature and salinity gradients (thermohaline) and wind stress (Ekman transport). See how the Great Ocean Conveyor Belt redistributes heat globally and how climate change threatens AMOC stability.
Ocean density ρ = ρ₀(1 − α(T − T₀) + β(S − S₀)) depends on temperature (T) and salinity (S). Cold, salty water is denser and sinks at high latitudes (North Atlantic, Antarctic). This drives the Great Ocean Conveyor — water that sinks in the North Atlantic returns to the surface in the Pacific 1,000 years later.
Wind stress drives Ekman transport perpendicular to wind direction: V_E = τ/(ρf) where f = 2Ω·sinφ is the Coriolis parameter. This creates the five major subtropical gyres. Geostrophic flow v_g = −(1/ρf)·∂P/∂x balances pressure gradient and Coriolis force, giving the swirling gyre pattern.
The Atlantic Meridional Overturning Circulation (AMOC) currently carries ~18 Sv (1 Sv = 10&sup6; m³/s). Freshwater from melting ice dilutes North Atlantic salinity, reducing density and potentially shutting down sinking. Models suggest tipping points may exist; a collapse would cool northern Europe dramatically and shift monsoon patterns.
Use presets to compare Modern, Ice Age (stronger thermohaline), +2°C warming (weakened AMOC), and Collapse scenarios. Slide the Freshwater Forcing to simulate ice melt. Toggle between surface and deep circulation layers. Watch the AMOC strength meter respond to temperature and freshwater changes.