Geostrophic Current Balance: 2D Field Map

This is the 2D counterpart to the 3D geostrophic-balance simulator, computed independently from real oceanographic scales rather than a flattened render of a 3D mesh. It draws the sea-surface-height anomaly directly as a top-down colour field with contour rings, releases a ring of water parcels on its flank, and integrates each one under the real pressure-gradient force and Coriolis force (plus a small spin-down drag) using Earth's actual rotation rate and gravitational acceleration. A transect strip beneath the map — a genuinely 2D-native view with no 3D equivalent — plots the height profile and the geostrophic current speed along a straight line through the feature's centre, so you can read the balance as a graph as well as watch it in the plan view. Adjust latitude, height anomaly, feature radius and drag to see how each reshapes the resulting current.