OCEAN · SEA LEVEL (ALTIMETRY)

Sea Level (Altimetry)

How high or low the sea surface is right now versus its long-term average — a live global map of sea-level anomaly in metres, measured from space by radar altimeters to within a centimetre or two. The sea is not flat: it bulges over warm, light water and dips over cold, dense water, and it piles and slumps as currents and eddies push it around. Reds stand higher than normal (warm-core eddies, the El Niño bulge), blues lower. The same satellite altimetry that revealed the global rise of the ocean — a measurement no keyless raster on this canvas provides. Updated daily.