Earth’s hidden balance: a persistent east–west albedo symmetry revealed
A 25-year CERES record reveals a unique and persistent east–west albedo symmetry around 27°E, where Eastern and Western Hemispheres reflect nearly identical solar radiation. The symmetry forms a triple balance: high-cloud reflection is stronger in the Eastern Hemisphere, low-cloud reflection dominates in the Western Hemisphere, and ice-free ocean fractions are nearly the same in both hemispheres, collectively maintaining similar reflectivity. Interannual variability of the symmetry tracks ENSO, implying a link to Walker circulation, while climate models (CMIP6) fail to reproduce this feature, highlighting gaps in cloud representation. The finding offers a new constraint for Earth system models and underscores the need for sustained radiation-budget observations amid climate change.