Correlation and synchrony

These are distinct analyses: correlation describes covariation of continuous values; synchrony can compare occurrence, severity, timing or duration of states and events. Choose the quantity before choosing the operation.

Task	Implemented reference or workflow
Compare state occurrence, severity, timing and duration	Four synchrony primitives
Follow a complete observed state/event analysis	States and events notebook
Compare rolling upper/lower behavior	Median-split synchrony
Compare a cube with its center	Rolling tail dependence
Compare two aligned continuous fields	Climate and NDVI alignment requirements

v.correlation_cube is a reserved, unimplemented API. It does not return a correlation cube. For explicit xarray calculations, align CRS, spatial support, timestamps and missing-data semantics first. Matching dimension names alone does not establish comparability.