1 cpy harmonics of transport along the variance ellipse major axes
Average annual cycle velocity anomalies were decomposed into components along the major and minor axes of the variance ellipses (see plot 1.f.3). A 1 cpy harmonic of the component along the major axis was found. This combines the u and v components of velocity.
The phase shown is ambiguous by 180° because zero can be chosen in either direction along the major axis. It was chosen here so that the phase is the date of maximum westward interior or southward coastal velocity.