Eddy detection and tracking algorithms are applied to both satellite altimetry and a
high‐resolution (dx = 5 km) climatological model solution of the U.S. West Coast to study
the properties of surface and undercurrent eddies in the California Current System.
Eddy properties show remarkable similarity in space and time, and even somewhat in
polarity. Summer and fall are the most active seasons for undercurrent eddy generation,
while there is less seasonal variation at surface. Most of the eddies have radii in the range
of 25–100 km, sea level anomaly amplitudes of 1–4 cm, and vorticity normalized by
ƒ amplitudes of 0.025–0.2. Many of the eddies formed near the coast travel considerable
distance westward with speeds about 2 km/day, consistent with the β effect. Anticyclones
and cyclones show equatorward and poleward displacements, respectively. Long‐lived
surface eddies show a cyclonic dominance. The subsurface California Undercurrent
generates more long‐lived anticyclones than cyclones through instabilities and
topographic/coastline effects. In contrast, surface eddies and subsurface cyclones have
much more widely distributed birth sites. The majority of the identified eddies have
lifetimes less than a season. Eddies extend to 800–1500 m depth and have distinctive
vertical structures for cyclones and anticyclones. Eddies show high nonlinearity
(rotation speed higher than propagation speed) and hence can be efficient in
transporting materials offshore