The United States' National Aeronautics and Space Administration (NASA) has released animations of ocean circulation. Skeptics of animations should appreciate that these are extensively data-based. To quote
one of NASA's pages:
Data used by the ECCO [Estimating the Circulation and Climate of the Ocean] project include: sea surface height from NASA's Topex/Poseidon, Jason-1, and Ocean Surface Topography Mission/Jason-2 satellite altimeters; gravity from the NASA/German Aerospace Center Gravity Recovery and Climate Experiment mission; surface wind stress from NASA's QuikScat mission; sea surface temperature from the NASA/Japan Aerospace Exploration Agency Advanced Microwave Scanning Radiometer-EOS; sea ice concentration and velocity data from passive microwave radiometers; and temperature and salinity profiles from shipborne casts, moorings and the international Argo ocean observation system.These images reveal that the general patterns of gyres of surface currents (the large-scale asymmetric surface circulation across entire ocean basins) are modified at smaller scale by eddies (smaller tighter circles of circulation). This local and transient modification is sufficiently extensive that the large-scale currents can be difficult to recognize (much as mid-latitude weather can make climate hard to recognize). At an extreme, in places and at times, the currents effectively consist of tracks of eddies.
Two selected animations that are required reading for GEOL 3030 include
1. A one-minute temperature-coded animation of the currents This animation's long horizontal format requires moving from left to right to see everything, and its inexplicable split of the Pacific requires one to look at one side of the Pacific and then scroll to the other. It uses the classic equator-focused view of the world that does little justice to the higher latitudes, which are seen better on the "world tour" below. This animation is nonetheless amazing and deserves multiple viewings. Note that the most well-defined eddies originate where currents interact with land, whereas the open ocean regions have smaller and less pronounced eddies. Fun tidbits in this animation include watching the region at India's southern tip, and off southern Ceylon, for the changing direction of flow with the monsoons. Color indicates temperature and will change slightly with the seasons, and perhaps also with changing winds.
2. A three minute "Perpetual Ocean" world tour of ocean circulation This white-only (no-temperature-data) animation spins the globe under the viewer, perhaps most usefully to the South Pole to illustrate that the West Wind Drift really is an Antarctic Circumpolar Current. A "clock" at upper right shows the months represented by the animation as it progesses, further emphasizing that this is a data-based construct. Flickering brightness presumably results from local changes in current speed with stronger and weaker winds, and winds of changing direction.
More complete NASA sources that may be of interest include
Many thanks to Mary Fiore for leading her aged professor toward this new resource!