REMOTE-SENSING OF DIPOLE RINGS

Historical satellite-derived sea surface temperature (SST) data are re analyzed with a zebra color palette and a thermal separatrix method. T he new results from this reanalysis are as follows: a) Thirteen observ ational sequences of six rings from the Gulf Stream and the Brazil Cur rent, which have historically been interpreted as solitary vortices or monopoles are shown to have a dipolar character; b) some of these dip ole rings have been observed in the open ocean, thereby eliminating th e possibility that they are sustained by topographic interactions with the continental slope; c) whether interacting with other features or evolving as isolated circulations, dipoles are seen to rotate within a relatively narrow range of approximately 4-8 degrees day(-1) (interac ting) and 10-15 degrees day(-1) (isolated); and d) feature tracking de lineates energetic fluid in both vortices and eliminates the possibili ty of interpreting dipole rings as transient features produced by acti ve monopoles and patches of entrained fluid.