Biological enhancement at cyclonic eddies tracked with GOES thermal imagery in Hawaiian waters

In November 1999, ship and satellite platforms were used to track, target and map the vertical and horizontal structure of two cyclonic eddies in the lee of Hawaii. Depth-integrated nitrate+nitrite levels within the photic zone of the eddy cores were 3- to 15- fold higher than those observed for control stations. The depth and magnitude of the deep chlorophyll maximum were significantly elevated in the more mature of the two eddies. HPLC analyses revealed that the enhanced chlorophyll was largely contributed by chromophyte microalgae. Modeled primary productivity rates were up to twofold higher at the stations within the eddies.