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 a nd map the vertical and horizontal structure of two cyclonic eddies in the lee of Hawaii. Depth-integrated nitrate+nitrite levels within the photic zo ne of the eddy cores were 3- to 15- fold higher than those observed for con trol 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 chromoph yte microalgae. Modeled primary productivity rates were up to twofold highe r at the stations within the eddies.