DISTRIBUTIONS OF PHYTOPLANKTON BLOOMS IN THE SOUTHERN-OCEAN

A regional pigment retrieval algorithm for the Nimbus-7 Coastal Zone C olor Scanner (CZCS) has been tested for the Southern Ocean. The pigmen t concentrations estimated with this algorithm agree to within 5 perce nt with in situ values and are more than twice as high as those previo usly reported. The CZCS data also revealed an asymmetric distribution of enhanced pigments in the waters surrounding Antarctica; in contrast , most surface geophysical properties are symmetrically distributed. T he asymmetry is coherent with circumpolar current patterns and the ava ilability of silicic acid in surface waters. Intense blooms (> 1 milli gram of pigment per cubic meter) that occur downcurrent from continent al masses result from dissolved trace elements such as iron derived fr om shelf sediments and glacial melt.