Lidar remote sensing of phytoplankton in the North-Western Atlantic

Results of shipborne lidar monitoring of chlorophyll-a concentration and phytoplankton photosynthetic activity in the North-Western Atlantic in April-June of 1990 are reported. The total length of the route of lidar sensing was 10500 km. The features of phytoplankton distributions at various spatial scales (about 1 km-local, 1-100 km-meso, 100-1000 km synoptic), as well as the relationship between these distributions and hydrological structures (eddies, rings, frontal zones, etc.) are analyzed. The mechanisms of diurnal rhythm of phytoplankton fluorescence were studied. Problems of correct interpreting fluorescent data are discussed, taking into account the dependence of chlorophyll-a fluorescence yield on physiological state of algal photosynthetic apparatus and the diurnal variations of fluorescence yield. >