Subsurface phytoplankton vertical structure from lidar observation during SCS summer monsoon onset.

Abstract

Subsurface phytoplankton vertical structure was observed for the first time by lidar during the onset of the SCS summer monsoon. Based on the lidar data that were obtained by continuous day-and-night measurements over a two-week period, a hybrid retrieval method to determine the vertical structure of the seawater chlorophyll-a concentrations using lidar data was proposed. We compared the data obtained from the lidar retrievals with the ocean color data and studied the spatial variations and hourly diurnal variations in the subsurface chlorophyll-a maximum layer (SCML). The significant changes in the depth of the SCML in the SCS may be due to the variations in light availability and nutrient supply during the onset of the SCS summer monsoon. The preliminary results indicated that lidar measurements allow the submesoscale oceanic dynamics mechanisms to be understood from a new perspective.