'Joint application of the SeaWiFS ocean color data and shipborne sea water laser induced fluorescence spectra measurements for monitoring phytoplankton communities'

摘要

Phytoplankton communities monitoring problems are very important now because of the phytoplankton plays a vital part in the organic matter reproduction processes in the ocean and in the gaseous exchange processes within ocean-atmosphere system. It is well known that the ocean color remote sensing is very successful to retrieve the chlorophyll-a concentration spatial distribution in the upper sea water layer. But, for the sea water case two it is necessary to carry out the comparative analysis of the ship's and satellite's measurements to develop the regional algorithms to retrieve the pigment concentrations from the satellite's data. The method of the laser induced fluorescence (LIF) was used to measure the chlorophyll-a concentration distribution and to carry out of the comparative analysis with the SeaWiFS data into the upper sea water layer. It was possible to carry out continuously measurements from the moving ship with spatial resolution about 200 meters by LIF. It provides the high reliability of the spatial distribution chlorophyll-a concentration measurements comparison with the sampling water measuring, especially in the case a high gradients taking place, for example, in frontal zones, upwelling and so on. Such comparative analysis allows us to develop the regional algorithms for the some regions of the sea of Okhotsk. The results of the application of the LIF method for phytoplankton communities state monitoring and for dissolved organic matter reproduction processes investigations by phytoplankton cells are presented. It is shown that there is the linear functional dependence between chlorophyll-a concentration and fluorescence part DOM during algae bloom on the base of the analysis of the great number of the LIF spectra measured in the various regions of Ocean. This correlation is retained for the large spatial scales. It may be evidence that the phytoplankton communities are in coherent state (in a sense of the DOM reproduction) during algae bloom. Out of blooming periods the correlation between chlorophyll-a concentration and fluorescence part DOM is retained for small spatial scales (local blooming). It is possible to carry out of the phytoplankton communities monitoring by DOM reproduction rates not only LIF spectra but using SeaWiFS data.