Retrival chlorophyll-a of East China Sea based on MODIS remote sensing data

• 1、Key Laboratory of Geographic Information Science,Ministry of Education,East China Normal University,Shanghai,200241

Abstract：Oceanic chlorophyll concentration is the important indicator of phytoplankton and water quality. So chlorophyll concentration retrieval is meaningful for carbon cycle in ocean atmosphere, as well as for monitoring the ocean environment. Remote sensing has advantage of simultaneous observation with a large area, timeliness, economic and so on.Long-time series of satellite data can reveal the whole environment variety, which is the significant over the field measurement. In the research,we selects the MODIS1B data of Shanghai Ocean University MODIS satellite ground receiving station，include February 15, February 28 and May 7,2008. At first, pre-processing for MODIS I B formatted data is applied, which include geometric correcting with MOOIS satellite derived latitude and longitude data and visible band reflectance and infrared band radiance calibrating based on MODIS model with the sun angles. After the data pre-processing, the standard NASA experience model and its correction algorithm for chlorophyll-a concentration is used to get chlorophyll-a from MODIS band 9, 10 and 12 reflectance data, which are converted from band water-leaving radiance data after atmospheric correction. The result shows that: Distribution of concentration of chlorophyll-a has certain time and space characteristics, Specific performance is that concentration decreases from the near shore to open sea, ocean chlorophyll concentration changed little throughout the year, while current conditions offshore seasonal changed as well as by fresh water from the export of rivers, resulting in a significant seasonal variation of chlorophyll concentration.

Keywords： Remote sensing retrival MODIS East China Sea Chlorophyll-a Concentration