Study On Ocean Color Element Derived From GOCI Sensor In Bohai And North Yellow Sea

This research evaluates the accuracy and quality of high temporal and spacial resolution satellite L1 B data in Bohai Sea and North Yellow Sea, which derived from the first geostationary ocean color satellite in the world—GOCI(Geostationary Ocean Color Imager). GOCI satellite data set is acquired from Jan. to Dec. in 2013.In this study, the process of atmospheric correction of GOCI is sketched by GDPS and ENVI software respectively, and then the higher spacial resolution data derived from HJ sensor and survey data is utilized to discuss and verify the accuracy of Rrs data and ocean color production. The Rrs match-up results were well showed: highly correlated at band 5 and 6(R2=0.8067, 0.7384), moderate correlated at band 8(R2=0.5393).Chlorophyll-a, Suspended Particle Matter, Colored Dissolved Organic Matter were called three-component of ocean color. Rrs is a focus of this initialvalidation study, from which all other higher-levelproducts including Chl-a, SPM and CDOM were derived. The in-situ data match up showed: low correlated of Chl-aandCDOM(R2<0.4, R2<0.2), but SPM was significantly correlated(R2=0.87, MRE=35%). All of the in-situ data used to this study was at coastal zone, thus the conclusion could only on behalf of coast. Due to the high concentration of SPM, the reflected signals of Chl-aandCDOM on spectra were always concealed, so that the estimation of Chl-aand CDOM became more difficult. The study in the future would be concentrate to solving the challenging problem.This study area was significantly characterized by partition and seasonal variation. The common features among Chl-a, SPM and CDOM were: on the influence of terrestrial inputs, concentration descending from coastal zone to deep sea, from Bohai sea to Yellow sea. Seasonal variation coincided with previous study result: the highest Chl-a appeared in March due to the spring bloom, lowest in June, another high concentration period arise in autumn. This came into being Chl-a double period character, coincided with biological activity characteristics in north temperate sea. The seasonal variation of SPM showed: higher in winter and lower in summer. Sediment came from the upper reaches of the rivers, making Bohai bay and Laizhou bay become high SPM zone. CDOM, related with different marine environmental dynamic factors acted higher in autumn and lower in spring.Diurnalvariability of ocean color products in Bohai and North Yellow Sea were analyzed. Chl-a concentration reached the maximum at about 1:00(GMT), another peak was between 5:00 and 6:00. It kept steady in general. SPM largely ranged between 9~15(g/m3) in Bohai Sea, while ranged between 3~5(g/m3) in North Yellow Sea, the value and range scale apparently lower than Bohai Sea. CDOM kept increasing continuously of the whole day from 0:00, due to marine dynamic factors such as stormy waves, tidal current. At last, weexpected the atmospheric correction of GOCI could be better improved, extractedmore accurate data, which could provide data support to long & short term and rapid change of marine environment monitoring.