Comparison of MERIS, MODIS, SeaWiFS-derived particulate organic carbon, and in situ measurements in the South China Sea

ABSTRACT

Medium Resolution Imaging Spectrometer (MERIS), Moderate Resolution Imaging Spectroradiometer (MODIS), and Sea-viewing Wide Field-of-view Sensor (SeaWiFS) particulate organic carbon (POC) concentration products for the South China Sea (SCS) were compared with in situ data collected from October 2007 to December 2013. Spectral remote-sensing reflectance (R_rs,λ) was also measured to help understand POC algorithm performance. A strict comparison of the satellite-derived POC and in situ measurements showed that MERIS, MODIS, and SeaWiFS underestimated in situ values by 29.1, 11.7, and 31.5%, respectively. Similar results were obtained with a relaxed matching criterion. Through analysis of the causes of product uncertainty, the results suggested that satellite retrieval of R_rs,λ and the global POC algorithm both have an impact on inversion accuracy. However, the formulation of the POC algorithm seems to be more critical. When a regional algorithm was developed to obtain satellite-derived POC, both the strict and relaxed comparison results showed significant improvement, but for coastal waters, both algorithms had larger errors. Other factors affecting the comparison are also discussed.

Acknowledgements

We would like to thank NASA for the distribution of MERIS, MODIS, and SeaWiFS data product.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by National Natural Science Foundation of China grants [grant numbers 41376042, 41176035], the Natural Science for Youth Foundation [No. 41206029], the youth Foundation supported by South China Sea institute of oceanology Chinese academy of sciences [No. SQ201102], the open research Fund of State key Laboratory of Estuarine and Coastal Research [grant number SKLEC-KF201302], and the Open Project Program of State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences [No. LTOZZ1201].