An Optical Model for the Remote-Sensing of Absorption Coefficients of Phytoplankton in Oceanic/Coastal Waters

• 作者: Palanisamy Shanmugam Surya Prakash Tiwari
• 来源期刊: 遥感技术进展(英文)
• 学科: 地球科学
• 关键词: Remote Sensing PHYTOPLANKTON Absorption Bio-Optical Models Coastal WATERS MODIS-Aqua SEAWIFS Arabian Sea
• 年，卷（期）: ygjsjzyw,（2）
• 页码范围: 19-34
• 页数: 16页
• 分类号: P7

摘要

A new model for the remote sensing of absorption coefficients of phytoplankton aph (λ) in oceanic and coastal waters is developed and tested with SeaWiFS and MODIS-Aqua data. The model is derived from a rela-tionship of the remote sensing reflectance ratio Rrs (670)/Rrs (490) and aph (490) and aph (670) (from large in-situ data sets). When compared with over 470 independent in-situ data sets, the model provides accurate retrievals of the aph (λ) across the visible spectrum, with mean relative error less than 8%, slope close to unity and R2 greater than 0.8. Further comparison of the SeaWiFS-derived aph (λ) with in-situ aph (λ) values gives similar and consistent results. The model when used for analysis of MODIS-Aqua imagery, provides more realistic values of the phytoplankton absorption coefficients capturing spatial structures of the massive algal blooms in surface waters of the Arabian Sea. These results demonstrate that the new algorithm works well for both the coastal and open ocean waters observed and suggest a potential of using remote sensing to provide knowledge on the shape of phytoplankton absorption spectra that are a requirement in many inverse models to estimate phytoplankton pigment concentrations and for input into bio-optical models that predict carbon fixation rates for the global ocean.