Continental Shelf Research 25 (2005) 539–555 Modification to the atmospheric correction of SeaWiFS ocean colour images over turbid waters S.J. Lavender a,b,Ã , M.H. Pinkerton c , G.F. Moore d,b , J. Aiken d,b , D. Blondeau-Patissier d a School of Earth, Ocean and Environmental Sciences (SEOES), University of Plymouth, Plymouth Devon, UK b Centre for Observation of Air-Sea Interactions and Fluxes (CASIX) c National Institute of Water and Atmospheric Research (NIWA), PO Box 14901, Wellington, New Zealand d Plymouth Marine Laboratory, Prospect Place, Plymouth PL1 3DH, UK Received 23 July 2002; received in revised form 14 September 2004; accepted 1 October 2004 Available online 31 December 2004 Abstract The successful exploitation of remotely sensed observations of water colour in the coastal zone requires atmospheric correction methods that can determine water reflectance from top-of-atmosphere radiometric measurements over waters containing significant non-phytoplanktonic particulate material. These so-called Case II waters often have significant water leaving radiance at near infra-red (NIR) wavelengths which invalidates conventional ‘‘dark pixel’’ atmospheric correction procedures, including those using the Siegel-type NIR iterative-correction scheme. A coupled ocean-atmosphere model is described that solves for water-leaving radiance and atmospheric path radiance over Case II turbid waters from measurements by the NASA ocean colour satellite sensor, SeaWiFS. The theoretical basis of this model is described, together with its implementation within the SeaWiFS data processing system, SeaDAS. The resulting products are validated using five test images of European waters, where the modified atmospheric correction leads to significant increases in normalised water leaving-radiances across the whole spectrum and to fewer negative water leaving radiances. r 2004 Elsevier Ltd. All rights reserved. Keywords: SeaWiFS; Ocean colour; Case 2; Atmospheric correction; Suspended sediment; Geosensing 1. Introduction Satellite remote sensing of ocean colour is the only way at present to measure synoptically wide- area ocean properties such as phytoplankton abundance, the distribution of suspended particu- late matter (SPM) and absorption by coloured ARTICLE IN PRESS www.elsevier.com/locate/csr 0278-4343/$-see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.csr.2004.10.007 Ã Corresponding author. School of Earth, Ocean and Environmental Sciences, University of Plymouth, Portland Square, Plymouth PL4 8AA, UK. Tel.: +44 1752 232460; fax: +441752232406. E-mail address: s.lavender@plymouth.ac.uk (S.J. Lavender).