Validation of SeaWiFS data from around New Zealand Original Research Article

The near-surface concentration of chlorophyll-a (Ca) was measured during 11 research voyages around New Zealand between 1998 and 2000. Over 400 measurements of spectral normalised water-leaving radiance were made using a high precision profiling spectroradiometer. The data were used to assess the quality of remotely sensed measurements of Ca by the NASA ocean colour sensor, SeaWiFS, in New Zealand waters. The results in the open-ocean regions are consistent with a combination of negative biases in the Ca algorithm of ca. 20% (some regional dependency), and positive biases due to under-estimation of water reflectance towards the blue end of the spectrum by SeaWiFS.