Euphotic zone depth, z(1%), reflects the depth where photosynthetic available radiation ( PAR) is 1% of its surface value. The value of z(1%) is a measure of water clarity, which is an important parameter regarding ecosystems. Based on the Case-1 water assumption, z(1%) can be estimated empirically from the remotely derived concentration of chlorophyll-a ([ Chl]), commonly retrieved by employing band ratios of remote sensing reflectance ( R-rs). Recently, a model based on water's inherent optical properties ( IOPs) has been developed to describe the vertical attenuation of visible solar radiation. Since IOPs can be near-analytically calculated from R-rs, so too can z(1%). In this study, for measurements made over three different regions and at different seasons ( z(1%) were in a range of 4.3-82.0 m with [ Chl] ranging from 0.07 to 49.4 mg/m(3)), z(1%) calculated from R-rs was compared with z(1%) from in situ measured PAR profiles. It is found that the z(1%) values calculated via R-rs-derived IOPs are, on average, within similar to 14% of the measured values, and similar results were obtained for depths of 10% and 50% of surface PAR. In comparison, however, the error was similar to 33% when z(1%) is calculated via R-rs-derived [ Chl]. Further, the importance of deriving euphotic zone depth from satellite ocean-color remote sensing is discussed.
Citation / Publisher Attribution
ZhongPing Lee, Alan Weidemann, John Kindle, Robert Arnone, Kendall L. Carder, Curtiss Davis. 2007. "Euphotic Zone Depth:Its Derivation and Implication to Ocean-Color Remote Sensing." Journal of Geophysical Research - Oceans. 112(C3):Article C03009. DOI 10.1029/2006JC003802. To view the published open abstract, go to http://dx.doi.org and enter the DOI.
© Copyright 2007, American Geophysical Union
ZhongPing Lee, Alan Weidemann, John Kindle, Robert Arnone, et al.. "Euphotic Zone Depth: Its Derivation and Implication to Ocean-Color Remote Sensing" Journal of Geophysical Research - Oceans
Vol. 112 Iss. C3 (2007)
Available at: http://works.bepress.com/kendall_carder/2/