SS3.03 Recent Advances in Coastal and River Plume Remote Sensing
Date: Thursday, June 13, 2002
Time: 3:15:00 PM
Location: View Royal
 
SchallesJF, Creighton University, Omaha, USA, jfsaqua@creighton.edu
Yacobi, Y, Z, Kinneret Limnology Laboratory, Tiberias, Israel, yzy@ocean.org.il
Alberts, J, J, School of Marine Programs, University of Georgia, Athens, USA, jalberts@imap.arches.uga.edu
Takacs, M, , University of Georgia Marine Institute, Athens, USA, 
 
FIELD REFLECTANCE SPECTRA FROM THE OPTICALLY COMPLEX WATERS OF COASTAL GEORGIA: CLASSIFICATION AND ALGORITHM ISSUES FOR REMOTE SENSING
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We measured water reflectance in the optically diverse estuarine mixing zones and offshore plumes of the Altamaha, Ogeechee, Saint Marys, and Satilla Rivers in Georgia between 1997 and 2000. Chlorophyll a, total and organic seston, dissolved organic carbon, UV absorbance, and attenuation spectra of filtered and unfiltered samples were measured for approximately 140 stations (secchi disk transparency range of about 20 – 500 cm). Wide variations in optically active constituents were found. Strong longitudinal and inter-river differences were present in water reflectance. Upstream, black water river segments produced reflectance spectra of low magnitude with a notable absence of peaks and troughs whereas clay dominated stations (esp. Altamaha River) had relatively high albedo and amplified pigment absorbance features. The positions and magnitudes of the mid-500 nm “green peak” and a near infrared peak near 700 nm were correlated with pigment and seston quantities. Independent variations in seston and algal pigment restricted the ability to estimate chlorophyll from reflectance spectra. Procedures to produce different optical classes of river and coastal waters appear more promising than algorithms developed to quantify constituents with high precision.