@conference{Papadopoulou2015,

title = {Deriving euphotic zone depth in the North Aegean Sea from field and MODIS ocean colour measurements},

author = {A. Papadopoulou and P. Drakopoulos and S. Psarra and A. Clive Banks and A. Karageorgis and A. Lagaria and N. Spyridakis and V. Zervakis , },

url = {https://www.researchgate.net/publication/306449205_Deriving_euphotic_zone_depth_in_the_North_Aegean_Sea_from_field_and_MODIS_ocean_colour_measurements},

year  = {2015},

date = {2015-05-01},

address = {Mykonos Island, Greece },

organization = {Fifth International CEMEPE and SECOTOX Conference},

abstract = {Euphotic zone depth (Zeu) is defined as the depth at which the photosynthetically active radiation (PAR) value is 1% of the surface value. In this work, three approaches were used to estimate Zeu from field data (in the North Aegean Sea): (a) the Chl-approach, where surface chlorophyll-a values were determined via the high performance liquid chromatography (HPLC) and the fluorometric technique, (b) the PAR-approach, where photosynthetically active radiation was measured with a hyperspectral irradiance meter and (c) the Reflectance-approach, in which surface reflectance values were produced from the in situ downwelling spectral irradiance and upwelling spectral radiance field measurements. Using the Seawifs Data Analysis System (SeaDAS), MODIS daily Level-2 Zeu datasets were produced with two different bio-optical algorithms, which were based on chlorophyll-a concentration (satellite Chl-approach). The comparison of field and satellite Zeu values showed that MODIS tended to underestimate the Zeu for all different approaches. In more detail, the two bio-optical algorithms were found to underestimate Zeu values by ~20-31% and ~18-21% when compared to field measured Zeu data via Chl-approach and PAR-approach, respectively. The percentage range of the underestimation of the Zeu satellite values compared with the one obtained from the field Zeu values via the Reflectance-approach, was found particularly small (~1-5%), a fact that explains the differences in the products as delivered by space agencies. Furthermore, the high uncertainties between field and satellite Zeu measurements require new approaches for ocean colour algorithms in the North Aegean Sea.},

keywords = {chlorophyll, euphotic zone, MODIS, ocean colour, remote sensing},

pubstate = {published},

tppubtype = {conference}

}