@conference{Papadopoulou2017,
title = {Determining the level of uncertainty between in situ and MODIS satellite-derived chlorophyll-α estimations in the optically complex North Aegean Sea waters},
author = {A. Papadopoulou and P.G. Drakopoulos and S. Psarra and A.P. Karageorgis and A. Lagaria and N. Spyridakis and Vassilis Zervakis},
url = {https://www.researchgate.net/publication/282824208_Estimating_chlorophyll_concentrations_in_the_optically_complex_waters_of_the_North_Aegean_Sea_from_field_and_satellite_ocean_colour_measurements},
year = {2017},
date = {2017-05-15},
address = {Lisbon Portugal},
organization = {3rd International Ocean Colour Science meeting},
abstract = {In the Aegean Sea and Eastern Mediterranean there are large discrepancies between in situ and satellite ocean colour derived chlorophyll concentrations. The quantity that is monitored by ocean colour satellites and that can be used in the estimation of chlorophyll concentration is the remote sensing reflectance, defined as the ratio of the water leaving spectral radiance to the downwelling spectral irradiance. It can be determined in the field, with either above or in-water radiance and irradiance measurements. The complex optical properties of the North-East Aegean Sea, including radiance and irradiance, were studied during the AegeanMarTech project. Chlorophyll concentration estimates were derived from simultaneous above and in-water radiometric measurements. These were validated against chlorophyll concentration field data and compared against concurrent MODIS data from which chlorophyll was derived using two simple empirical algorithms. It was found that the MedOC3 algorithm outperforms the operational OC3M-547 algorithm and produces the least bias when compared against HPLC derived in situ chlorophyll. It is concluded that the greatest uncertainty in the inversion arises due to CDOM absorption below the 488 nm band. The reflectance ratios indicated that there is always an excess of yellow matter present in the study area and the water type could not be characterized optically as "typical open ocean" Case 1.},
note = {15-19 Μay },
keywords = {NE Aegean Sea, ocean colour, ocean optics, remote sensing},
pubstate = {published},
tppubtype = {conference}
}
In the Aegean Sea and Eastern Mediterranean there are large discrepancies between in situ and satellite ocean colour derived chlorophyll concentrations. The quantity that is monitored by ocean colour satellites and that can be used in the estimation of chlorophyll concentration is the remote sensing reflectance, defined as the ratio of the water leaving spectral radiance to the downwelling spectral irradiance. It can be determined in the field, with either above or in-water radiance and irradiance measurements. The complex optical properties of the North-East Aegean Sea, including radiance and irradiance, were studied during the AegeanMarTech project. Chlorophyll concentration estimates were derived from simultaneous above and in-water radiometric measurements. These were validated against chlorophyll concentration field data and compared against concurrent MODIS data from which chlorophyll was derived using two simple empirical algorithms. It was found that the MedOC3 algorithm outperforms the operational OC3M-547 algorithm and produces the least bias when compared against HPLC derived in situ chlorophyll. It is concluded that the greatest uncertainty in the inversion arises due to CDOM absorption below the 488 nm band. The reflectance ratios indicated that there is always an excess of yellow matter present in the study area and the water type could not be characterized optically as "typical open ocean" Case 1.
@conference{Karageorgis2015,
title = {Particle distribution and composition in the NE Aegean Sea based on transmissometry, optical backscattering and size measurements},
author = {A.P. Karageorgis and A. Androni and G. Assimakopoulou and A.C. Banks and P. Drakopoulos and G. Kabouri and Th. Kanellopoulos and E. Krasakopoulou and A. Lagaria and M. Morfis and K. Pagou and V. Papadopoulos and K. Parinos and S. Psarra and P. Renieris and N. Spyridakis},
url = {https://www.researchgate.net/publication/306441194_Particle_distribution_and_composition_in_the_NE_Aegean_Sea_based_on_transmissometry_optical_backscattering_and_size_measurements},
isbn = {978-960-9798-08-2},
year = {2015},
date = {2015-05-01},
pages = {777-780},
organization = {Proc. 11th Panhel. Symp. Oceanogr. & Fish},
abstract = {The complex optical properties of NE Aegean Sea particles were studied in the framework of Perseus and AegeanMarTech projects. Inherent optical properties (IOPs; beam attenuation, optical backscattering, fluorescence) and discrete bottle data (PMC, POC, TChl-a) were measured during October 2013. Black Sea water (BSW) enters into the Aegean Sea from the Dardanelles and disperses to the west-northwest, as traced by characteristic salinity minima. The core of the BSW to the east of Limnos Island was relatively particle-enriched, showing maxima in beam c p , b bp , fluorescence, D 50 , PMC, POC, and TChl-a. Organic particles dominated in the upper water column, whereas resuspension of surface sediments was detected.},
keywords = {IOP, NE Aegean Sea, particle size, particulate matter, scattering},
pubstate = {published},
tppubtype = {conference}
}
The complex optical properties of NE Aegean Sea particles were studied in the framework of Perseus and AegeanMarTech projects. Inherent optical properties (IOPs; beam attenuation, optical backscattering, fluorescence) and discrete bottle data (PMC, POC, TChl-a) were measured during October 2013. Black Sea water (BSW) enters into the Aegean Sea from the Dardanelles and disperses to the west-northwest, as traced by characteristic salinity minima. The core of the BSW to the east of Limnos Island was relatively particle-enriched, showing maxima in beam c p , b bp , fluorescence, D 50 , PMC, POC, and TChl-a. Organic particles dominated in the upper water column, whereas resuspension of surface sediments was detected.
@conference{Drakopoulos2015,
title = {Above and in-water remote sensing reflectance measurements during the AegeanMarTech project: A first appraisal},
author = {P.G. Drakopoulos and A.C. Banks and G. Kakagiannis and A.P. Karageorgis and A. Lagaria and A. Papadopoulou and S. Psarra and N. Spyridakis and V. Zervakis},
url = {https://www.researchgate.net/publication/306441341_Above_and_in-water_remote_sensing_reflectance_measurements_during_the_AegeanMarTech_project_A_first_appraisal},
isbn = {978-960-9798-08-2},
year = {2015},
date = {2015-05-01},
pages = {781-784},
organization = {Proc. 11th Panhel. Symp. Oceanogr. & Fish.},
abstract = {The optically complex properties of NE Aegean Sea were studied during the AegeanMarTech project. Simultaneous above and in-water ocean colour measurements were validated with chlorophyll concentration field data and compared against concurrent MODIS images. It was found that the Med-OC3 algorithm outperforms the operational OC3M-547 algorithm and produces the least bias when compared against HPLC derived in situ [Chl]. Satellite derived concentrations tend to underestimate [Chl] by >10% at best, the greatest uncertainty arising due to CDOM absorption below the 488 nm band. Relevant reflectance ratios indicated that there is always an excess of yellow mater present in the study area and the water type could not be characterized optically as " typical open ocean " Case 1. Further investigation is under way.},
keywords = {NE Aegean Sea, ocean color, ocean optics, remote sensing},
pubstate = {published},
tppubtype = {conference}
}
The optically complex properties of NE Aegean Sea were studied during the AegeanMarTech project. Simultaneous above and in-water ocean colour measurements were validated with chlorophyll concentration field data and compared against concurrent MODIS images. It was found that the Med-OC3 algorithm outperforms the operational OC3M-547 algorithm and produces the least bias when compared against HPLC derived in situ [Chl]. Satellite derived concentrations tend to underestimate [Chl] by >10% at best, the greatest uncertainty arising due to CDOM absorption below the 488 nm band. Relevant reflectance ratios indicated that there is always an excess of yellow mater present in the study area and the water type could not be characterized optically as " typical open ocean " Case 1. Further investigation is under way.
