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Chl -a Fluorescence Measurements. Differences from Physical Sensors. Living species Measurement principle differs Chl -a Fluoresence is not Chl -a Proxy Neither really bad or good Rather better or worse Correct values from HPLC. Fluctuations in CHLA FL / CHLA CONC.
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Chl-a FluorescenceMeasurements Pierre Jaccard
Differences from Physical Sensors • Livingspecies • Measurementprinciplediffers • Chl-a Fluoresence is not Chl-a • Proxy • Neitherreally bad or good • Ratherbetter or worse • Correctvalues from HPLC Pierre Jaccard
Fluctuations in CHLAFL /CHLACONC • Problem for using Chla_fl as phytoplankton biomass estimation • Search for “solutions” in Ferrybox data series and other dataset/time-series from other investigations using data on: • Sun light • Day length • Temperature • Species composition • ... K. Sørensen, M. Norli and A. Folkestad
Measurements In Practice Pierre Jaccard
FerryboxChl_a time-series 2002-2008 Fluorescence high at small concentrations Fluorescence low at high concentrations Better match at high concentrations No yearly calibration of the fluorescence With yearly calibration of the fluorescence K. Sørensen, M. Norli and A. Folkestad
FerryBox seasonal and night and day variation Most months show the same trend: High ratio at night Lower ratio at daytime Yearly calibration of the Chl-a fluorescense using all the Chl-a_hplc water samples K. Sørensen, M. Norli and A. Folkestad
VariationofChl-a_Fl/Chl-a for algalculture Determined during darkadaptedalgal from a exponetialgrowingalgalculture Factor 2.5- 3 for Norw. waters Chl-a_Fl/Chl-a Factor 6 all species tested Algalculture K. Sørensen, M. Norli and A. Folkestad
Validation of the chlorophyll-a fluorescence with monitoring data K. Sørensen, M. Norli and A. Folkestad