Pierre Jaccard 1

Chl-a Fluorescence Measurements

10.06.2013 - MyOcean Tutorial, NERSC, Bergen

Pierre Jaccard 210.06.2013 - MyOcean Tutorial, NERSC, Bergen

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

K. Sørensen, M. Norli and A. Folkestad

3

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– ...

Pierre Jaccard 4

Measurements In Practice

10.06.2013 - MyOcean Tutorial, NERSC, Bergen

HPLC(SPECTRO)

COEFFS

HPLC(SPECTRO)

Chl-a FluorescenceFluorometerChl-a

in situ

in vitro

COEFFSDelayed modeFluorometerChl-a

5

Fluorescence high at small concentrations

Fluorescence low at high concentrations

Ferrybox Chl_a time-series 2002-2008

No yearly calibration of the fluorescence

Better match at high concentrations

With yearly calibration of the fluorescence

K. Sørensen, M. Norli and A. Folkestad

6

• Most months show the same trend:• High ratio at night• Lower ratio at daytime

FerryBox seasonal and night and day variation

Yearly calibration of the Chl-a fluorescense using all the Chl-a_hplc water samples

K. Sørensen, M. Norli and A. Folkestad

7

Variation of Chl-a_Fl/Chl-a for algal culture

1 2 3 4 5 6 7 8 9

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Nr. Algekulturer1 Chrysochromulina polylepis2 Dunaliella tertiolecta3 Emiliania huxleyi4 Oscilatoria agardii5 Prorocentrum minimum6 Prymnesium parvum7 Phaeodactylum tricornutum8 Selenastrum capricornutum9 Skeletonema costatum

Algal culture

Chl-

a_F

l/C

hl-

a

Determined during dark adapted algal from a exponetial growing algal culture

Factor 6 all species tested

Factor 2.5- 3 for Norw. waters

K. Sørensen, M. Norli and A. Folkestad

8

Validation of the chlorophyll-a fluorescence with monitoring data

K. Sørensen, M. Norli and A. Folkestad