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OCRT 5/5/2009 JRM & MBFluorescence
Beyond Fluorescence Line Beyond Fluorescence Line Height – Making sense of Height – Making sense of chlorophyll fluorescencechlorophyll fluorescence
Ru MorrisonRu Morrison((Ru.Morrison@unh.eduRu.Morrison@unh.edu))
Mike BehrenfeldMike Behrenfeld((behrenfm@science.oregonstate.edubehrenfm@science.oregonstate.edu))
OCRT 5/5/2009 JRM & MBFluorescence
You can’t see a whale from space You can’t see a whale from space but you can see …but you can see …
Seeing inside phytoplankton from Seeing inside phytoplankton from spacespace
OCRT 5/5/2009 JRM & MBFluorescence
OutlineOutline
• What is phytoplankton fluorescence?What is phytoplankton fluorescence?
• The current fluorescence paradoxThe current fluorescence paradox
• Fluorescence variabilityFluorescence variability– Games of chanceGames of chance– Changing the odds – 2003, 2008, 2009Changing the odds – 2003, 2008, 2009
• What fluorescence can doWhat fluorescence can do
• What fluorescence can’t doWhat fluorescence can’t do
• What we need to do!What we need to do!
OCRT 5/5/2009 JRM & MBFluorescence
What is phytoplankton What is phytoplankton fluorescence?fluorescence?
Fluorescence Line Height
Fluorescence Efficiency or Fluorescence Efficiency or quantum yield, quantum yield, φφff
ratio of photons out to inratio of photons out to in ophf Ea
F
OCRT 5/5/2009 JRM & MBFluorescence
The Fluorescence The Fluorescence ParadoxParadox
• Two potential and mutually incompatible Two potential and mutually incompatible usesuses– Abundance - need constant fluorescence Abundance - need constant fluorescence
efficiencyefficiency– Physiology - need variable fluorescence Physiology - need variable fluorescence
efficiency.efficiency.
OCRT 5/5/2009 JRM & MBFluorescence
Fluorescence variability – games of Fluorescence variability – games of chancechance
• Fluorescence comes from PSII Fluorescence comes from PSII (mainly)(mainly)
• ΦΦff = chance getting an absorbed = chance getting an absorbed photon to PSII and then back out photon to PSII and then back out againagain
• Variability comes from quenchingVariability comes from quenching– Photochemical quenching (qP)Photochemical quenching (qP)– Non-photochemical quenchingNon-photochemical quenching
• Antennae quenching (qE)Antennae quenching (qE)
• PSII RC downregulation / damage (qI)PSII RC downregulation / damage (qI)
– Changes in proportion of PSII to total Changes in proportion of PSII to total absorptionabsorption
OCRT 5/5/2009 JRM & MBFluorescence
NPQ Dominates in Satellite Derived measurements
Energy Dependent Quenching – decreases φf with increasing irradiance
PSII downregulation (photoinhibition) – suppresses φf at all irradiances
Changing the odds - 2003Changing the odds - 2003
from Morrison L&O, 2003
PQ NPQ
Scalar Irradiance
Qua
ntum
Yie
ld o
f F
luor
esce
nce
OCRT 5/5/2009 JRM & MBFluorescence
Changing the odds – 2008Changing the odds – 2008
Behrenfeld et al., BGD, 2009
OCRT 5/5/2009 JRM & MBFluorescence
Nutrient stressNutrient stress
Behrenfeld et al., BGD, 2009
But Schallenberg et al. (2008) suggested macronutrient stress increased φf with unbalanced growth conditions
OCRT 5/5/2009 JRM & MBFluorescence
Detection of iron stress effects.Detection of iron stress effects.
Behrenfeld et al., BGD, 2009
OCRT 5/5/2009 JRM & MBFluorescence
PN q
ff
q
EIf AAqq )1(maxmin To EE
E eq /
ko EEeA /
Changing the odds - 2009
OCRT 5/5/2009 JRM & MBFluorescence
Gulf of Maine case Study
Climatologies(2004-2007)
OCRT 5/5/2009 JRM & MBFluorescence
Gulf of Maine case Study
Climatologies(2004-2007)
Dec
Jan
OCRT 5/5/2009 JRM & MBFluorescence
Gulf of Maine case Study
Climatologies(2004-2007)
Dec
Jan
OCRT 5/5/2009 JRM & MBFluorescence
OCRT 5/5/2009 JRM & MBFluorescence
Seasonal Seasonal ClimatologyClimatology
OCRT 5/5/2009 JRM & MBFluorescence
Bas
in S
cale
B
asin
Sca
le
Pat
tern
sP
atte
rns
Goodwin et al., 2009
OCRT 5/5/2009 JRM & MBFluorescence
Timing of stratification onset and Timing of stratification onset and spring bloomspring bloom
OCRT 5/5/2009 JRM & MBFluorescence
What can Fluorescence doWhat can Fluorescence do
• Give insights into phytoplankton Give insights into phytoplankton physiologyphysiology– Iron stressIron stress– Photocompensation / acclimation with growth Photocompensation / acclimation with growth
irradiance that incorporates hydrodynamicsirradiance that incorporates hydrodynamics
OCRT 5/5/2009 JRM & MBFluorescence
What Fluorescence can’t doWhat Fluorescence can’t do
• Abundance apart Abundance apart from geographically from geographically and spatially limited and spatially limited studies.studies.
OCRT 5/5/2009 JRM & MBFluorescence
What do we need to do?What do we need to do?
• Minimize calibration uncertainties in the Minimize calibration uncertainties in the FLH productFLH product
• Develop operational Develop operational φφff product product• Investigate the heck out of it in-light of Investigate the heck out of it in-light of
these recent insights.these recent insights.– With current missionsWith current missions
• How do you separate nutrient and How do you separate nutrient and photoacclimation effects?photoacclimation effects?
– For upcoming missions (GEOCAPE For upcoming missions (GEOCAPE interesting)interesting)