OCRT 5/5/2009JRM & MBFluorescence Beyond Fluorescence Line Height – Making sense of chlorophyll fluorescence Ru Morrison ([email protected]) [email protected]

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(([email protected]@unh.edu))

Mike BehrenfeldMike Behrenfeld(([email protected]@science.oregonstate.edu))


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


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!


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


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.


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


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


Changing the odds – 2008Changing the odds – 2008

Behrenfeld et al., BGD, 2009


Nutrient stressNutrient stress


But Schallenberg et al. (2008) suggested macronutrient stress increased φf with unbalanced growth conditions


Detection of iron stress effects.Detection of iron stress effects.



PN q

ff

q

EIf AAqq )1(maxmin To EE

E eq /

ko EEeA /

Changing the odds - 2009


Gulf of Maine case Study

Climatologies(2004-2007)




Dec

Jan




Dec

Jan



Seasonal Seasonal ClimatologyClimatology


Bas

in S

cale

B

asin

Sca

le

Pat

tern

sP

atte

rns

Goodwin et al., 2009


Timing of stratification onset and Timing of stratification onset and spring bloomspring bloom


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


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.


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)

Documents

OCRT 5/5/2009JRM & MBFluorescence Beyond Fluorescence Line Height – Making sense of chlorophyll fluorescence Ru Morrison ([email protected]) [email protected]