1. Response of Ocean Ecosystems to Climate Warming Temperature P b max 3 Models: B&F (1997) Carr (2002) Marra (2003) Primary Production = f (biomass, light, physiology)

2. Measured Integral Primary Production (mgC m -2 h -1 ) Modeled IPP (mgC m -2 h -1 ) constant P b opt measured P b opt r 2 = 0.38r 2 = 0.86 Product Yields

3. Terrestrial Systems: The CASA model Temperature?? Ocean?

4. P b max = net carbon fixing capacity light harvesting capacity TemperatureEnzyme Activity & Concentration No direct effect on P b max Growth RateEqual changes in carbon fixation & light harvesting No direct effect on P b max ?

6. Relative Chlorophyll Concentration Growth Irradiance (  mol quanta / m 2 / s) E k -dependent variability Nutrient ‘Charged’Nutrient ‘Depleted’ Growth Irradiance (umol quanta m -2 s -1 ) Chlorophyll ( ) Calvin Cycle Capacity ( ) & Pbmax ( ) : < MLD > MLD

7. Optical Mixing Depth Relative Chlorophyll Relative Subsurface Light Photoacclimation 300  Ein 30  Ein equal concentration Photoacclimation – average or median? Average Mixed Layer Light Median Mixed Layer Light

8. Nutricline & Thermocline Depth (m) Latitude NorthSouthNorthSouth AMT-2AMT-3 Chlorophyll-a Concentration (mg/m 3 ).01155010.02.05.1.2.5 Atlantic Meridional Transect Latitude Measured & Modeled Mixed Layer P b max

9. Measured & Modeled P b max Progressive Days BATS 6-year Time Series

10. Model light-saturated photosynthesis Measured light-saturated photosynthesis -- requires MLD --

11. E k -independent variability Light Chlorophyll-specific photosynthesis Field Data

12. Stroma Lumen PSI Cyt b 6 f ATPase aa 3 -type Cyt. Oxid. PTOX c 553 H20H20 O2O2 1212 PQ PQH 2 Ndh PSII e + e e e e ATPADP + P i Fdx H202H202 H20H20 Cell Metabolism NADPH O 2 H20H20 1212 H20H20 1212 A B Chloroplast Amino Acid Biosynthesis GAP Storage Rubisco CO 2 Calvin- Bensen Cycle GAPRuBP NO 3 - GOGAT GS gln NO 2 - NH 4 + e e OAA Malate OAA Malate OAA Malate GAP PEP NADP + NADH NAD + Cytosol     ETCETC H20H20 O 2 1212 e ATP ADP + P i    OAA citrate Citric Acid Cycle NADH NAD + Mitochondria NADH glu e e e e PGA BPGA GAP/DHAP PGA BPGA GAP/DHAP NADH NAD + e e 2 H H NADPH

13. Photosystem II Photosystem I Sum = Remote Sensing Chlorophyll Nitrogen Reduction & Amino Acid Biosynthesis Medium Pathway 3-C product to Citric Acid Cycle & Mitochondria Fast Pathway to Mitochondria to generate ATP Calvin Cycle Carbon Fixation Carbon Storage O2O2 Carbon Growth

14. Tropical Pacific Data – 16 o S to 1 o N

15. Light Growth Rate (+nutrients) (+light) Growth Irradiance Relative Growth Rate Chlorophyll : Carbon Note: Chl:C ranges from 0.1 In a single species, light & nutrients can cause C:Chl to vary from 800

16. Temperature P b max Light limitation dominates Light-Nutrient interactions Light versus Nutrient as dominant control BOTTOM LINE: Temperature not a good model for current production & worse for future. Best approach is direct attack on light and growth rate

17. cpcp POC J. Bishop 1999 Deep Sea Research BATS HOT NABE cp*cp* 14 C-based photosynthetic efficiency

18. B C D E F Year Chlorophyll concentration ( ), b bp ( ) Satellite Chl:C Ratio ( ) 75 o 0 o 15 o 30 o 90 o 60 o 45 o 60 o 75 o 90 o 15 o 30 o 45 o 75 o 0 o 15 o 30 o 90 o 60 o 45 o 60 o 75 o 90 o 15 o 30 o 45 o NP SP SA NA NP SP CP CA SA NA SI NI CA B C D E F

19. b bp -based Chl:C = a + b exp -3  Ig Interaction Growth rateLight

20. Current Limitation… 0.0005 0.001 0.01 0.05 0.010.1110 Inversion b bp 0.0010.010.1110 0.001 0.01 0.1 1 10 SeaWiFS chlorophyll Inversion chlorophyll

21. The P hysiology L idar- M ultispectral Mission Exploring complex ecosystems of our global oceans