Relative Fluorescence

2. PSII Fm Fv Fo FRR DATA Relative Fluorescence Flashlet Number

3. Relative Fluorescence Flashlet Number

4. Relative Fluorescence Flashlet Number Relative Fluorescence Time (s)

5. >140,000 Variable fluorescence (FRRf) Incident PAR Chlorophyll & HPLC beam attenuation @ 660 nm Macronutrients spectral attenuation & absorption (AC9) Fe concentrations cDOM Photosynthesis-Irradiance (14C) particulate backscattering coefficients Phytoplankton absorption web.science.oregonstate.edu/ocean.productivity/ 26 short-term (18-30 h) enrichment experiments (control, +NO3, +NH4, +PO4, +Fe) Depth-resolved time-series stations Tropical Pacific Study 35o 35o 8 2001A 25o 25o Hawaii 2006 2005 6 15o 15o 2000 2003 2001B 4 Nitrate Concentrations (M) 5o 2001D ‘GasEx’ 2002 5o 1994 ‘OliPac’ 5o 5o 2 2001C 1995 IronExII 15o 15o 0 25o 25o 120o E 140o E 160o E 180o 160o W 140o W 120o W 100o W 80o W

6. 2005 2006A PAR (uEin) Fo & Fm (relative) 2006B 2007 Sequence Number

7. 2005 2006A PAR (uEin) Fv/Fm (relative) 2006B 2007 Sequence Number

8. 2005 2006A PAR (uEin) Sigma PSII (relative) 2006B 2007 Sequence Number

9. Fluorescence properties in the tropical Pacific: 35o 20 Hawaii 25o 15o PQ turnover time 5o 10 5o 15o 0 25o 12:00 0:00 12:00 0:00 12:00 120o E 140o E 160o E 180o 160o W 140o W 120o W 100o W 80o W Time Low nitrate, low biomass zone High nitrate, high biomass zone 25 Slow PQ turnover 20 15 PQ pool electron turnover time 10 Rapid PQ turnover 5 0 160 120 90 80 60 40 20 00 20 40 80 S N 140 Latitude

10. FRRf • Photosynthesis OFF, Respiration ON • Increasing PQ pool reduction • and electron backtransfer • Photosynthate supply running out • PSI & PSII turnover at dawn 1 2 0.3 O2 H20 0.2 PQ Fv/Fm PQH2 0.1 Large nocturnal decreases require Fe stress, modest or better growth rates, but not high macronutrients A Nocturnal Decreases PQ 12:00 0:00 12:00 0:00 12:00 Iron stress PQH2 Time NADH Ndh Nighttime e e e e e The nocturnal decrease: Fdx Cyt b6 f Terminal oxidase PSII PSI  c553 Slight electron backtransfer MAJOR electron backtransfer

11. 14-C data Blue = day, sunrise, sunset Pink = night

12. FRRf Low dawn maxima require Fe stress, high macronutrients, but not rapid growth rates PQ PQH2 2 H Iron stress Iron stress e e e 1 2 Dawn maxima: High Dawn Maxima 0.5 0.4 Low Dawn Maxima Fv/Fm 0.3 0.2 0.1 160 120 100 80 60 40 20 00 20 40 80 S N 140 Latitude fluorescence Fdx Cyt b6 f Isi PSII PSI c553 O2 + H20

13. Large state transitions require Fe stress, significant prokaryotic biomass, but not high macronutrients Nocturnal PSII cross-section decreases: 400 300 PSII (2photon-1) 200 100 0 160 120 100 80 60 40 20 00 20 40 80 S 140 N Latitude ‘State transitions’

14. Long PQ turnover times require Fe stress-induced decreases in down-stream components PQ turnover:

15. 35o N 35o N 35o N 25o N 25o N 25o N 15o N 15o N 15o N Latitude Latitude Latitude 5o N 5o N 5o N 5o S 5o S 5o S 15o S 15o S 15o S 25o S 25o S 25o S 0.6 0.4 Dawn Fv /Fm maximum 0.2 0 175o W 155o W 115o W 95o W 165o E 135o W 60% 40% Nocturnal decrease in Fv /Fm 20% 0% 175o W 155o W 115o W 95o W 165o E 135o W I I II III I I 175o W 155o W 115o W 95o W 165o E 135o W Longitude

16. POC / PON 2006A Blanks Sequential Station

17. 2005 2006A PON (ug L-1) 2006B Sequence Number

18. 2005 2006A POC (ug L-1) 2006B Sequence Number

19. 2005 2006A C:N ratio 2006B Sequence Number

20. Turner fluorometer

21. 2005 2006A 2006B 2007 Sequence Number