1. Norm Nelson, Dave Siegel Institute for Computational Earth System Science, UCSB Bermuda Bio-Optics Project Decade-Plus Perspective on Ocean Color

2. Overview Science Goals Data Streams Accomplishments Overview Science Goals Data Streams Accomplishments A Look at the Time Series A Look at the Time Series Bermuda Bio-Optics Project

3. Understand processes controlling underwater light environment in the Sargasso Sea Understand processes controlling underwater light environment in the Sargasso Sea Algorithm development (With Stéphane Maritorena) Algorithm development (With Stéphane Maritorena) Calibration and validation of ocean color sensors Calibration and validation of ocean color sensors Bermuda Bio-Optics Project Overview - Main Science Goals

4. Light, primary productivity, and photosynthetic quantum yield Light, primary productivity, and photosynthetic quantum yield Distribution and dynamics of CDOM (Sargasso Sea and global) Distribution and dynamics of CDOM (Sargasso Sea and global) Photochemistry and DMS cycling Photochemistry and DMS cycling Bermuda Bio-Optics Project Overview - Main Science Achievements

5. Bermuda Bio-Optics Project Overview - Data Streams Time-series co-located with BATS (32N 64W), starting in 1991 Also - f requent regional studies Time-series co-located with BATS (32N 64W), starting in 1991 Also - f requent regional studies Core Measurements: E d, E s, L u (7-14, BSI & Satlantic radiometers ) [chl a] (fluorometric) Since 1994: a p,a d (QFT) a cdom (conventional UV-Vis spectroscopy) Core Measurements: E d, E s, L u (7-14, BSI & Satlantic radiometers ) [chl a] (fluorometric) Since 1994: a p,a d (QFT) a cdom (conventional UV-Vis spectroscopy)

6. Concurrent data from the BATS Project Hydrography Carbon (inorganic, organic) Nutrients Primary Production C and N flux (sediment traps) Phytoplankton pigments (HPLC) Concurrent data from the BATS Project Hydrography Carbon (inorganic, organic) Nutrients Primary Production C and N flux (sediment traps) Phytoplankton pigments (HPLC) Other BBOP data (not full time-series) AC-9 absorption coefficient profiles L w (0+), ASD FieldSpec radiometer L sun, Microtops sunphotometer Other BBOP data (not full time-series) AC-9 absorption coefficient profiles L w (0+), ASD FieldSpec radiometer L sun, Microtops sunphotometer Bermuda Bio-Optics Project Overview - Data Streams

7. Radiometer calibration: in house, using NIST-traceable standards, participated in SeaWiFS and SIMBIOS intercomparisons: Same engineer for entire project (Dave Menzies) Radiometer calibration: in house, using NIST-traceable standards, participated in SeaWiFS and SIMBIOS intercomparisons: Same engineer for entire project (Dave Menzies) Bermuda Bio-Optics Project Overview - Data Streams

8. Bermuda Bio-Optics Project Radiometry – 14 year time series 441 nm (MER) 443 nm (SPMR)

9. Absorption Coefficient Components CDOM Phytoplankton Detritus Phytoplankton absorption ratios (440/674nm) Absorption Coefficient Components CDOM Phytoplankton Detritus Phytoplankton absorption ratios (440/674nm) Are there interannual or longer term trends in addition to already-documented seasonal patterns? Are there interannual or longer term trends in addition to already-documented seasonal patterns? Bermuda Bio-Optics Project Absorption Coefficient – 10 Year Time Series

10. STMW BATS CDOM Profile STMW (18° Water) Surface Bleached Layer Main Thermocline

17. CDOM exhibits seasonal and interannual variability CDOM exhibits seasonal and interannual variability Possible teleconnection to climate oscillators (NAO shown) Possible teleconnection to climate oscillators (NAO shown)

18. Control of CDOM at BATS Annual: Balance between local production and solar bleaching Annual: Balance between local production and solar bleaching Interannual: Multi-year accumulation at depth and ‘resetting’ by deeper winter mixing (similar to DOC patterns) Interannual: Multi-year accumulation at depth and ‘resetting’ by deeper winter mixing (similar to DOC patterns)

19. Absorption by Phytoplankton Phytoplankton pigments dominate absorption (detrital contribution small, correlated with phytoplankton) Phytoplankton pigments dominate absorption (detrital contribution small, correlated with phytoplankton) Strong seasonal cycle related to spring bloom Strong seasonal cycle related to spring bloom Seasonal change in absorption properties related to photoadaptation and seasonal succession of phytoplankton species Seasonal change in absorption properties related to photoadaptation and seasonal succession of phytoplankton species Primary production variability has been linked to climate oscillators such as ENSO Primary production variability has been linked to climate oscillators such as ENSO

20. Particle Absorption

24. Trends in Absorbing Components at BATS CDOM abundance governed in part by physical processes possibly teleconnected to climate oscillators CDOM abundance governed in part by physical processes possibly teleconnected to climate oscillators Phytoplankton abundance and species succession has not varied along the same time scales Phytoplankton abundance and species succession has not varied along the same time scales

25. Conclusions (so far) The BBOP time series is enabling us to observe and diagnose ocean color variations occurring on climate-oscillator time scales. The BBOP time series is enabling us to observe and diagnose ocean color variations occurring on climate-oscillator time scales. CDOM abundance apparently responds on these time scales CDOM abundance apparently responds on these time scales So far we are not seeing this in a dramatic way with the phytoplankton community So far we are not seeing this in a dramatic way with the phytoplankton community

26. Acknowledgments Ocean Biology and Biogeochemistry Program, NASA Ocean Biology and Biogeochemistry Program, NASA Collaborators I’ve not mentioned (there are many, thank you) Collaborators I’ve not mentioned (there are many, thank you) BBOP and BATS Project technicians, engineers, and students over the years (I could fill several slides) BBOP and BATS Project technicians, engineers, and students over the years (I could fill several slides)