1. Global POC Synthesis from Beam Attenuation Data collected during JGOFS, WOCE and other programs A.V. Mishonov, W.D. Gardner, & M.J. Richardson Department of Oceanography Texas A & M University College Station

2. SMP meeting, WH-20002 Background One of the major goals of JGOFS is to develop regional and global mass balances for carbon. Selected areas were studied through shipboard sampling during JGOFS in the last 15 years. To extend global coverage, the marine carbon dioxide survey was integrated with WOCE.

3. SMP meeting, WH-20003 Introduction To obtain information about POC distribution it is possible to use in-situ optical instruments - e.g. transmissometer and convert beam attenuation to POC. In order to extend our data coverage to a global level, we convinced many WOCE scientists to interface our transmissometers on their WOCE cruises during the last decade. We now have an opportunity to reduce & synthesize the data collected.

4. SMP meeting, WH-20004 Objectives 2 Reduce and quality control the transmissometer data from 17 WOCE cruises, providing accessibility and compatibility with JGOFS data for input to models of carbon cycling, aggregation / disaggregation, etc. 2 Establish new ocean- or region-specific algorithms to estimate global POC standing stock in the surface ocean from satellite back-scatter data and our transmissometer data sets. 2 Explore whether the relationship between CO 2 drawdown and POC concentration can be used to estimate POC export from surface waters.

5. SMP meeting, WH-20005 Data Set Transmissometer data have been collected using instruments provided by our group over the last decade in collaboration with WOCE, JGOFS, and other large-scale hydrographic programs. These data include basin-wide transects in the North and South Atlantic, North and South Pacific, Indian, and Southern Oceans. We have been funded to analyze these data and convert the beam attenuation values to POC using the Beam Attenuation:POC relationships derived by our group during JGOFS Process studies.

6. SMP meeting, WH-20006 Station Coverage: WOCE, JGOFS & others JGOFSWOCEOthers

7. SMP meeting, WH-20007 Available Transmissometer Data: 2 19 WOCE cruises (Jan.1990 - Jun.1997), which includes: 2 2231/2239 Sts/Casts; 2 More data will be included from: 2 JGOFS: 22 cruises, 410/1568 Sts/Casts 2 SAVE, WBEX, MCTT, etc: 9 cruises, 600 Sts (est.) 2 Possible future additions: 2 BATS & HOT: TBA 2 other archives (BOFS, NIOP, etc.): TBA

8. SMP meeting, WH-20008 Global Transmissometer Data Stations per Year Distribution

9. SMP meeting, WH-20009 Global Transmissometer Data Stations per Month Distribution

10. SMP meeting, WH-200010 WOCE Cruises (19)

11. SMP meeting, WH-200011 WOCE Stations WOCE Lines Stations

12. SMP meeting, WH-200012 JGOFS Cruises (22)

13. SMP meeting, WH-200013 JGOFS Stations JGOFS Cruises Stations

14. SMP meeting, WH-200014 Other Cruises (9)

15. SMP meeting, WH-200015 Other Stations Other Programs Stations

16. SMP meeting, WH-200016 Data Inventory Sample Sections

17. SMP meeting, WH-200017 Pacific Ocean Section RV Th.Thompson, Jul-Aug. 93, Line p14n Beam Attenuation Distance, nm Depth, m North

18. SMP meeting, WH-200018 Indian Ocean Section RV Knorr, Feb. 95, Line i09s

19. SMP meeting, WH-200019 Future steps 1 Transmissometer database: Transmissometer database: 2 Process 19 WOCE cruises of transmissometer data; 2 Add processed transmissometer & POC data from 22 JGOFS cruises; 2 Add processed transmissometer data from other basin-scale cruises where we have data (9 + ).

20. SMP meeting, WH-200020 Future steps 2 Beam attenuation / POC relationship: Beam attenuation / POC relationship: 2 Use algorithms developed during JGOFS: NABE, Arabian Sea, and Ross Sea/Antarctic Polar Front Zone expeditions; 2 convert Beam Attenuation to POC & quantify spatial and temporal distribution.

21. SMP meeting, WH-200021 JGOFS: Beam C p versus POC POC,  M C/L C p, m -1 NABE: y=0.0376x - 0.0032 R 2 =0.913 APFZ: y=0.0264x - 0.0649 R 2 =0.982 RS: y=0.0178x - 0.0155 R 2 =0.874

22. SMP meeting, WH-200022 Thank You!

23. SMP meeting, WH-200023 Comments: Alexey Mishonov: avm@ocean.tamu.edu Wilford Gardner: wdg@ocean.tamu.edu Mary Jo Richardson:mrichardson@ocean.tamu.edu

24. SMP meeting, WH-200024 Dept. of Oceanography Texas A&M University College Station, TX 77843-3146