The Indian Ocean Database Synthesis
The Indian Ocean database consists primarily of all the U.S. WOCE and NOAA cruises. Carbon measurements were made as part of the JGOFS Global Survey funded through DOE. Details of the WOCE/JGOFS Indian Ocean CO2 measurement program—including personnel, sampling and measurement protocols, and data quality assurance/quality control checks—are provided in Johnson et al. 1998, Millero et al. 1998, and Johnson et al. 2002 (ORNL/CDIAC-138, NDP-080).
We have also included the data from the French INDIGO and CIVA1 cruises (contributed by A. Poisson). A summary of the combined data set can be found in Sabine et al. 1999. Table 2 is the individual Indian Ocean cruise and personnel summary.
The WOCE/DOE and CIVA TCO2 data have an estimated accuracy of ±2 µmol/kg. Proposed adjustments for the INDIGO I, II, and III TCO2 data to bring them in line with the WOCE/DOE data are +10.7, -9.4, and +6.4 µmol/kg, respectively. The WOCE/DOE and CIVA alkalinity data have an estimated accuracy of ±3 µmol/kg. Proposed adjustments for the INDIGO I and II alkalinity data to bring them in line with the WOCE/DOE data are +6.5 and +6.8 µmol/kg, respectively. These results have been published in Sabine et al. 1999. As part of this work we also evaluated the quality of GEOSECS carbon data. Our study indicates that the GEOSECS TCO2 values are 22.6 µmol/kg high relative to the WOCE/DOE data in the deep Indian Ocean. No adjustmen was proposed for the GEOSECS alkalinity data. Detailed information on the Indian Ocean correction factors given in Table 3.
Johnson, K.M., A.G. Dickson, G. Eischeid, C. Goyet, P. Guenther, R.M. Key, F.J. Millero, D. Purkerson, C.L. Sabine, R.G. Schottle, D.R.W. Wallace, R.J. Wilke and C.D. Winn, Coulometric total carbon dioxide analysis for marine studies: Assessment of the quality of total inorganic carbon measurements made during the US Indian Ocean CO2 Survey 1994-1996, Marine Chemistry, 63, 21-37, 1998.
Millero, F.J., A.G. Dickson, G. Eischeid, C. Goyet, P. Guenther, K.M. Johnson, K. Lee, D. Purkerson, C.L. Sabine, R.M. Key, R.G. Schottle, D.R.W. Wallace, R.J. Wilke and C.D. Winn, Total alkalinity measurements in the Indian Ocean during the WOCE Hydrographic Program CO2 survey cruises 1994-1996, Marine Chemistry, 63, 9-20, 1998.
Sabine, C.L., R.M. Key, K.M. Johnson, F.J. Millero, A. Poisson, J.L. Sarmiento, D.W.R. Wallace and C.D. Winn, Anthropogenic CO2 inventory of the Indian Ocean, Global Biogeochemical Cycles, 13, 179-198, 1999.
- Table 1 gives details about the Indian Ocean Cruise Summary.
- Table 2 gives detailed information about Indian Ocean Cruise personnel.
- Table 3 gives detailed information about Indian Ocean Correction Factors
- As a check on the internal consistency and accuracy of the data we have examined the values in areas where two cruises intersect
- We have provided a summary of the crossover results along with a list of recommended adjustments for an internally consistent database.