Atlantic Adjustments

This page summarizes the various lines of evidence to suggest adjustment of parameters. Full discussion is provided in the CDIAC report ORNL/CDIAC-140 "Comparison of inorganic carbon system parameters measured in the Atlantic Ocean from 1990 to 1998" by Wanninkhof et al. (2003) (click here for pdf version of report). The recommended adjustments are based on all available evidence, including crossover results, internal consistency checks, regional multi linear regressions, data from overlapping cruises and calibration information. Based on the overall precision of the measurements on the cruises, we recommend adjustments only if there is clear and consistent evidence for biases greater than 4 μmol/kg for TCO₂ and 6 μmol/kg for TALK.

In the course of the investigation we determined that data from several cruises were not suitable for further analysis because of significant scatter in data. These data are not used in the synthesis. The proposed adjustments are recommendations and have been applied only to the GLODAP Atlantic synthesis files at /oceans/glodap/data_files.html, not the original files stored at the CDIAC and other national data facilities. The summary of the adjustments for the Atlantic dataset is given below.

Cruises checked are presented in the Atlantic Ocean carbon measurement summary .

The following parameters are omitted from the synthesis:

A06 : TCO₂ & TALK
A07: TCO₂ & TALK
A1E: TALK
A23: TCO₂

Adjustments

TCO₂
No adjustments are recommended for TCO₂. TCO₂ data from cruises are believed to be consistent to 4 μmol/kg.

TALK
It is recommended that all TALK data from A01W are adjusted upward by 14 μmol/kg and that 7 μmol/kg is subtracted from TALK data from A09.

All other TALK data are believed to be consistent to 6 μmol/kg.