Premium
Consistency of TTO‐NAS inorganic carbon data with modern measurements
Author(s) -
Tanhua Toste,
Wallace Douglas W. R.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2005gl023248
Subject(s) - alkalinity , dissolved organic carbon , environmental science , environmental chemistry , chemistry , mineralogy , hydrology (agriculture) , geology , organic chemistry , geotechnical engineering
We compare alkalinity and total dissolved inorganic carbon (DIC) measurements made during the Transient Tracers in the Ocean, North Atlantic Study (TTO‐NAS) in 1981 with modern measurements from a TTO reoccupation cruise in 2004 (M60/5). We find that the TTO‐NAS alkalinity values are 3.6 ± 2.3 μmol kg −1 higher than modern alkalinity data tied to Certified Reference Materials. The TTO‐NAS DIC values re‐calculated from original alkalinity and discrete‐pCO 2 data using currently accepted constants are 3.8 μmol kg −1 higher than those reported in the revised TTO data set. This difference is reduced to 0.7 μmol kg −1 when our suggested correction to the TTO‐NAS alkalinity is applied. These re‐calculated DIC values are 2.4 μmol kg −1 too low relative to contemporaneous measurements made by the vacuum extraction/manometric Certified method. Application of this correction brings the TTO data into almost perfect agreement with modern measurements for slowly‐ventilated deep water of the eastern Atlantic.