Open AccessAnthropogenic increase of oceanic p CO 2 in the Barents Sea surface water
Author(s) -
Omar Abdirahman,
Johannessen Truls,
Kaltin Staffan,
Olsen Are
Publication year - 2003
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2002jc001628
Subject(s) - alkalinity , salinity , atmosphere (unit) , surface water , environmental science , seawater , mole fraction , oxygen , atmospheric sciences , chemistry , oceanography , geology , meteorology , physics , organic chemistry , environmental engineering
We evaluate the change of surface water CO 2 partial pressure ( p CO 2 sw ) in the Barents Sea (BS) between 1967 and 2000–2001. We use temperature (T) data collected during a survey in the BS in 1967 and a relationship between surface water CO 2 mole fraction and T identified by Kelley [1970] to estimate the 1967 p CO 2 sw . On the basis of data of total inorganic carbon, alkalinity, T, and salinity (S) collected during two recent surveys in the BS, we compute p CO 2 sw of 2000–2001. In order to be able to account for natural variations of p CO 2 sw we develop an empirical predictive equation for p CO 2 sw through multivariable linear regression with the 2000–2001 data of T, S, and apparent oxygen utilization (AOU). This relationship is applied to the 1967 T, S, and AOU data, and the output is compared to the 1967 estimates of p CO 2 sw . The difference is ascribed to net uptake of excess CO 2 . The computations show a p CO 2 sw increase of 42 ± 31 μatm between 1967 and 2000–2001, which is due to uptake of excess CO 2 . The p CO 2 increase was uniformly distributed in the BS, suggesting that the uptake of the excess carbon from the atmosphere took place outside the BS rather than across the sea‐air interface within the BS. Moreover, the computed increase was comparable to the increase in atmospheric p CO 2 (∼47 μatm), and thus the p CO 2 gradient across the sea‐air interface has remained nearly unchanged relative to 1967.