Two decades of continuous oceanic CO2
observations in the North Atlantic Ocean near Bermuda at Hydrostation S
(32°50'N, 64°10'W; 1983-1988) and BATS (Bermuda Atlantic Time-series Study;
32°10'N, 64°30'W; 1988-2003) sites are examined for long-term trends, changes
in the oceanic sink of CO2, and the influence of atmospheric changes
and short-term hurricane wind events. Over the 1983-2003 period, surface DIC
and alkalinity increased at a rate of +1.18 + 0.19 µmoles kg-1 year-1
and +0.69 + 0.14 µmoles kg-1 year-1, respectively. The
observed rate of surface ocean salinity normalized DIC (nDIC) was +0.79 + 0.13
µmoles kg-1 year-1 and similar to that expected from
oceanic equilibration with increasing CO2 in the atmosphere. The
upward trend in oceanic p CO2 (1.53 + 0.13 µatm year-) is also
identical to the rate of atmospheric CO2 increase (1.59 + 0.02 µatm
year-1) over the last 20 years. The ocean near Bermuda
has also become more acidic, with a decrease in seawater pH of 0.0012 + 0.0006
pH units year-1.
Author: N.R. Bates (nick at bbsr dot edu)
Filesize: 15.80 Kb