Publication Date:
2022-05-26
Description:
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): C07S06, doi:10.1029/2005JC003173.
Description:
Climate variability drives significant changes in the physical
state of the North Pacific, and thus there may be important impacts of climate
variability on the upper ocean carbon balance across the basin. We address
this issue by considering the response of seven biogeochemical ocean
models to climate variability in the North Pacific. The models’ upper ocean
pCO2 and air-sea CO2 flux respond similarly to climate variability on seasonal
to decadal timescales. Modeled seasonal cycles of pCO2 and its temperature
and non-temperature driven components at three contrasting oceanographic
sites capture the basic features found in observations [Takahashi et al.,
2002, 2006; Keeling et al., 2004; Brix et al., 2004]. However, particularly in
the Western Subarctic Gyre, the models have difficulty representing the temporal
structure of the total pCO2 cycle because it results from the difference
of these two large and opposing components. In all but one model, the airsea
CO2 flux interannual variability (1σ) in the North Pacific is smaller (ranges
across models from 0.03 to 0.11 PgC/yr) than in the Tropical Pacific (ranges
across models from 0.08 to 0.19 PgC/yr), and the timeseries of the first or
second EOF of the air-sea CO2 flux has a significant correlation with the Pacific
Decadal Oscillation (PDO). Though air-sea CO2 flux anomalies are correlated
with the PDO, their magnitudes are small (up to ±0.025 PgC/yr (1σ)). Flux anomalies are damped because anomalies in the key drivers of pCO2
(temperature, dissolved inorganic carbon (DIC) and alkalinity) are all of similar
magnitude and have strongly opposing effects that damp total pCO2 anomalies.
Description:
F. Chai and L. Shi acknowledge grant support from NSF (OCE 0137272) and NASA (NAG5-9348; S. Doney and I. Lima from NSF/ONR NOPP (N000140210370) and NASA (NNG05GG30G); G. McKinley from NASA (NNG05GF94G); and T. Takahashi from
NOAA (NA16GP2001).
Keywords:
Ocean carbon cycle
;
Ocean models
;
PDO
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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