North Atlantic Carbon Cycle Response to Climate Variability in the Subtropics

Conference Proceedings Paper
North Atlantic Carbon Cycle Response to Climate Variability in the Subtropics
Ullman, D. G.A. McKinley, V. Bennington, & S. Dutkiewicz (2008)
Conference Proceedings, AGU/ASLO Ocean Sciences Meeting

Abstract/Summary:

Air-sea CO2 flux variability in the North Atlantic has been found to be small in a variety of ocean biogeochemical models and at least one atmospheric CO2 inversion study (McKinley et al. 2004), yet the mechanisms that damp variability in this region of large net carbon uptake are poorly understood. A biogeochemical general circulation model was used to assess the impact of climate variability from 1980-2006 on the CO2 flux and surface pCO2 in the North Atlantic. Results show a strong correlation between flux and pCO2 variability. Model output pCO2 was separated into its influences from dissolved inorganic carbon (DIC), alkalinity (Alk), phosphate, silicate, sea-surface temperature (SST), and sea-surface salinity (SSS) to assess the mechanisms driving pCO2 variability. These pCO2 components were regressed onto the North Atlantic Oscillation (NAO) index, the main mode of climate variability in the region. The effects of SST and Alk on pCO2 variability balance each other in the eastern subtropical gyre, such that the overall variability of pCO2 is small. Driving forces behind Alk/SST variability in the eastern subtropics are evaluated in the context of ESTOC observations.

Citation:

Ullman, D. G.A. McKinley, V. Bennington, & S. Dutkiewicz (2008): North Atlantic Carbon Cycle Response to Climate Variability in the Subtropics. Conference Proceedings, AGU/ASLO Ocean Sciences Meeting (http://www.aslo.org/orlando2008/index.html)
  • Conference Proceedings Paper
North Atlantic Carbon Cycle Response to Climate Variability in the Subtropics

Ullman, D. G.A. McKinley, V. Bennington, & S. Dutkiewicz

AGU/ASLO Ocean Sciences Meeting

Abstract/Summary: 

Air-sea CO2 flux variability in the North Atlantic has been found to be small in a variety of ocean biogeochemical models and at least one atmospheric CO2 inversion study (McKinley et al. 2004), yet the mechanisms that damp variability in this region of large net carbon uptake are poorly understood. A biogeochemical general circulation model was used to assess the impact of climate variability from 1980-2006 on the CO2 flux and surface pCO2 in the North Atlantic. Results show a strong correlation between flux and pCO2 variability. Model output pCO2 was separated into its influences from dissolved inorganic carbon (DIC), alkalinity (Alk), phosphate, silicate, sea-surface temperature (SST), and sea-surface salinity (SSS) to assess the mechanisms driving pCO2 variability. These pCO2 components were regressed onto the North Atlantic Oscillation (NAO) index, the main mode of climate variability in the region. The effects of SST and Alk on pCO2 variability balance each other in the eastern subtropical gyre, such that the overall variability of pCO2 is small. Driving forces behind Alk/SST variability in the eastern subtropics are evaluated in the context of ESTOC observations.