The terrestrial biosphere is responsible for most of the interannual variability in measurements of atmospheric carbon dioxide through the interactions between fire, growth and soil respiration. The annual processes of growth in the spring and summer followed by decay in the autumn and winter provide the backdrop upon which the climatic modes of variability such as ENSO and the Annular Modes lead to measurable changes in the short-term increase of carbon dioxide in the atmosphere.
In previously published work, we documented the link between the drawdown of carbon dioxide by Northern Hemisphere terrestrial vegetation and the position of the westerly winds in the winter. As an extension of that study, we are using a dynamic vegetation model (LM3V; Shevliakova, 2006) coupled in the GFDL global climate model, to project the impact of potential future changes in the position of the Westerlies on Northern Hemisphere vegetation and atmospheric carbon dioxide. We are working in collaboration with colleagues like Elena Shevliakova at Princeton University to quantitatively examine and project the interplay between vegetation, fire, land-use and climate variability in the GFDL global climate model.