Extended Data Figure 4: Latitude dependence of the seasonal amplitude of FTA.
From: Agricultural Green Revolution as a driver of increasing atmospheric CO2 seasonal amplitude
Fluxes are summed over latitude bands for the VEGAS model and from two atmospheric CO2 inversions: Jena99 and the CarbonTracker. The Northern Hemisphere mid-to-high-latitude region, driven by the winter–summer temperature contrast, is the main contributor. The Southern Hemisphere has the opposite phase to that of the Northern Hemisphere, but its contribution to the global total is small owing to its small land area. The two subtropical maxima around 10° N and 10° S are due to the wet–dry seasonal shift in the Inter-Tropical Convergence Zone (ITCZ) and monsoon movement; these are out of phase and largely cancel each other out in terms of their net contribution to the global total FTA seasonal amplitude. The results are resampled into 2.5° latitude bands from the original resolutions of 0.5° × 0.5° for VEGAS, 5.0° × 5.0° for Jena99 and 1.0° × 1.0° for CarbonTracker.
