Root mean square of annual net carbon flux obtained from time-dependent inverse solutions  for the period 1990 – 2001 and for regions based on TransCom [20, 108]. NH (Northern Hemisphere land) includes temperate and boreal Asia, temperate and boreal North America, and Europe, SH (Southern Hemisphere land) includes temperate South America, Australia and New Zealand, Tropical includes tropical America, Africa and tropical Asia, and Amer. abbreviates America.
Williams et al. Carbon Balance and Management 2007 2:3 doi:10.1186/1750-0680-2-3