Fig. 3: Historical tropical land water–carbon interannual correlations in observations and models.
From: Increasingly negative tropical water–interannual CO2 growth rate coupling
a, Changes in interannual correlations and partial correlations between tropical water availability and land carbon fluxes from the previous 27 years (1960–1986) to the recent 27 years (1988–2014). For partial correlations, tropical temperature is controlled. All variables are detrended at yearly scale in each corresponding window. For observations, CGR/RLS, reconstructed tropical WS/tropical LagP and tropical temperature are used for computations (n = 4). For models, global NEE, tropical total soil moisture and tropical temperature from each model are used for computations (coupled models, n = 9; offline models, n = 6). Box plots show the distribution of estimates for all models, solid horizontal lines indicate the median values, boxes cover the interquartile range, and vertical lines reach the 5th and 95th percentiles. b, Same as a but showing the interannual correlations and partial correlations between tropical water availability and land carbon fluxes during 1960–2014.
