TY - JOUR
T1 - Carbon Dioxide Physiological Forcing Dominates Projected Eastern Amazonian Drying
AU - Richardson, T. B.
AU - Forster, P. M.
AU - Andrews, T.
AU - Boucher, O.
AU - Faluvegi, G.
AU - Fläschner, D.
AU - Kasoar, M.
AU - Kirkevåg, A.
AU - Lamarque, J. F.
AU - Myhre, G.
AU - Olivié, D.
AU - Samset, B. H.
AU - Shawki, D.
AU - Shindell, D.
AU - Takemura, T.
AU - Voulgarakis, A.
N1 - Funding Information:
CMIP5 and PDRMIP model output is publicly available for download (see http://pcmdi9.llnl.gov and http://www. cicero.uio.no/en/PDRMIP/PDRMIP-data- access, respectively). T. B. R. was supported by a NERC CASE award in collaboration with the Met Office NE/K007483/1 and NERC grant NE/N006038/1. P. M. F. was supported by a Royal Society Wolfson Merit Award and NERC grant NE/N006038/1. T. A. was supported by the Newton Fund through the Met Office Climate Science for Service Partnership Brazil (CSSP Brazil). B. H. S. and G. M. were funded by the Research Council of Norway, through the grant NAPEX (229778). D. S. and G. F. thank NASA GISS for funding and acknowledge the NASA High-End Computing Program through the NASA Center for Climate Simulation at Goddard Space Flight Center for computational resources. O. B. acknowledges HPC resources from TGCC under the gencmip6 allocation provided by GENCI (Grand Equipement National de Calcul Intensif). T. T. is supported by the NEC SX-ACE supercomputer system of the National Institute for Environmental Studies, Japan, the Environmental Research and Technology Development Fund (S-12-3) of the Ministry of Environment, Japan, and JSPS KAKENHI grant JP15H01728 and JP15K12190. M. K., D. S., and A. V. were supported by the Natural Environment Research Council under grant NE/K500872/1 and from the Grantham Institute at Imperial College. Simulations with HadGEM2 and HadGEM3-GA4 were performed using the MONSooN system, a collaborative facility supplied under the Joint Weather and Climate Research Programme, which is a strategic partnership between the Met Office and the Natural Environment Research Council. D. O. and A. K. were supported by the Norwegian Research Council through the projects EVA (grant 229771), EarthClim (207711/E10), NOTUR (nn2345k), and NorStore (ns2345k).
Publisher Copyright:
©2018. The Authors.
PY - 2018/1/1
Y1 - 2018/1/1
N2 - Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.
AB - Future projections of east Amazonian precipitation indicate drying, but they are uncertain and poorly understood. In this study we analyze the Amazonian precipitation response to individual atmospheric forcings using a number of global climate models. Black carbon is found to drive reduced precipitation over the Amazon due to temperature-driven circulation changes, but the magnitude is uncertain. CO2 drives reductions in precipitation concentrated in the east, mainly due to a robustly negative, but highly variable in magnitude, fast response. We find that the physiological effect of CO2 on plant stomata is the dominant driver of the fast response due to reduced latent heating and also contributes to the large model spread. Using a simple model, we show that CO2 physiological effects dominate future multimodel mean precipitation projections over the Amazon. However, in individual models temperature-driven changes can be large, but due to little agreement, they largely cancel out in the model mean.
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U2 - 10.1002/2017GL076520
DO - 10.1002/2017GL076520
M3 - Article
AN - SCOPUS:85044418652
VL - 45
SP - 2815
EP - 2825
JO - Geophysical Research Letters
JF - Geophysical Research Letters
SN - 0094-8276
IS - 6
ER -
