@article{4c4dd5a48d804d62a3af94d548fe1b84,
title = "Warm spring reduced carbon cycle impact of the 2012 US summer drought",
abstract = "The global terrestrial carbon sink offsets one-third of the world's fossil fuel emissions, but the strength of this sink is highly sensitive to large-scale extreme events. In 2012, the contiguous United States experienced exceptionally warm temperatures and the most severe drought since the Dust Bowl era of the 1930s, resulting in substantial economic damage. It is crucial to understand the dynamics of such events because warmer temperatures and a higher prevalence of drought are projected in a changing climate. Here, we combine an extensive network of direct ecosystem flux measurements with satellite remote sensing and atmospheric inverse modeling to quantify the impact of the warmer spring and summer drought on biosphereatmosphere carbon and water exchange in 2012. We consistently find that earlier vegetation activity increased spring carbon uptake and compensated for the reduced uptake during the summer drought, which mitigated the impact on net annual carbon uptake. The early phenological development in the Eastern Temperate Forests played a major role for the continental-scale carbon balance in 2012. The warm spring also depleted soil water resources earlier, and thus exacerbated water limitations during summer. Our results show that the detrimental effects of severe summer drought on ecosystem carbon storage can be mitigated by warming-induced increases in spring carbon uptake. However, the results also suggest that the positive carbon cycle effect of warm spring enhances water limitations and can increase summer heating through biosphere-atmosphere feedbacks.",
keywords = "Biosphere Atmosphere feedbacks, Carbon uptake, Climate anomalies, Ecosystem fluxes, Eddy covariance",
author = "Sebastian Wolf and Keenan, {Trevor F.} and Fisher, {Joshua B.} and Baldocchi, {Dennis D.} and Desai, {Ankur R.} and Richardson, {Andrew D.} and Scott, {Russell L.} and Law, {Beverly E.} and Litvak, {Marcy E.} and Brunsell, {Nathaniel A.} and Wouter Peters and {Van Der Laan-Luijkx}, {Ingrid T.}",
note = "Funding Information: . We acknowledge support from the Carbon Dioxide Information Analysis Center at the Oak Ridge National Laboratory, particularly B. Yang. We thank D. M. Ricciuto for assistance with the gap-filling of climate data and M. Sikka for remote-sensing data processing. We thank all data contributors for this synthesis study, particularly P. Blanken, G. Bohrer, D. Bowling, S. Burns, K. L. Clark, D. Hollinger, S. Ma, Q. Mu, K. A. Novick, S. A. Papuga, F. Rahman, and M. Zhao. We thank K. A. Novick, G. Bohrer, E. van Gorsel, and E. Paul-Limoges for helpful comments on the manuscript. We also appreciate the constructive comments of the reviewers and the editor. This research was supported by the European Commission's FP7 Marie Curie International Outgoing Fellowship Grant 300083 (to S.W.). Funding for the AmeriFlux Management Project was provided by the US Department of Energy's Office of Science (Contract DE-AC02-05CH11231). T.F.K. acknowledges support from a Macquarie University Research Fellowship. J.B.F. carried out the research at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration, and acknowledges support from NASA's Terrestrial Hydrology Program. A.D.R. acknowledges support from the National Science Foundation (NSF), through the Macrosystems Biology program (Award EF-1065029) and the LTER program (DEB-1114804). M.E.L. acknowledges support from NASA ROSES (Award 0486V-874F). N.A.B. acknowledges support from the NSF EPSCoR program (EPS-0553722 and EPS-0919443) and the LTER program at the Konza Prairie Biological Station (DEB-0823341). W.P. and I.T.v.d.L.-L. acknowledge funding from NWO (SH-060-13) for computing time. I.T.v.d.L.-L. received financial support",
year = "2016",
month = may,
day = "24",
doi = "10.1073/pnas.1519620113",
language = "English (US)",
volume = "113",
pages = "5880--5885",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "21",
}