Land-atmosphere fluxes during hydro-meteorological extremes: comparing high-resolution upscaled fluxes with site-level observations

Friday, 19 December 2014: 11:35 AM
Miguel D Mahecha1, Martin Jung1, Jannis von Buttlar2, Alexander Knohl3, Dario Papale4, Anja Rammig5, Jakob Zscheischler6 and Markus Reichstein1, (1)Max Planck Institute for Biogeochemistry, Jena, Germany, (2)Max-Planck-Institute for Biogeochemistry, Jena, Germany, (3)University of Göttingen, Göttingen, Germany, (4)Tuscia University, Department for Innovation in Biological, Agro-food and Forest systems (DIBAF), Viterbo, Italy, (5)Potsdam Institute for Climate Impact Research, Potsdam, Germany, (6)Max Planck Institute for Biogeochemistry, Tübingen, Germany
Multiple lines of evidence indicate that hydro-meteorological extreme events significantly alter regional water and carbon balances. Our aim is to understand the origins and effects of large-scale spatiotemporal extremes in land-atmosphere carbon and energy fluxes. The analsis is based an ensemble of global high-resolution carbon and energy flux products (FLUXCOM). This ensemble product is derived from upscaling FLUXNET eddy covariance observations with multiple machine learning methods. The FLUXCOM data cover the period 2001-2012 at 8 daily temporal and 0.0833 degree spatial resolution. We confront the signatures of extreme events detected in upscaled land-atmosphere fluxes to an analogous evaluation of FLUXNET site-level eddy covariance data. We discuss under which circumstances observed site-level responses to climate extremes deviate from results of the upscaled data. In particular we address the question in which ecosystems droughts act as key triggers of extreme anomalies in land-atmosphere fluxes.