edu.ucar.opensky::articles:14518 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:19:08.906355 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7639qr0 Predicting the response of the Amazon rainforest to persistent drought conditions under current and future climates: A major challenge for global land surface models 2014-12-10T00:00:00Z publication https://n2t.org/ark:/85065/d7639qr0 https://doi.org/10.5194/gmd-7-2933-2014 Joetzjer, E. author Delire, C. author Douville, H. author Ciais, P. author Decharme, B. author Fisher, Rosemary A. author Christoffersen, B. author Calvet, J. author Da Costa, A. author Ferreira, L. author Meir, P. author UCAR/NCAR - Library publisher While a majority of global climate models project drier and longer dry seasons over the Amazon under higher CO₂ levels, large uncertainties surround the response of vegetation to persistent droughts in both present-day and future climates. We propose a detailed evaluation of the ability of the ISBACC (Interaction Soil–Biosphere–Atmosphere Carbon Cycle) land surface model to capture drought effects on both water and carbon budgets, comparing fluxes and stocks at two recent throughfall exclusion (TFE) experiments performed in the Amazon. We also explore the model sensitivity to different water stress functions (WSFs) and to an idealized increase in CO₂ concentration and/or temperature. In spite of a reasonable soil moisture simulation, ISBACC struggles to correctly simulate the vegetation response to TFE whose amplitude and timing is highly sensitive to the WSF. Under higher CO₂ concentrations, the increased water-use efficiency (WUE) mitigates the sensitivity of ISBACC to drought. While one of the proposed WSF formulations improves the response of most ISBACC fluxes, except respiration, a parameterization of drought-induced tree mortality is missing for an accurate estimate of the vegetation response. Also, a better mechanistic understanding of the forest responses to drought under a warmer climate and higher CO₂ concentration is clearly needed. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright Author(s) 2014. This work is distributed under the Creative Commons Attribution 3.0 License. None eng geoscientificInformation