Title: Recent Decline in the Global Land Evapotranspiration Trend Due to Limited Moisture Supply
Authors: JUNG MartinREICHSTEIN MarkusCIAIS PhilippeSENEVIRATNE Sonia I.SHEFFIELD JustinGOULDEN Michael L.BONAN GordonCHEN JiquanCESCATTI AlessandroDE JEU RichardDOLMAN A. JohannesEUGSTER WernerGERTEN DieterGIANELLE DamianoGOBRON NadineHEINKE JensKIMBALL JohnLAW Beverly E.MONTAGNANI LeonardoMU QiaozhenMUELLER BrigitteOLESON KeithPAPALE DarioRICHARDSON Andrew D.ROUPSARD OlivierRUNNING SteveTOMELLERI EnricoVIOVY NicolasWEBER UlrichWILLIAMS ChristopherWOOD EricZAEHLE SonkeZHANG Ke
Citation: NATURE vol. 467 p. 951-954
Publisher: NATURE PUBLISHING GROUP
Publication Year: 2010
JRC N°: JRC60027
ISSN: 0028-0836
URI: http://www.nature.com/nature/journal/v467/n7318/full/nature09396.html
http://publications.jrc.ec.europa.eu/repository/handle/JRC60027
DOI: 10.1038/nature09396
Type: Articles in Journals
Abstract: More than half of the solar energy absorbed by land surfaces is currently used to evaporate water1. Climate change is expected to intensify the hydrological cycle2 and to alter evapotranspiration (ET), with implications for ecosystem services and feedbacks to regional and global climate. ET changes may already be under way but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the land water cycle - a key diagnostic of the impacts of climate change and variability - remain uncertain. Using a global monitoring network3, meteorological and remote sensing observations, and a machine learning algorithm4 we provide a data-driven estimate of global land ET from 1982 to 2008. In addition we assessed ET variations over the same time period with an ensemble of process-based land surface models. Our results suggest that global annual ET increased on average by 7.1 ± 1.0 mm per year per decade from 1982 to 1997. Then, coincident with the last major El Nino event in 1998, the global ET increase appears to have ceased until 2008. This downward trend change was driven primarily by moisture limitation in the southern hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil moisture limitation on ET largely explains the recent decline of the global land ET trend . Whether the changing behaviour of ET is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for Earth System Science.
JRC Institute:Institute for Environment and Sustainability

Files in This Item:
There are no files associated with this item.


Items in repository are protected by copyright, with all rights reserved, unless otherwise indicated.