caa a22 4500 605471169 CHVBK 20210128100331.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s00382-014-2265-7 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2265-7 Complex network analysis helps to identify impacts of the El Niño Southern Oscillation on moisture divergence in South America [Elektronische Daten] [Niklas Boers, Reik Donner, Bodo Bookhagen, Jürgen Kurths] We investigate the temporal evolution of moisture divergence and its spatial clustering properties over South America. Our analysis focuses on dependencies on the phase of the El Niño Southern Oscillation (ENSO). Moisture divergence is computed from daily reanalysis data of vertically integrated moisture flux provided by Modern-Era Retrospective Analysis for Research and Applications for the time period from 1979 to 2010. We use a sliding-window approach to construct a sequence of complex networks, each obtained from synchronization of events of strong positive (negative) moisture divergence, which we interpret as strong evapotranspiration (precipitation) events. We make the following three key observations: (1) Moisture divergence values over the Amazon rainforest are typically higher during positive ENSO periods (El Niño events). (2) The spatial coherence of strong positive (upwelling) events assumes a characteristic pattern of reduced coherence in this area during El Niño conditions. This influence of ENSO on moisture divergence and its spatial coherence is dominated by the El Niño events of 1982, 1987, and 1997. (3) The clustering characteristics of the obtained climate networks qualitatively agree with the spatial distribution of connected regions with simultaneous events (i.e., events that occur at the same time), but provide a more detailed view on the spatial organization of strong atmospheric upwelling events. Interestingly, no comparable results are found for negative extremes of moisture divergence (strong precipitation events). Springer-Verlag Berlin Heidelberg, 2014 Moisture divergence nationallicence Extreme events nationallicence South American climate nationallicence El Niño Southern Oscillation nationallicence Complex networks nationallicence Boers Niklas Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut Donner Reik Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut Bookhagen Bodo Department of Geography, University of California at Santa Barbara, Ellison Hall 1832, 93106, Santa Barbara, CA, USA aut Kurths Jürgen Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut Climate Dynamics Springer Berlin Heidelberg 45/3-4(2015-08-01), 619-632 0930-7575 45:3-4<619 2015 45 382 https://doi.org/10.1007/s00382-014-2265-7 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2265-7 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Boers Niklas Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut NATIONALLICENCE 700 1- Donner Reik Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut NATIONALLICENCE 700 1- Bookhagen Bodo Department of Geography, University of California at Santa Barbara, Ellison Hall 1832, 93106, Santa Barbara, CA, USA aut NATIONALLICENCE 700 1- Kurths Jürgen Potsdam Institute for Climate Impact Research, P. O. Box 601203, 14412, Potsdam, Brandenburg, Germany aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/3-4(2015-08-01), 619-632 0930-7575 45:3-4<619 2015 45 382