Event synchrony measures for functional climate network analysis: A case study on South American rainfall dynamics

Author(s)

Wolf, Frederik ^{[1, 2, 3]} ; Bauer, Jurek ^[4] ; Boers, Niklas ^{[2, 3, 5, 6, 7]} ; Donner, V, Reik

Affiliation

^[1] Humboldt Univ, Dept Phys, Newtonstr 15, D-12489 Berlin - Germany

^[2] V, Potsdam Inst Climate Impact Res PIK, Telegrafenberg A56, D-14473 Potsdam - Germany

^[3] V, Leibniz Assoc, Telegrafenberg A56, D-14473 Potsdam - Germany

^[4] Georg August Univ, Inst Astrophys, Friedrich Hund Pl 1, D-37077 Gottingen - Germany

^[5] Free Univ Berlin, Dept Math & Comp Sci, Takustr 9, D-14195 Berlin - Germany

^[6] Univ Exeter, Global Syst Inst, Stocker Rd, Exeter EX4 4PY, Devon - England

^[7] Univ Exeter, Dept Math, Stocker Rd, Exeter EX4 4PY, Devon - England

• Document type: Journal article
• Source: Chaos; v. 30, n. 3 MAR 2020.
• Web of Science Citations: 1

Abstract

Understanding spatiotemporal patterns of climate extremes has gained considerable relevance in the context of ongoing climate change. With enhanced computational capacity, data driven methods such as functional climate networks have been proposed and have already contributed to significant advances in understanding and predicting extreme events, as well as identifying interrelations between the occurrences of various climatic phenomena. While the (in its basic setting) parameter free event synchronization (ES) method has been widely applied to construct functional climate networks from extreme event series, its original definition has been realized to exhibit problems in handling events occurring at subsequent time steps, which need to be accounted for. Along with the study of this conceptual limitation of the original ES approach, event coincidence analysis (ECA) has been suggested as an alternative approach that incorporates an additional parameter for selecting certain time scales of event synchrony. In this work, we compare selected features of functional climate network representations of South American heavy precipitation events obtained using ES and ECA without and with the correction for temporal event clustering. We find that both measures exhibit different types of biases, which have profound impacts on the resulting network structures. By combining the complementary information captured by ES and ECA, we revisit the spatiotemporal organization of extreme events during the South American Monsoon season. While the corrected version of ES captures multiple time scales of heavy rainfall cascades at once, ECA allows disentangling those scales and thereby tracing the spatiotemporal propagation more explicitly. Published under license by AIP Publishing. (AU)

• FAPESP's process: 11/50151-0 - Dynamical phenomena in complex networks: fundamentals and applications
• Grantee: Elbert Einstein Nehrer Macau
• Support Opportunities: Research Projects - Thematic Grants