Topology and seasonal evolution of the network of extreme precipitation over the Indian subcontinent and Sri Lanka
- 1PIK Potsdam Institute of Climate Impact Research, P.O. Box 601203, 14412 Potsdam, Germany
- 2Department of Physics, Humboldt-Universität zu Berlin, Newtonstr. 15, 12489 Berlin, Germany
- 3University of Michigan, Ann Arbor, Michigan, USA
- 4Department of Geography, University of California, Santa Barbara, USA
- 5University of Potsdam, Institute of Earth and Environmental Science, Karl-Liebknecht-Str. 24–25, 14476 Potsdam-Golm, Germany
- 6Institute for Complex Systems and Mathematical Biology, University of Aberdeen, Aberdeen, AB243UE, UK
Abstract. This paper employs a complex network approach to determine the topology and evolution of the network of extreme precipitation that governs the organization of extreme rainfall before, during, and after the Indian Summer Monsoon (ISM) season. We construct networks of extreme rainfall events during the ISM (June–September), post-monsoon (October–December), and pre-monsoon (March–May) periods from satellite-derived (Tropical Rainfall Measurement Mission, TRMM) and rain-gauge interpolated (Asian Precipitation Highly Resolved Observational Data Integration Towards the Evaluation of Water Resources, APHRODITE) data sets. The structure of the networks is determined by the level of synchronization of extreme rainfall events between different grid cells throughout the Indian subcontinent. Through the analysis of various complex-network metrics, we describe typical repetitive patterns in North Pakistan (NP), the Eastern Ghats (EG), and the Tibetan Plateau (TP). These patterns appear during the pre-monsoon season, evolve during the ISM, and disappear during the post-monsoon season. These are important meteorological features that need further attention and that may be useful in ISM timing and strength prediction.