Patil et al. (2026) Phase Transitions in Climate Network Unravel the Large-Scale Onset and Withdrawal of Indian Monsoon

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-08-20
• Authors: Yukta Patil, Gaurav Chopra, Shruti Tandon, B. N. Goswami, R. I. Sujith
• DOI: 10.1175/jcli-d-25-0384.1

Research Groups

• Centre of Excellence for Studying Critical Transitions in Complex Systems, Indian Institute of Technology Madras, Chennai, India
• Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai, India
• Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi, India
• ST Radar Centre, Gauhati University, Guwahati, India

Short Summary

This study proposes a novel transdisciplinary approach to define the onset and withdrawal of the Indian monsoon at every location by tracking the largest cluster of rainfall onsets in a climate network. The research establishes monsoon as a phase transition in the framework of climate networks.

Objective

• To develop an objective method for defining the large-scale onset and withdrawal of monsoon at every location.
• To understand the emergence and spatial spread of Indian monsoon using network science.

Study Configuration

• Spatial Scale: Planetary scale, with focus on India and surrounding regions.
• Temporal Scale: Seasonal migration of the planetary-scale convectively coupled system of intertropical convergence zone.

Methodology and Data

• Models used: Climate networks and network science techniques.
• Data sources: Satellite data, reanalysis datasets (e.g., ERA5), and observational records.

Main Results

• The study establishes that monsoon onset is a phase transition in the framework of climate networks.
• Climatologically, the large-scale onset over peninsular India occurs after a large-scale cluster is established over northeast India (NEI).
• The cluster from NEI propagates west and merges with a cluster over the peninsula, establishing a planetary-scale monsoon system that progresses northward consistently.

Contributions

• This study provides an objective method for defining the large-scale onset and withdrawal of monsoon at every location.
• It establishes monsoon as a phase transition in the framework of climate networks, providing new insights into the emergence and spatial spread of Indian monsoon.

Funding

• Centre of Excellence for Studying Critical Transitions in Complex Systems, Indian Institute of Technology Madras, Chennai, India (funding source not specified)
• Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai, India (funding source not specified)
• Department of Applied Mechanics, Indian Institute of Technology Delhi, New Delhi, India (funding source not specified)
• ST Radar Centre, Gauhati University, Guwahati, India (funding source not specified)

Citation

@article{Patil2026Phase,
  author = {Patil, Yukta and Chopra, Gaurav and Tandon, Shruti and Goswami, B. N. and Sujith, R. I.},
  title = {Phase Transitions in Climate Network Unravel the Large-Scale Onset and Withdrawal of Indian Monsoon},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0384.1},
  url = {https://doi.org/10.1175/jcli-d-25-0384.1}
}