Deoras et al. (2026) The Role of Dry Intrusions in Breaks of the Indian Summer Monsoon

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2026
• Date: 2026-01-13
• Authors: Akshay Deoras, Andrew G. Turner, Ambrogio Volonté, R. Schiemann, Laura J. Wilcox, Arathy Menon
• DOI: 10.1175/jcli-d-25-0004.1

Research Groups

Not specified in the abstract.

Short Summary

This study investigates the role of dry intrusions in Indian Summer Monsoon (ISM) breaks, finding that most breaks are associated with midlevel dry intrusions originating from arid regions to the west and northwest of India, which stabilize the troposphere and inhibit deep convection.

Objective

• To understand the role of dry intrusions in Indian Summer Monsoon (ISM) breaks during the period 1940–2023.

Study Configuration

• Spatial Scale: Indian subcontinent, specifically northwest India and adjoining eastern Pakistan, and arid regions to the west and northwest of India.
• Temporal Scale: 1940–2023 for historical analysis; event-scale timing relative to breaks (e.g., ~7 days prior, 2–3 days prior).

Methodology and Data

• Models used: Not applicable for primary analysis; reanalysis data used.
• Data sources: Observations, fifth generation ECMWF atmospheric reanalysis (ERA5). An index based on moisture deficit was developed to identify dry intrusions.

Main Results

• Most Indian Summer Monsoon (ISM) breaks are associated with dry intrusions emanating from arid regions to the west and northwest of India.
• These dry intrusions begin to enter India approximately 7 days prior to the middle day of breaks.
• They reach peak strength over northwest India and adjoining eastern Pakistan 2–3 days prior to the middle day of breaks.
• Vertical profiles reveal these are midlevel dry intrusions, similar to those driving the direction of ISM withdrawal.
• As breaks evolve, these dry intrusions deepen throughout their horizontal extent and descend into the country, stabilizing the troposphere and creating an unfavorable environment for deep convection.
• Extended breaks are preceded by stronger dry intrusions.
• The study establishes a causal relationship between midlevel dry intrusions and ISM breaks.

Contributions

• Establishes a causal relationship between midlevel dry intrusions and Indian Summer Monsoon (ISM) breaks, addressing a previously less understood aspect compared to their role in ISM onset and withdrawal.
• Develops a novel index based on moisture deficit for identifying dry intrusions.
• Provides insights that could improve forecasts of ISM breaks, offering benefits for long-term planning by stakeholders.

Funding

Not specified in the abstract.

Citation

@article{Deoras2026Role,
  author = {Deoras, Akshay and Turner, Andrew G. and Volonté, Ambrogio and Schiemann, R. and Wilcox, Laura J. and Menon, Arathy},
  title = {The Role of Dry Intrusions in Breaks of the Indian Summer Monsoon},
  journal = {Journal of Climate},
  year = {2026},
  doi = {10.1175/jcli-d-25-0004.1},
  url = {https://doi.org/10.1175/jcli-d-25-0004.1}
}