Verma et al. (2025) Indian Summer Monsoon During the Medieval Climate Anomaly With a Steady Trend From 1140 to 1250 CE

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

Identification

• Journal: Journal of Geophysical Research Atmospheres
• Year: 2025
• Date: 2025-12-26
• Authors: Yachna Verma, A.K. Gupta, Naveen Gandhi, Hai Cheng, Priyantan Gupta, Som Dutt
• DOI: 10.1029/2025jd044490

Research Groups

Not explicitly mentioned in the abstract.

Short Summary

This study reconstructs Indian Summer Monsoon (ISM) dynamics during the Medieval Climate Anomaly (∼722 to 1250 CE) using a high-resolution speleothem record from Meghalaya, revealing distinct wet and dry phases and attributing multidecadal variability to solar activity and subdecadal variability to El Niño-Southern Oscillation.

Objective

• To reconstruct and understand the dynamics of the Indian Summer Monsoon (ISM) through the Medieval Climate Anomaly (∼722 to 1250 CE) using a high-resolution speleothem record.

Study Configuration

• Spatial Scale: Bylliat cave, Meghalaya, northeastern Himalaya (regional scale).
• Temporal Scale: Approximately 722 to 1250 CE (millennial scale, covering the Medieval Climate Anomaly).

Methodology and Data

• Models used: None; observational study using paleoclimate proxies.
• Data sources: U-Th dated speleothem record from Bylliat cave, δ¹⁸O values from speleothem, petrographic analyses of speleothem.

Main Results

• A distinctly wet phase occurred between approximately 722 and 775 CE.
• A marked decline in precipitation was observed from approximately 775 to 850 CE.
• A prolonged drought-like condition prevailed between approximately 850 and 890 CE.
• Wetter conditions returned to the northeastern Himalaya from approximately 890 to 980 CE.
• The monsoon was relatively stable from approximately 1140 to 1250 CE, analogous to modern ISM patterns in a non-El Niño scenario.
• Multidecadal ISM variability during the Medieval Climate Anomaly was primarily modulated by solar activity and consequent latitudinal migration of the Intertropical Convergence Zone.
• Subdecadal ISM variability was closely linked to changes in the El Niño-Southern Oscillation.
• Pronounced wet conditions from the eighth to thirteenth centuries are believed to have promoted agricultural expansion and crop diversification across India, potentially influencing cultural and political change in eastern regions.

Contributions

• Provides a new, high-resolution U-Th dated speleothem record offering detailed insights into ISM dynamics during the Medieval Climate Anomaly.
• Identifies specific wet and dry phases within the MCA, enhancing the understanding of regional paleoclimate.
• Establishes distinct modulators for multidecadal (solar activity, ITCZ) and subdecadal (ENSO) ISM variability during this period.
• Discusses the potential societal impacts of these climatic conditions on agriculture, culture, and politics in the Indian subcontinent.

Funding

Not explicitly mentioned in the abstract.

Citation

@article{Verma2025Indian,
  author = {Verma, Yachna and Gupta, A.K. and Gandhi, Naveen and Cheng, Hai and Gupta, Priyantan and Dutt, Som},
  title = {Indian Summer Monsoon During the Medieval Climate Anomaly With a Steady Trend From 1140 to 1250 CE},
  journal = {Journal of Geophysical Research Atmospheres},
  year = {2025},
  doi = {10.1029/2025jd044490},
  url = {https://doi.org/10.1029/2025jd044490}
}