Ji et al. (2025) In Situ Observations Reveal That the South Asian Summer Monsoon Weakens Aerosol Cloud Activation Over the Southern Tibetan Plateau

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

Identification

• Journal: Geophysical Research Letters
• Year: 2025
• Date: 2025-12-26
• Authors: Zhao Ji, Yuan Wang, Jiming Li, Ping Zhang, Fang Fang, Qiudi Xu, Ruling Lv, Jinsen Shi, Jianping Huang
• DOI: 10.1029/2025gl118406

Research Groups

Not explicitly specified in the abstract.

Short Summary

This study investigates the impact of the South Asian Summer Monsoon (SASM) on aerosol activation over the southern Tibetan Plateau using in situ measurements. It reveals a weak aerosol activation capacity and a significant negative correlation between SASM intensity and aerosol activation, attributed to enhanced wet scavenging during stronger monsoonal transport.

Objective

• To investigate the impact of the South Asian Summer Monsoon (SASM) on aerosol activation capacity over the southern Tibetan Plateau.

Study Configuration

• Spatial Scale: Southern Tibetan Plateau, specifically Mount Qomolangma Station.
• Temporal Scale: During the 2024 South Asian Summer Monsoon.

Methodology and Data

• Models used: Not specified.
• Data sources: In situ measurements of aerosol activation capacity, hygroscopicity, and cloud condensation nuclei (CCN) concentrations.

Main Results

• Weak aerosol activation capacity was observed over the southern Tibetan Plateau.
• Hygroscopicity parameter values were mostly below 0.1.
• Daily-mean cloud condensation nuclei (CCN) concentrations at 0.2% supersaturation ranged from 5 x 10^6 to 282 x 10^6 per cubic meter.
• CCN concentration, activation fraction, and hygroscopicity all exhibited significant negative correlations with SASM intensity.
• Stronger monsoonal transport reduces aerosol activation as clouds.
• This reduction is attributed to enhanced cloud formation, precipitation, and wet scavenging due to orographic lifting of monsoon air masses.

Contributions

• Provides novel in situ observations of aerosol activation capacity over the southern Tibetan Plateau, a region with limited prior data.
• Establishes a clear negative correlation between South Asian Summer Monsoon intensity and aerosol activation, clarifying a previously unclear interaction.
• Offers mechanistic insights into how monsoonal transport influences aerosol-cloud interactions through wet scavenging in a climatically sensitive region.

Funding

Not specified in the abstract.

Citation

@article{Ji2025Situ,
  author = {Ji, Zhao and Wang, Yuan and Li, Jiming and Zhang, Ping and Fang, Fang and Xu, Qiudi and Lv, Ruling and Shi, Jinsen and Huang, Jianping},
  title = {In Situ Observations Reveal That the South Asian Summer Monsoon Weakens Aerosol Cloud Activation Over the Southern Tibetan Plateau},
  journal = {Geophysical Research Letters},
  year = {2025},
  doi = {10.1029/2025gl118406},
  url = {https://doi.org/10.1029/2025gl118406}
}