Kamat et al. (2025) Dynamics of convective clouds near and below the lifting condensation level over a semi-arid Western-Indian region

Identification

• Journal: Atmospheric Research
• Year: 2025
• Date: 2025-10-06
• Authors: Dharmendra Kumar Kamat, Som Sharma, Kondapalli Niranjan Kumar, Prashant Kumar, Sourita Saha, Hassan Benchérif
• DOI: 10.1016/j.atmosres.2025.108542

Research Groups

• Physical Research Laboratory, Ahmedabad, India
• Indian Institute of Technology Gandhinagar, Gandhinagar, India
• National Centre for Medium Range Weather Forecasting, Noida, India
• Space Applications Centre, Ahmedabad, India
• Scripps Institution of Oceanography, University of California, San Diego, CA, USA
• University De la Reunion, Reunion Island, France

Short Summary

This study investigates the occurrence of convective clouds forming below the lifting condensation level (LCL) over a semi-arid region in Western India. It finds that such anomalous clouds occur predominantly during post-monsoon and winter months, associated with thermal inversions and specific surface sensible and latent heat flux conditions.

Objective

• To investigate the occurrence and characteristics of clouds forming below the lifting condensation level (LCL) over Ahmedabad, a semi-arid region in Western India, during 2022–2024.

Study Configuration

• Spatial Scale: Ahmedabad, a semi-arid region in Western India.
• Temporal Scale: 2022–2024 (3 years).

Methodology and Data

• Models used: An analytical LCL formulation derived from surface temperature and relative humidity.
• Data sources: Radiosonde data (for validation), surface temperature, and relative humidity observations.

Main Results

• An analytical LCL formulation showed minimal bias when validated against radiosonde data.
• Convective clouds near the LCL are most frequent during the monsoon season.
• Anomalous cloud formations below the LCL were observed during post-monsoon and winter months.
• The mean cloud base height (CBH) for these low-level clouds was 1044 ± 135 m.
• These clouds predominantly occurred between 06:00 and 12:00 UTC.
• They were associated with a strong thermal inversion below the LCL.
• Surface temperatures during their occurrence ranged from 24 °C to 37 °C, with relative humidity between 17 % and 49 %.
• Surface sensible heat flux was lower than for clouds forming near the LCL but comparable to clear-sky conditions.
• Surface latent heat flux was higher than in clear-sky conditions but lower than for clouds forming near the LCL, averaging 147 ± 74 W/m².

Contributions

• Provides an improved understanding of cloud formation processes, particularly for clouds forming below the LCL, in semi-arid environments.
• Highlights the critical role of thermodynamic stability and surface heat fluxes in modulating cloud formation in these regions.
• Offers insights essential for enhancing weather prediction models and refining convective parameterization schemes in numerical weather and climate models, especially in arid and semi-arid regions.

Funding

• Not specified in the provided text.

Citation

@article{Kamat2025Dynamics,
  author = {Kamat, Dharmendra Kumar and Sharma, Som and Kumar, Kondapalli Niranjan and Kumar, Prashant and Saha, Sourita and Benchérif, Hassan},
  title = {Dynamics of convective clouds near and below the lifting condensation level over a semi-arid Western-Indian region},
  journal = {Atmospheric Research},
  year = {2025},
  doi = {10.1016/j.atmosres.2025.108542},
  url = {https://doi.org/10.1016/j.atmosres.2025.108542}
}