The Indian Institute of Tropical Meteorology (IITM), under the Ministry of Earth Sciences (MoES), had conducted a research study named Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) during 2018-2019. The CAIPEEX study was carried out using specially hired cloud seeding and research aircraft over the rain shadow region of the Indian peninsula. The study has drawn guidelines for conducting cloud seeding over the rain shadow region.

IITM has developed the knowledge and expertise in the subject. The research and technology capabilities are being developed at IITM under the Mission Mausam Weather_MoD vertical. This includes the development of a 16m tall cloud chamber, the hiring of seeding aircraft, the collaborative development of cloud seeding drones, seeding materials, and dispensers, and other relevant technology with industry and startup companies. There will be capacity development in the country. Operational readiness is hindered by not having the aircraft at disposal and the associated permissions required to operate in the areas relevant for weather modification applications. Although most of the relevant technology is available for import, more development is needed in India to achieve operational readiness.

Cloud seeding tests during the CAIPEEX was conducted as a research experiment in 2018 and 2019 over the rain shadow region of Solapur, Maharastra. The main objectives were:

• • to investigate aerosol-cloud-precipitation interaction-the science of cloud seeding and
  • to conduct the randomized cloud seeding to investigate the impact on surface rainfall as per the recommendations of the World Meteorological Organization (WMO).

The report was released to the public and is available at the below link:

https://www.tropmet.res.in/~lip/Publication/Technical-Reports/CAIPEEX-Report-July2023.pdf    

The report gives a scientific experiment strategy for enhancing rainfall from warm-based clouds. It was found that rainfall can be enhanced by up to ≅ 46±13 per cent at some locations, as indicated by the Automatic Rain Gauges, and on average, and ≅ 18±2.6 per cent in a 100 square kilometres (km²) area downwind of the seeding location. Detailed scientific publication is available at: https://doi.org/10.1175/BAMS-D-21-0291.1

Potential applications include:

• A targeted cloud seeding effort for catchment-scale applications to enhance rainfall.
• The suppression of rainfall by overseeding.
• Other relevant targeted weather modification aspects include fog suppression, hail suppression, marine cloud brightening, etc.
• The intervention in extreme weather events has significant uncertainty.

The Indian Institute of Tropical Meteorology (IITM), under Ministry of Earth Sciences (MoES) had conducted a research study named Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) and IITM had developed the knowledge and expertise in the subject and continuously working on this.

The environmental and health hazards of cloud seeding and whether cloud seeding-induced rainfall can help reduce air pollution particularly in highly polluted urban areas is an area of research to be investigated with proper documentation and investigation following the guidelines developed in the CAIPEEX. This is the prerequisite for Government policy on the regulation and future deployment of cloud seeding technology in the country.

This information was given by Dr. Jitendra Singh, Union Minister of State (Independent Charge) for Science and Technology, Earth Sciences, MoS PMO, MoS Personnel, Public Grievances & Pensions, Department of Atomic Energy and Department of Space, in a written reply in the Lok Sabha today.

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NKR/PSM

(Release ID: 2147269)