24may2012-India CAIPEEX Program

India CAIPEEX Program

The Aerosol and Precipitation group has been engaged in scientific research to evaluate precipitation enhancement techniques for several decades. Our group has focused on analyzing existing data and collecting specialized data for assessing current weather modification projects or for developing feasibility plans for cloud seeding activities in the USA, United Arab Emirates, Australia, West Africa, India, Saudi Arabia, Oman, Indonesia, Thailand, Turkey, Mexico and Italy. Work accomplished in the last twenty years with hygroscopic seeding techniques has shown promising results in statistical field tests in South Africa, Mexico, and Australia. Associated cloud measurements and cloud model calculations have provided a physical basis to support the hypothesis that seeding with small hygroscopic particles at cloud base can, under some conditions, enhance rainfall.
The Indian Institute of Tropical Meteorology (IITM) has implemented a multi-year program to study cloud-aerosol interactions and cloud seeding. An Indian national research program called "Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX)" was begun in 2008, and in 2010, Phase II of CAIPEEX was executed during an intensive observation period (IOP) from August to November. The research work was lead by IITM with support and guidance by the RAL Aerosols and Precipitation group, Woodley Weather Consultants (WWC), Orsmond Aviation, and the University of the Witwatersrand (WITS). Local logistical support was contracted with Krishi Consultants.
The objective of CAIPEEX-II is to examine the variability of thermodynamic properties, aerosol, clouds, and precipitation through airborne and radar measurements over the central region of India during the monsoon period.

• The goals of the IOP were to (1) document these conditions and determine the suitability of clouds to cloud seeding and to determine the optimal methods to target clouds, and (2) measure effects of cloud seeding on cloud microstructure. The approach in measuring seeding effect was to recognize seeding opportunities, implement a seeding strategy, and evaluate the effects of seeding. This was done in an attempt to establish a cause-and-effect relationship between the seeding action and the changes in the cloud microphysical properties measured by the aircraft and radar.