Precipitation Enhancement - Puglia, Italy


Atmospheric water in the form of precipitation is one of the primary sources of fresh water in the world. However, a large amount of water present in clouds never is transformed into precipitation on the ground. This has prompted scientists and engineers to explore the possibility of augmenting water supplies by means of cloud seeding. Although some projects have successfully documented increases in precipitation due to seeding, others have shown a decrease while the majority of projects have yielded inconclusive results. The reason for this is that physical mechanisms of cloud and precipitation development in the atmosphere are much more complex than earlier anticipated, thus the initial optimism in the 1950's and 1960's has given way to a more cautious approach.

Water is of critical importance to economic activities in the Puglia region of Italy. Puglia is one of the primary agricultural areas in Italy and water for irrigation is widely applied. During the past several decades, recurring droughts have had severe impacts on reservoir levels and underground water supplies and, therefore, the economy. Underground water levels have gradually declined with the effect that along several coastal parts sea-water intrusion has become a major problem. Authorities have been investigating the potential for cloud seeding to enhance rainfall since the middle of the 1980's which resulted in several programs conducted in this region in the later 1980's and early 1990's. The continuing water shortage in this region has prompted the authorities to once again explore the possibility of enhancing precipitation via cloud seeding.

Before any cloud seeding operations are conducted, it is important to determine the existance and frequency of occurances of suitable clouds for any given area. There are two important aspects to this investigation. 1) Determine, based on climatological datea, what the frequency and type of clouds there are and how precipitation is associated with these clouds, and 2) Determine the microphysical and dynamical characteristics of the natural clouds of the region. Armed with this knowledge, the most effective cloud seeding technique can be determined.

Scientists from the Research Applications Laboratory (RAL) of the National Center for Atmospheric Research (NCAR), in colloboration with AEROTECH SA, will assist the authorities in Puglia, Italy in conducting a feasibility study to design and execute precipitation enhancement operations via cloud seeding throughout the region. The field campaign commences on 1 November 2004 and will continue through 1 March 2005. This website is designed to support the field campaign.