Dubai has suffered a event's audience of very rare flooding for the region, which is notoriously arid. This event surprised many given the low annual frequency of precipitation in this area. The floods occurred following intense and sudden rains, which exceeded the city's drainage capacity, causing significant accumulations of water in streets, infrastructure and residential areas.
Many have thought about cloud seeding, what is it?
The "cloud seeding" or "cloud seeding” is a weather modification technique that aims to increase precipitation, improve air quality or disperse fog. This method involves dispersing chemicals into clouds, such as silver iodide or sodium salts, which act as condensation nuclei, stimulating the formation of raindrops or ice crystals, which then fall to the ground as precipitation . The main goal of cloud seeding is often to increase water reserves in arid regions or to counteract prolonged droughts. However, it can also be used for other purposes, such as controlling rainfall in areas prone to flood risk or to reduce hail in agricultural areas.
Several countries around the world use cloud seeding for various purposes, mainly to increase rainfall and improve water resource management. Here are some examples:
United States: Cloud seeding is used in several states, such as California, Utah, and Colorado, to increase snowfall that feeds reservoirs and for water resource management.
China: China has one of the largest cloud seeding programs in the world. It uses this technology to fight drought and reduce pollution, as well as ensure adequate weather for major events, such as the Beijing Olympics in 2008.
United Arab Emirates: The Emirates has invested significantly in cloud seeding to increase rainfall in one of the world's driest climates. The country regularly experiments with new technologies and methods to optimize the effectiveness of this practice.
Australia: Australia has experimented with cloud seeding to improve rainfall in mountainous regions and for agricultural areas that suffer from periodic droughts.
India: India uses cloud seeding to address water challenges in some of its driest regions, such as Karnataka and Maharashtra, especially during low monsoon periods.
Thailand: Thailand uses cloud seeding to mitigate the effects of drought and control rainfall in some of its major agricultural regions.
In Italy
In Italy, cloud seeding has been explored and sometimes implemented, mainly with the aim of influencing precipitation in specific areas. The practice is not as widespread as in some other countries facing severe water shortages or extreme weather, but it has been used in specific contexts.
History and Applications
Historical experiments: In the 50s and 60s, Italy conducted cloud seeding experiments, particularly in the Alps, to increase snowfall and thus the availability of water for irrigation and hydroelectric production.
Hail prevention: In some regions, such as Friuli Venezia Giulia, cloud seeding attempts have been conducted to mitigate the formation of hail, which can seriously damage agricultural crops.
Contexts and Considerations
Regulation and public perception: The use of cloud seeding in Italy faces stringent environmental regulations and marked public sensitivity regarding environmental manipulations. Issues of safety and environmental impact are central to debates about the practice.
Research and collaboration: Italian universities and research centers participate in international studies and projects to explore cloud seeding methodologies and their possible impacts and benefits. International collaboration helps share advanced knowledge and technologies in this field.
Current situation
Currently, there are no large-scale cloud seeding programs in Italy. Studies and applications are more sporadic and limited to particular needs or specific research projects. The practice of cloud seeding in the Italian context remains an area of scientific and technological interest rather than a routine meteorological intervention.
How to cause cloud seeding
The process of cloud seeding occurs through a series of specific steps aimed at stimulating precipitation from clouds that would otherwise not precipitate or increase the amount of precipitation. Here are the main steps and methods used:
1. Cloud selection
The first step is to identify clouds suitable for seeding. Not all clouds are ideal candidates; clouds must have sufficient humidity and the appropriate thermal conditions to be effectively “seeded”. Generally, you choose between cumulus (which can lead to precipitation) and stratocumulus.
2. Dispersion of Condensation Nuclei
Once the appropriate clouds are identified, we proceed with the dispersion of particles on which moisture can condense. Commonly used materials include:
- Silver iodide: Very effective in catalyzing the freezing of water droplets in clouds below freezing.
- Sodium chloride (salt): Mainly used in higher temperature clouds.
- Dry ice (frozen carbon dioxide): Can be used to trigger the freezing and precipitation process in clouds with very low temperatures.
These substances are dispersed using specialized aircraft that fly through the clouds or with ground-based devices such as smoke generators or rocket launchers that push the particulates up into the clouds.
3. Precipitation Formation Process
After the nuclei disperse, silver iodide particles or other agents allow supercooled water droplets in the cloud to freeze or grow in size through accretion. This process increases the weight of water droplets until they are too heavy to remain suspended in the air, eventually falling to the ground as rain or snow.
4. Monitoring and Evaluation
The cloud seeding process requires careful monitoring and evaluation to determine the effectiveness of the operation. Weather radar, satellites and ground stations are used to monitor changes in precipitation and atmospheric conditions.
Ethical and Environmental Considerations
Cloud seeding raises ethical and environmental questions, including potential impacts on downstream regions, where changes in precipitation could negatively affect the environment and communities. Furthermore, the continued use of certain chemicals could have long-term effects on the ecosystem.
In summary, cloud seeding is a complex process that requires an in-depth understanding of weather conditions and sophisticated technology to implement effectively.
Conclusions
This technique was first used in the 40s and continues to be a topic of research and application in many countries around the world. Despite its potential, cloud seeding raises questions regarding its effectiveness, costs and environmental impacts, as well as debates over its regulation and the ethical implications of manipulating the climate.
