Thực hư CÔNG NGHỆ ĐUỔI MÂY: Liệu con người có thể làm chủ thời tiết? | Baram01 | Thế Giới

Key Concepts

• Cloud Seeding (Reo mây, Reo mưa nhân tạo): A technique to influence weather by dispersing substances into clouds to increase or decrease precipitation, or to dissipate fog and hail.
• Nuclei (Hạt nhân ngưng tụ): Tiny particles (e.g., silver iodide, salt, dry ice) introduced into clouds to encourage water vapor to condense into droplets or ice crystals.
• Glaciogenic Seeding (Reo mây lạnh): Cloud seeding for clouds with temperatures between -20°C and -7°C, using substances like silver iodide to promote ice crystal formation.
• Hygroscopic Seeding (Reo mây ấm): Cloud seeding for clouds with temperatures above 0°C, using substances like salt to attract water vapor and form larger droplets.
• Silver Iodide (AGI): A common substance used in cloud seeding due to its crystal structure resembling ice, promoting ice crystal formation in cold clouds.
• Sodium Chloride (NaCl): Salt, used in warm clouds to attract water vapor and facilitate droplet coalescence.
• Dry Ice (CO2 rắn): Solid carbon dioxide, used to rapidly cool areas in clouds, promoting ice crystal formation.
• Weather Modification: The broader field encompassing techniques like cloud seeding to alter weather patterns.
• Downdraft Impact: An indirect impact of cloud seeding where altered weather patterns in one area can affect adjacent regions.
• Transboundary Impact: The potential for weather modification activities in one country to affect the climate, agriculture, or water resources of neighboring countries.

Cloud Seeding: Understanding and Applications

This video explores the concept of cloud seeding, also known as artificial rainmaking, addressing the public's curiosity sparked by rumors of weather manipulation for national events. It clarifies that cloud seeding is not about "turning on and off" the weather like electricity, but rather about influencing existing cloud structures under specific conditions with varying degrees of certainty and risk.

1. Overview of Cloud Seeding

Definition and Principle: Cloud seeding is a technique used to directly influence clouds, aiming to increase or decrease precipitation (rain or snow), dissipate fog, or mitigate hail. The core principle involves introducing microscopic particles, termed "nuclei," into clouds. These nuclei act as condensation centers, encouraging water vapor to condense into water droplets or ice crystals, which then grow large enough to fall as precipitation. The World Meteorological Organization (WMO) defines cloud seeding as the dispersal of substances into clouds to alter their structure, thereby increasing rainfall, reducing hail, or dissipating fog.

Objectives: The primary goals of cloud seeding include:

• Increasing rainfall: To combat drought, replenish water sources, and assist in firefighting.
• Decreasing rainfall/Mitigating hail: To prevent flooding or damage from severe weather.
• Ensuring clear skies: For important national or international events.

Essentially, it's an effort to augment natural processes for water resource management and climate risk reduction, acknowledging inherent limitations in control.

Substances Used: Commonly used seeding agents include:

• Silver Iodide (AGI): Its crystal structure is similar to ice, making it effective in cold clouds (below 0°C) to promote ice crystal formation.
• Sodium Chloride (NaCl): Used in warm clouds (above 0°C) to attract water vapor and help smaller water droplets coalesce into larger ones.
• Dry Ice (Solid CO2): Rapidly cools the surrounding air, facilitating the formation of ice crystals from water vapor.

Limitations: Crucially, cloud seeding cannot create rain from a clear sky. It requires the presence of clouds with sufficient moisture. The effectiveness is contingent on numerous factors, including:

• Cloud moisture content
• Cloud temperature
• Wind patterns (which can displace clouds)
• Accuracy of timing and location of seeding

The WMO recommends that all cloud seeding projects be designed as scientific experiments with control groups for comparison and clear quantitative monitoring. Many reported successes are difficult to verify due to the inherent variability of natural weather.

Potential and Limitations: Cloud seeding is presented as a promising technology that allows humans to partially influence weather, especially in the context of climate change. However, it is emphasized that it can only support nature, not replace its fundamental laws.

2. History and Development

The concept of cloud seeding dates back to the mid-20th century, with a history of experimentation and application in both civilian and military contexts.

• 1946: Physicist Vincent J. Sheffer conducted the first cloud seeding experiment by releasing dry ice into a supercooled cloud, observing the formation of ice crystals and snow. This marked a significant step towards active weather modification.
• Post-1946: Colleagues identified silver iodide as an ideal ice-nucleating agent, leading to its widespread use in subsequent experiments.
• From 1960s: Governments and meteorological organizations increased research funding. In the US, Project Skywater aimed to increase water resources in arid states through aerial and rocket seeding.
• Military Applications: Cloud seeding was also deployed for military purposes. The Operation Popeye (1967-1972) by the US in Vietnam aimed to induce prolonged rainfall over the Trường Sơn mountain range to disrupt the Ho Chi Minh Trail.
• Late 20th/Early 21st Century: Cloud seeding entered a phase of larger-scale application and experimentation.
  • China: Invested heavily in a vast cloud seeding network, using rockets to disperse AGI and employing radar and monitoring systems for weather coordination.
  • United Arab Emirates (UAE): Invested hundreds of millions of dollars in artificial rainmaking to combat drought, even using drones to emit radio waves into clouds to stimulate rain.
  • United States: States like California, Idaho, and Wyoming continue winter cloud seeding programs to enhance snowpack in mountainous regions, crucial for dry season water supply.
• Modern Advancements: Researchers are experimenting with nano-materials for AGI and using supercomputers for simulations to optimize seeding parameters (timing, wind, altitude). Newer nano-AGI or modified structures aim for faster and more efficient ice nucleation.

The evolution from simple dry ice experiments to sophisticated material science and computational modeling highlights the progress in cloud seeding, yet scientists consistently stress that its effectiveness is never 100% certain and requires transparent, cautious evaluation.

3. Principles of Operation

Cloud seeding operates on the principle of providing "seeds" for precipitation formation within clouds.

Two Primary Methods:

• Glaciogenic Seeding (Reo mây lạnh):

  • Target: Clouds with temperatures between -20°C and -7°C.
  • Agents: Silver iodide or propane.
  • Mechanism: The crystalline structure of AGI mimics ice. When introduced into supercooled clouds, it triggers the formation of millions of tiny ice crystals. As these crystals grow heavy enough, they fall as snow or rain.
  • Application: Common in cold climates or high-altitude mountainous regions.

• Hygroscopic Seeding (Reo mây ấm):

  • Target: Clouds with temperatures above 0°C.
  • Agents: Sodium chloride (salt), which is highly hygroscopic (attracts water).
  • Mechanism: Salt particles absorb surrounding water vapor, causing small water droplets to coalesce into larger ones that can then fall as rain.

Delivery Methods:

1. Aircraft: Planes carry dispensers of silver iodide, salt, or dry ice. Pilots release these agents at precise locations, altitudes, and times. This is the most common and controllable method.
2. Rockets or Artillery: Used for seeding clouds at higher altitudes or in mountainous areas where aircraft access is difficult. Rockets or shells carry seeding agents and disperse them upon reaching a certain altitude.
3. Ground-Based Generators: These devices burn compounds containing AGI or salt, creating a plume of particles that are carried upwards by wind into the clouds. This method is cheaper but less controllable due to wind variability, often resulting in lower effectiveness.

Quantifiable Impact: Studies suggest cloud seeding can increase precipitation by 5% to 30%, depending on weather conditions. However, failures can occur if factors like wind, humidity, or cloud structure change rapidly.

4. Countries Utilizing Cloud Seeding

Several nations have actively implemented cloud seeding programs for various purposes.

• China:

  • Possesses the world's largest weather modification network.
  • Uses cloud seeding for drought relief and to ensure clear skies for major events.
  • 2008 Beijing Olympics: Dispersed silver iodide and salt via rockets to clear rain clouds before the opening ceremony.
  • 2020 Plan: Aimed to expand weather modification systems to cover over 5.5 million km² by 2025 to increase rain and reduce hail/drought.
  • 100th Anniversary of the Communist Party (2021): Conducted a two-hour artificial rainmaking campaign using rockets to disperse AGI in mountainous areas, aiming to induce rain, wash away fine dust, and reduce PM2.5 levels.

• United Arab Emirates (UAE):

  • A regional leader in cloud seeding, particularly due to its arid climate and strategic focus on water security.
  • Employs specialized aircraft and radar systems for seeding, adapting approaches to desert conditions.
  • Views cloud seeding as a national strategic initiative for water augmentation, technological advancement, and international cooperation.

• United States:

  • Western states with arid climates heavily rely on snowpack and snowmelt for water.
  • Cloud seeding is a supplementary tool for water resources.
  • Colorado River District: Estimates cloud seeding can increase snowpack by up to 15% from a storm, potentially adding 98 million m³ of water annually (enough for ~160,000 households).
  • Idaho: Uses aircraft and rockets to seed clouds with silver iodide in mountainous regions to increase snowfall, aiming to improve water security and mitigate drought.
  • Wyoming: Research in the Sierra Madre and Medicine Bow ranges has shown 5-15% increases in precipitation under ideal conditions.
  • California: Historical projects report increases of 1.5% to 8.8%, with significant uncertainty.

• Russia:

  • Utilizes cloud seeding primarily for ensuring clear skies during major public holidays.
  • Victory Day (May 9th) in Moscow: Employs aircraft to disperse chemicals (silver iodide, liquid nitrogen, cement powder) to induce rain in suburban areas before clouds reach the city center, ensuring clear skies for parades.
  • An estimated 430 million rubles (approx. $6.5 million) is spent annually for this purpose.

5. Cloud Seeding in Vietnam

Vietnam has a history of experimenting with artificial rainmaking, though its widespread application remains debated.

• Early Experiments (Late 1950s):

  • Around 1959, with assistance from Chinese experts, Vietnamese meteorologists used aircraft to disperse salt into clouds over the Red River Delta (Hải Dương and Hưng Yên provinces).
  • Tests on AN2 aircraft showed rain, with measured rainfall in the test area reaching 40-60 mm.
  • However, the experiments lacked comprehensive measurement and verification systems to definitively confirm the extent of increased rainfall.

• Later Proposals and Research (Late 1990s - Early 2000s):

  • 1998: The Institute of Meteorology, Hydrology and Climate Change initiated a project to assess the feasibility of artificial rainmaking in the Central Highlands, evaluating cloud conditions and technological requirements.
  • 2007: A research team led by Associate Professor Vu Thanh Ca studied the scientific and technical basis for artificial rainmaking in Vietnam, estimating the cost of trials in the Northern Delta and midland regions at $5.1 million to $7 million. They concluded Vietnam had the potential for trials but needed to develop suitable technologies.

• Economic Viability Concerns (2016 onwards):

  • Despite surveys and proposals, domestic media in 2016 reported that artificial rainmaking was not yet an economically viable solution due to high costs, the need for suitable technology, and unproven effectiveness.
  • Some opinions suggested that while Vietnam could potentially conduct artificial rainmaking, its economic benefits were negligible. During dry weather with stable atmospheric conditions, thin or absent clouds make artificial rain extremely difficult.

• The September 2nd, 2025 Rumors:

  • Leading up to Vietnam's National Day on September 2nd, 2025, social media buzzed with claims that Russia had assisted Vietnam in "chasing away clouds" to ensure clear skies in Hanoi, citing systems worth millions of dollars and even attributing orders to Putin.
  • These claims, often accompanied by unverified videos and images, gained significant traction.
  • Official Rebuttals: No official confirmation from Vietnamese mainstream media, government agencies, or meteorological bodies supported these claims. Conversely, state media published scientific explanations emphasizing that artificial rainmaking is not a magical trick and its effectiveness is highly dependent on cloud conditions, wind, and humidity, requiring transparent, quantitative evidence before widespread application. A People's Newspaper analysis on September 2nd, 2025, urged public caution regarding these rumors.

6. Debates Surrounding Cloud Seeding

The potential and challenges of cloud seeding are subjects of ongoing debate.

Potential:

• Limited but Measurable Impact: Meteorological experts acknowledge that cloud seeding can yield certain results, but effectiveness is highly dependent on specific natural conditions. The WMO confirms physical and statistical evidence of increased rain or snow in some contexts, but not universally.
• Rigorous Design Needed: Cloud seeding projects require strict design, control groups, and independent monitoring.
• Modern Experiments: Contemporary experiments, like the Snowe trials in Idaho (2017), using radar and rain gauges, have detected measurable increases in snow formation due to AGI seeding in supercooled clouds, albeit in millimeters and with limited impact per storm.
• Seasonal/Regional Assessments: US state reports (e.g., Wyoming, California) often cite increases ranging from a few percent to under 10% under favorable conditions.

Challenges:

• Environmental and Health Concerns:
  • Silver Iodide Residue: Excessive use of AGI can lead to its accumulation in soil and water. While considered safe at low concentrations, long-term buildup may affect aquatic life and food chains. Some experts warn of potential impacts on microbial composition and ecosystems.
• Extreme Weather Risks:
  • Unintended Consequences: Inducing rain in one area could lead to excessive water, causing floods, landslides, or agricultural damage if not controlled.
  • Downwind Effects: Areas downwind might experience reduced natural rainfall, leading to localized drought or water resource conflicts.
  • Chongqing Incident (2024): A failed attempt to create rain and snow in Chongqing during a heatwave, resulting in snow falling in the city, was attributed by some to "Downdraft Impact," an indirect consequence of cloud seeding.
• Technological Dependence:
  • Reduced Investment in Natural Water Management: Reliance on cloud seeding might lead some nations to cut investments in natural water resource management, making them vulnerable if the technology fails.
  • Limited Effectiveness: The US GAO (2024) warned that cloud seeding only provides small increases (0-10%) and its true effectiveness is hard to measure.
• Ethical and Equity Issues:
  • Unequal Access: Wealthier regions can afford cloud seeding for their benefit, potentially creating disparities in water resources and agricultural outcomes compared to less affluent neighboring areas. This can lead to water scarcity, crop failure, and environmental inequality.
• Attribution and Misinformation:
  • False Attribution: People tend to attribute heavy rainfall events to cloud seeding, even when natural factors are the primary cause.
  • UAE Floods (April 2024): Widespread social media claims linked record rainfall and flooding in the UAE to excessive cloud seeding. However, meteorological agencies and independent scientists refuted this, attributing the event to a powerful weather system amplified by warming climate and urbanization. Radar data showed no seeding flights in the storm's core, and experts stated cloud seeding lacks the capacity to create such extreme events.
• International Disputes and Governance:
  • China's Expansion Plans: China's ambitious plan to cover over 5.5 million km² with weather modification by 2025 raises concerns among neighboring countries about transboundary impacts on climate, agriculture, and water resources.
  • Call for International Regulations: There is a growing demand for stricter international regulations to ensure cloud seeding is used transparently, controllably, and for the common good, rather than as a tool for competition or conflict.

The video concludes by hoping viewers enjoyed the content and encourages engagement.