Last weekend's celebrations and summits marking the 300th anniversary of St. Petersburg went off without a hitch. Russian President Vladimir Putin succeeded in showing off his hometown and the country's most beautiful city, in all its restored glory, to more than 40 world leaders. At one point, rain threatened to spoil the party, but the clouds soon receded -- seemingly by miracle. Or was it? RFE/RL reports from St. Petersburg on Russia's "cloud-busters."
Voeikovo, Russia; 3 June 2003 (RFE/RL) -- Since time immemorial, man has prayed to the heavens for rain to fall or invoked the same spirits to make it stop.
But in the Soviet Union, they didn't believe in God. Scientists had more practical ideas. First encouraged by ruler Josef Stalin in the late 1940s, Soviet meteorologists began experimenting with various ways to influence the shape and size of clouds.
A few years earlier, scientists in the United States had demonstrated that what they called "cloud-seeding" -- in effect dispersing dry ice or other chemicals such as silver iodide into the atmosphere -- could induce premature rainfall. Americans continued to experiment with the idea but it was the Soviets who made the technology their own and took it to unsurpassed levels.
Today, Russia is the leading "weather-making" power in the world. It doesn't usually rain on Russian parades. And there's a reason.
Men like Georgii Shchukin, deputy director of the Voeikov Geophysical Observatory Research Center for Atmospheric Remote Sensing, make it their business to chase the clouds away.
They do it by using aerial seeding to induce clouds to shed their rain before they reach a designated "dry" destination, such as a parade ground.
Cloud seeding works on a simple principle. Before it produces rain, a cloud is made up of millions of tiny water droplets that are too small to form raindrops. Sending aircraft to disperse dry ice or other substances into those clouds cools them, inducing rapid condensation, which causes rain.
It is, its practitioners say, environmentally harmless. The technique has been used experimentally in several countries to water crops or even to help extinguish small-scale forest fires.
The theory is simple. But its realization is far trickier. "Modifying the weather is an art," Shchukin explained. "You have to have very good teachers, very good schooling. We haven't reached a level where you can take anyone and have them push a button. No. You have to analyze the state of the clouds from all points of view. There are many simultaneous processes taking place: condensation, chemical and other movements, and a lot depends on the aerial terrain."
This past weekend (31 May-1 June), the Voeikov Observatory got orders from the Kremlin to ensure dry weather during festivities marking the 300th anniversary of the city of St. Petersburg. President Vladimir Putin would be hosting more than 40 world leaders in Russia's former imperial capital and many outdoor events, including a laser show and fireworks, were planned.
The observatory sprang into action. With two meteorological tracking stations in the area, one in downtown St. Petersburg and the other in the village of Voeikovo 20 kilometers outside the city, Shchukin and his staff were ideally positioned to coordinate the rain-control effort. Years of practice in what is one of Russia's wettest regions have made Shchukin's team adept at identifying and "modifying" rain-laden cloud formations on demand.
Using up-to-the-minute meteorological data, the Voeikov Observatory provided pinpoint cloud data to a fleet of airplanes flying in 60-kilometer circles above the Gulf of Finland. Moscow-based cloud-seeders also joined in the effort.
"Several organizations that hold licenses to 'seed' clouds with the aim of regulating precipitation, took part in the work. The Moscow-based Agency for Atmosphere Technologies participated, as well as others. In total, 10 aircraft were used," Shchukin said.
Shchukin's team faced their first challenge on the afternoon of 31 May, as a fast-moving front closed in from Finland, threatening to soak the first evening's celebrations. Aleksandr Shapovalov, head of the meteorological laboratory at the Voeikov Observatory, points to a computer screen that illustrates that day's radar satellite imagery. "Look, you can see that from the West a cloud system appeared and it was causing rain showers," he said. "When it was far away, you couldn't detect the showers, but planes working in the region were already reporting rain and they began seeding the clouds at that moment, at 4 p.m. Now look, as a result of this action, the cloud system began to break up and at 4:22 it broke into two fragments. Later, you can see the effect even more clearly."
Indeed, the computer imagery shows a light-blue mass blowing in from the Gulf of Finland, growing in size and darkness as it heads for St. Petersburg. But when the mass reaches a certain point, it breaks into two halves, leaving a clear space in the middle, as one part drifts north and another south, turning green -- the color of rain on the radar screen. The clear space appears to correlate precisely with the location of cloud-seeding aircraft at the time.
The mostly clear spot, meanwhile, drifts over the city. Shapovalov said if it hadn't been for gaps in the cloud-seeding effort, to allow VIP aircraft to land at St. Petersburg's airport, the city could have been spared any rain. As it turned out, St. Petersburg got a mild shower -- 10 times less rain than originally forecast, while areas to the north and south of the city got soaked.
"If cloud seeding had taken place nonstop, we would have had a fully clear strip. But because during some periods the cloud-seeding planes couldn't do their work, there were a few shower spots. Look, here it's very clear. There is rain -- the green parts are rain. There is rain here while over the city, skies are clear," Shapovalov said.
Shapovalov describes as pointless the ongoing debate in many countries about whether cloud seeding really works. To him, data from this weekend's work 5,000 meters above the Gulf of Finland offer conclusive proof that it does.
"Scientists and meteorologists have long debated the effectiveness of cloud seeding. But in this case, cloud seeding that was done to meteorologically defend the city during the celebrations demonstrates that there was an effect, an obvious effect," he said.
The Kremlin seems to think so, too. President Putin's staffers have sent a message of thanks to the St. Petersburg cloud-seeders, who, in turn, are hoping for the funds they were promised. While refusing to put a figure on the whole operation, rain making, Georgii Shchukin said, doesn't come cheap.