London, May 3: Physicists claim to have found a better way to trigger rain on demand — using lasers to create small clouds.
And, after generating clouds in the laboratory, they have tried it in the skies over Germany.
People have experimented with cloud seeding for long in the hope of boosting rainfall, usually by sprinkling silver iodide crystals into clouds high in the atmosphere. These crystals encourage large water droplets to form around them, and the droplets then fall as rain— in theory, at least. Now, a Swiss team has found that lasers could be a be a way to call down rain when it’s needed.
“The efficiency of this technique is controversial,” the New Scientist quoted Jérôme Kasparian at the University of Geneva, who led the research team which created the clouds, was quoted as saying.
In fact, the team has reported the first successful use of this technique to summon clouds from air both in the laboratory and in the skies over Berlin. In the lab, the team fired extremely short pulses of infrared laser light into a chamber of water-saturated air at -24 °C. Linear clouds could be seen to form in the laser’s wake, like a miniature aeroplane contrail. According to Mr Kasparian, the laser pulses generate clouds by stripping electrons from atoms in air which actually encourage the formation of hydroxyl radicals. Those convert sulphur and nitrogen dioxides in air into particles that act as seeds to grow water droplets. —PTI
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Jordan river is likely to die by 2011
Alumot (Israel), May 3: The once mighty Jordan river, where Christians believe Jesus was baptised, is now little more than a polluted stream that could die next year unless the decay is halted, environmentalists said on Monday.
The famed river “has been reduced to a trickle south of the Sea of Galilee, devastated by overexploitation, pollution and lack of regional management,” Friends of the Earth, Middle East said in a report. More than 98 per cent of the river’s flow has been diverted by Israel, Syria and Jordan over the years. “The remaining flow consists primarily of sewage, fish pond water, agricultural run-off and saline water,” the environmentalists from Israel, Jordan and the West Bank said in the report to be presented in Amman on Monday. “Without concrete action, the lower Jordan River is expected to run dry at the end of 2011.”