Go away Irene!

Weather control systems have been subject to bold claims of late, but a new technology may offer more hope… although it probably won’t stop a hurricane.

As the $10bn clean-up of the East coast of America begins in the wake of Hurricane Irene, it was perhaps most sobering to reflect how defenceless New York was.  

Hurricanes rarely strike the great city, but when they do they show no regard for its exalted status as the ‘capital of the Western World,’ and seat of commercial power. The swirling white mass that looks so innocuous on satellite images is in fact an immovable force that we have no power or technology to stop. With the evacuations it seemed the only solution was to run.

‘Go away Irene!’ read the graffiti on one of the boarded up shops in Manhattan. If only it were that simple. But this is Friday Futurescope and, therefore, a forum to ask whether the seemingly impossible could ever be achieved. 

I think it’s fair to say Hurricane mitigation technology is - and will remain - in the domain of science fiction for the foreseeable future. But there have been some interesting developments in the field of weather control in recent years.

(At this point I should probably make a clear the distinction between weather control and geoengineering, which aims to modify long-term climate patterns and the subject of an earlier blog).

Seeding

The Chinese Government has invested perhaps more heavily than any other nation in so-called cloud seeding in response to years of continuing drought in its Northern provinces. 

It is a technology that can be traced back to research by General Electric in 1946 but the approach basically involves aircraft or artillery spray of silver iodide into clouds to encourage tiny vapour droplets to coalesce.

The Chinese make some bold claims about the benefits of clouds seeding, to the extent where neighbouring regions have angrily accused each other of ‘stealing rain’ using cloud seeding. But from an evidence-based, scientific perspective it’s actually very difficult to prove causality with cloud seeding - the question essentially is ‘would it have rained anyway?’

Plus the silver iodide isn’t great to have hanging around and a cloud must already exist before scientists can seed the atmosphere - what if want rain from blue skies?

It seems one nation’s unbridled growth and unquenchable thirst may have surpassed that of the Chinese in the weather controlling stakes.

Storms

Earlier this year reports surfaced of a project in the United Arab Emirates claiming to have created rain storms in the Al Ain region of Abu Dhabi when weather reports predicted an extremely low probability of clouds or rain.

The technology, backed by Swiss company Metro Systems International employs huge ionizers shaped like lampshades mounted on steel poles in an effort to generate fields of negatively charged particles.

These electrons attach to specks of dust (ubiquitous in the desert-regions) which are these are then carried up from the emitters by convection currents. Once the dust particles reach the right height for cloud formation, the charges will attract water molecules floating in the air which then start to condense around them.

Crucially though there must be sufficient moisture in the air, around 30 per cent humidity or more, to form clouds and ultimately rain.

Apparently, Metro Systems built five ionising sites each with 20 emitters capable of sending trillions of ions into the atmosphere. The system was tested for four summer months with the emitters being switched on when operating conditions were reached, resulting in a claimed 52 rainstorms.

Again though, while the reports seem compelling it’s difficult to prove causality beyond reasonable doubt. It’s not unheard of for storms to seemingly materialize from nowhere as hot air rises from the coastal areas in the UAE.

Lasers

Now a new approach claims to illicit a greater level of control over precipitation than either seeding or ionization, using that seemingly ‘cure-all’ technology of lasers.

A study published in the journal Nature Communications this week documents the efforts of a team from Geneva University who aimed a mobile femtosecond-terawatt laser system the size of a garage up at an area of the atmosphere near the Rhône River.

The idea was to create to create nitric acid particles in the air to which moisture will gravitate forming droplets. They fired the laser pulses when the humidity was over 70 per cent for a total of 113 hours.

Sampling aerosols alternately at 2cm distances from the firing zones, they observed a step-wise formation of nitric acid particles with the resultant coalescence of water drops.

These droplets of water were on the order of a few microns in size and therefore too small to form rain - but crucially they could demonstrably prove, with a reasonable degree of certainly, that it was a result of their efforts. Plus it tallied with lab results obtained a year previously.

Jérôme Kasparian the physicist who led the team, is confident that with modifications, the system will reliably and consistently be able to form rain.

But perhaps more tantalizing, he says the technology could be used to halt an imminent downpour in its tracks by creating so many tiny droplets in the air that none can grow large enough to precipitate. ‘Maybe one day this could be a way to attenuate the monsoon or reduce flooding in certain areas,’ Kasparian told the Guardian.

So perhaps the prospect of Hurricane control is not so far beyond our grasp after all?

‘From a technical point of view, sweeping the laser is not an issue. They do it in nightclubs all the time,’ Kasparian said.

Clearly we have nothing to worry about with this man leading the technological charge.

If you’d like to hear him speak in person there’s a conference at the end of the month at Geneva University titled ‘Laser-based Weather Control’.