Eideard

Bravo, Tim…

Thousands of pro-independence Basque citizens march in the rain in San Sebastián, northern Spain, to demand the freedom of Arnaldo Otegi, the former leader of outlawed Basque independence party Batasuna who was sentenced on 16 September to 10 years in jail.

I went looking for photos of the demonstration; but, my eye was caught by all the umbrellas. In Seattle or Boston, even in London or Glasgow, you wouldn’t see so many umbrellas in a rainy demonstration.

I haven’t the slightest explanation for the preference. It rings no responsive chord in these Celtic genes.

 
The Jemez Mountains are just out of sight beyond the mesa, the Caja del Rio.

Late morning monsoon breezes start to sprout thunderheads over the Jemez and hopefully they will drift this way and rain on Lot 4.

A secret £7 million weather project in Abu Dhabi has resulted in dozens of man-made rainstorms…

Scientists employed by Sheikh Khalifa bin Zayed Al Nahyan, president of the UAE and leader of Abu Dhabi, successfully created more than 50 rainstorms in the state’s Al Ain region last year, mostly in July and August when there is virtually no rain at all. It is believed to be the first time the system has produced rain from clear skies.

They have been using giant ionisers, shaped like giant lampshades, to generate fields of negatively charged particles, which create cloud formation.

In a company video, seen by The Sunday Times, Helmut Fluhrer, the founder of Metro Systems International, the Swiss company in charge of the project, said: “We are currently operating our innovative rainfall enhancement technology, Weathertec, in the region of Al Ain in Abu Dhabid. We started in June 2010 and have achieved a number of rainfalls.”

Bet it works better than Navajo rain dances.

Guatemalan soldiers carry 1 of 3 coffins – part of a group of 72 migrants killed in Mexico
Daylife/Reuters Pictures used by permission

As turboprop and jet aircraft climb or descend under certain atmospheric conditions, they can inadvertently seed mid-level clouds and cause narrow bands of snow or rain to develop and fall to the ground, new research finds.

Through this seeding process, they leave behind odd-shaped holes or channels in the clouds, which have long fascinated the public.

The key ingredient for developing these holes in the clouds: water droplets at subfreezing temperatures, below about 5 degrees Fahrenheit (-15 degrees Celsius). As air is cooled behind aircraft propellers or over jet wings, the water droplets freeze and drop toward Earth.

“Any time aircraft fly through these specific conditions, they are altering the clouds in a way that can result in enhanced precipitation nearby,” says Andrew Heymsfield, a scientist with the National Center for Atmospheric Research (NCAR) and lead author of a new study into the phenomenon.

“Just by flying an airplane through these clouds, you could produce as much precipitation as with seeding materials along the same path in the cloud…”

As far back as the 1940s, scientists have wondered about the causes of these clouds with gaps seemingly made by a giant hole punch. Researchers have proposed a number of possible aviation-related causes, from acoustic shock waves produced by jets, to local warming of the air along a jet’s path, to the formation of ice along jet contrails.

Indeed, the earliest observations implicated jet aircraft, but not propeller aircraft, as producing the holes.

Researchers in the 1980s observed that propeller aircraft could transform supercooled droplets into ice crystals, and experiments were launched in the 1990s to characterize the phenomenon.

RTFA – for the tale of how one group of researchers had the data they needed to understand this process – fall into their laps.

First monsoon of the season coming in over the Caja del Rio. Moisture from Mexico and from California.

As always, we can use it.