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Soaring the glory

It's early morning in the Gulf Country and a great rolling mass of cloud is rapidly approaching. For the aborigines the arrival of the Morning Glory signified abundant birdlife to follow. For a growing group of extreme gliders it's the key to an indescribable experience.

It's late August, and it's 4 am inside the front bar of the only pub in Burketown, a tiny town over 400km north of Mt Isa in far north Queensland.

Droplets of water are forming on the beer fridge. They fatten up and slide downwards, joining up with others and gathering momentum. In Burketown, the locals say this saturating humidity is a sure sign of things to come.

Outside the pub, something weird is happening in the sky. Moments before, the atmosphere had been perfectly still. Now a sudden gust comes rushing out of nowhere at 40km/hr, catching up a beer can and sending it spinning across the road.

Overhead, the moonlight glints on something incredibly huge. A vast dark mass is rapidly approaching from the north easterly horizon, a great, boiling, rolling pile of cloud like a gigantic combine-harvester, headed straight for town.

If anyone was in the bar this early, they would see photos of this same, enormous cloud formation adorning the walls of the pub, wedged in among the mounted fish heads, crocodile jaws and boomerangs of this tropical outpost. It's obviously not the cloud's first visit.

Over at the Burketown airstrip, there's a soft rustle and movement as dark figures prepare for what may be the experience of their life. They have made the arduous journey to Burketown from their distant lives in other states and countries, for just one purpose: to ride the Glory.

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Good omen

From around August until November the Morning Glory is one of the most spectacular events in nature to be found anywhere in Australia. Because of its remote location - in the Gulf of Carpentaria (the pointy cone-shaped mass of land that protrudes from northern Australia) where only a handful of people live - it is less well known than Kakadu lightning storms and other spectacular weather phenomena of Australia.

To the Aboriginal people of the area, the Morning Glory is a good omen of abundant birdlife to follow. And sure enough, as the last of these stratospheric blockbusters roll across the Gulf late in the year, the first rains of the wet season begin.

The Morning Glory is essentially a gigantic cloud that moves in one direction with the relentless motion of a huge combine harvester that appears to be rotating backwards. In length it can stretch over 1000km from end to end - the distance from Sydney to Melbourne - and travel at speeds up to 60km/hr. The cloud itself can be as tall as one kilometre from bottom to top.

Cloud is continuously created in the updraught along the leading edge, as moist air from near the surface is raised up to an altitude where it condenses. As the air in the cloud rolls backwards over the trailing edge, the cloud elements are eroded away as the air descends and warms.

It is this unique motion that first caught the attention of the gliding community. Indeed, for the past decade or so, a handful of brave - some would say crazy - people have come to Burketown to 'surf' or 'soar' these massive cloud-waves. Perched inside tiny fragile motor gliders and hang gliders with their engines turned off, these thrill-seekers willingly expose themselves and their craft to forces which could crush them to fragments in an instant. Some have achieved speeds of up to 150km/hr without the use of the motor, poised at the leading edge of the Glory to catch updraughts which can thrust them 3000 metres up into the sky.

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First flight

One of the first to soar the Glory was Byron Bay pilot Russell White. Soaring is a term used by glider pilots to describe flying without the use of an engine. Russell had heard about the Glory for years, but says his appetite was truly whetted in 1989 when a Belgian friend who'd travelled to the area described seeing "an amazing roll cloud stretching from horizon to horizon, churning in from the Gulf at dawn".

"We'd seen photos and had pipe-dreamed about flying this fantastic phenomena," he recalls. Russell and flying partner Rob Thompson flew their motor glider (a type of long winged glider with an engine at the front) all the way to Burketown the next day to see if they could catch a Morning Glory. After a tough trip over endless flood plains without the help of instruments, they were introduced to a local fisherman who knew all about the Morning Glory. "You'll know when it's coming", he told them, "if there's a heavy dew in the morning, the Glory'll come". Humidity equals dew, hence the sweating beer fridge.

After accidentally sleeping in the next morning, they made a scramble to get to the airport. "We lined up on the runway, just as the cloud rolled overhead, very low, eclipsing the sunshine as it went. We caught it halfway down the strip, the windsock still indicating nil wind, turned low and faced this great, grey Chiko Roll at 400 feet," Russell says.

Rapidly they ascended to 330 metres, and suddenly they were at the front of the cloud, moving up quickly. It was at this moment that they killed the engine. "The silence was eerie as we continued to rise, awestruck by the spectacle. It was truly a magic moment."

They rode the cloud inland until it petered out, then turned tail and headed back to Burketown, thrilled and amazed at what they had achieved. A few years later, Russell returned to do it all again and to his delight, reached speeds of 150km/hr, unofficially breaking several world records.

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Birth of a glory

One of the first people to recognise how the Morning Glory formed was Dr Doug Christie of the Australian National University (ANU), who was with Russell White in his glider when those incredible speeds were achieved.

Back in 1975 Doug was examining data from an array of ultra-sensitive microbarometers which had been set up by the ANU across the arid interior of the Northern Territory. The equipment was there to detect infrasonic waves - exceedingly low frequency sound waves that can travel thousands of kilometres, and can be used to detect the carrying out of clandestine nuclear weapons testing.

Quite unexpectedly, Doug noticed a new type of atmospheric wave showing up in the data: a large amplitude, slow moving, solitary wave. He realised these exotic gravity wave disturbances were probably closely related to the then barely understood Morning Glory phenomenon of the Gulf of Carpentaria.

He built a portable array of microbarometers and used them between 1980-1996 to further understand the Morning Glory, confirming that these giant rolling clouds were large amplitude solitary waves that can manifest in several different forms.

Doug says that although atmospheric waves are common throughout the world, those in the Gulf are unique because they are often accompanied by a spectacular, visible, rolling cloud formation that appears regularly during a particular time of the year.

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Breakers on a beach

Morning Glories are an extreme example of a travelling wave-cloud system - a single ridge of air that moves without changing pace or shape. There are three kinds of Morning Glory - those which come from the north east, those from the south east and those which move up from the south. About half of all Glories are the north-easterly type, with up to 10 evenly spaced Glories rolling across the sea and over the land like enormous breakers on a beach.

The story of how Glories form begins much further to the north, over the vast Cape York Peninsula. In less than 24 hours, sea air moving in over Cape York Peninsula will build up to such a height that it tumbles over westward, setting up pressure or gravity waves which reverberate right through the Gulf.

The first trigger for a Morning Glory is when the massive land surface of Cape York warms up during the day, in turn warming the air above it. This warmed air rises, sucking sea breezes in across the land from either side of the peninsula. Around midnight, these currents of air collide above the middle of the Peninsula, and shoot upwards, building up a mountain of cold and turbulent air. Eventually in the early hours of the morning this mountain of air falls over and is pushed westwards by the prevailing winds.

Pretty soon, this cold air collides with the stable boundary of sea air and produces a series of massive atmospheric shockwaves which travel west like ripples on a pond. The air at the front of this travelling shockwave is forced upwards, cooling and condensing into a cloud, which then dissolves and disappears at the rear of the wave as it sinks down.

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Wind shear danger

Morning Glories are accompanied by a strong wind shear which can be dangerous to planes, especially during take-off and landing. As a result of earlier research by Doug Christie and others, pilots are now very much aware of the dangers of wind-shear. Modern aircraft also have more powerful engines that can help pilots recover from an encounter with an unexpected wind shear. Knowing about the nature of solitary waves has helped pilots train to recognise and avoid the wind-shear generated by these mysterious solitary waves.

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Soaring

As more people learn about the challenges of the Glory, the tiny outpost of Burketown may become a Mecca for some of the bravest flyers in the world. But although the word is spreading, the remoteness of the location means that there are still perhaps only 20 craft which make the journey to soar the Glory each year.

Russell White has been every year since that first flight in 1989 and doesn't look like stopping. "Trying to describe the Morning Glory, I'm lost for words," he says. "It's a bit like seeing Ayers Rock or any of the wonders of the world. The proportions are absolutely immense. You can't explain just how fantastic it is."

And he doesn't want to keep the experience to himself. "Soaring is very much the king of sports, so I think anything to promote it is worthwhile."

But if you do plan to visit Burketown and fly the Glory, just make sure you pop in to the pub and check out the beer fridge first.

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Further info and credits

Aerial video of the Glory

Science of the Glory

A guide to the Morning Glory clouds and the Gulf of Carpentaria

Burketown images

Morning Glory Roll Cloud Flying

Special thanks to:

Morning Glory soarers Russell White and Frank Fontyne

Dr Doug Christie, University of Sydney

Dr Jorg Hacker - Airborne Research Australia, Flinders University

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