Wednesday, August 29, 2012

Waterspout Whips in the Adriatic Sea

The atmosphere crackles with electricity, the air is close, and in the distance a towering column of rotating air and water approaches. Such a sight might be enough to scare the wits out of some people, but for Mladen Duka, the photographer who took these awe-inspiring photos, the thrill of the situation overcame any fear. Just. A fast retreat was still in order. “Who could think that an ordinary morning walk from Bol to Murvica, two small villages on island of Brach, Croatia, would be so exciting?” he wonders.

Exciting indeed! Many people go their entire lives without ever witnessing a waterspout – one of nature’s most spectacular weather phenomena. Even fewer individuals manage to capture a photo of what they saw. Fortunately for us, Mladen Duka photographed an entire sequence of a waterspout’s impressive yet ominous advance over the Adriatic Sea.

Here, we see the waterspout while it is still some distance away. It curves down from the mass of clouds overhead like a giant elephant’s trunk reaching into the water for a drink. It was a sight Duka and his walking companion certainly weren’t expecting to see that day.

“It was August 4, 2006 and the waterspout appeared between [the] islands of Hvar and Brach, just in front of Murvica beach,” Duka explains. “It was fascinating: she [the tornado] was there in front of me and my friend, connecting the sea and the clouds.”

It’s not unusual for waterspouts to be accompanied by thunder and lightning – forks of which spectacularly accompanied this particular weather event, beautifully shown in the first image of the sequence. That said, this photo suggests that it wasn't actually a particularly stormy day. The trees don’t seem to be being blown about much by wind, and the sea, although a little choppy, still looks relatively smooth. The sky even looks a little bit blue on the horizon!

Waterspouts can be classified as either ‘fair weather’ or ‘tornadic’, depending largely on the weather conditions in which they arise. Fair weather waterspouts can materialize on sunny, calm days and don’t tend to move around all that much. The more violent – and dangerous – tornadic waterspouts invariably appear in the midst of serious thunderstorms.

Looking at the dark clouds in this picture, we might jump to the conclusion that this waterspout is of the tornadic variety. However, as Duka explains (and the previous photograph illustrates), the weather was fine and still as the waterspout approached. “All around us was calm, windless, and we just heard the loud crickets sizzle and waterspout fizzle,” says Duka, describing the event (quite poetically, we think!).

Flashes of lightning notwithstanding, the relatively peaceful weather conditions in which this waterspout appeared suggest that it was of the fair weather type. Fair weather tornadoes commonly occur around coastal areas like this, and while they are generally less dangerous than their more violent tornadic counterparts, it’s still a good idea to keep out of their way. If they move onshore, they usually fizzle out pretty quickly, but can some waterspouts can damage property and leave people injured when they make landfall.

Here’s a closer view of this waterspout. You can see that the bottom of the funnel-shaped cloud isn’t quite touching the ocean. This may be related to the fact that waterspouts, despite their appearance from a distance, don’t really suck up water. In fact, it’s more accurate to think of them as forming in the sky and reaching down towards the water’s surface, rather than rising out of the ocean. The white coloration we can see is actually spinning droplets of condensed water – the same kind of moisture that makes up clouds.

Although water is not being sucked up into the clouds in the way a drink is sucked up through a straw, a waterspout’s winds do cause the waters to swirl and rise up some way into the air, as we can see around the base of this example. Forming prior to the funnel itself, this sea spray is called the ‘cascade’.

As the spinning funnel of air and mist approaches, we’re given an even closer picture of the eddying cascade at its base. As with land tornadoes, a waterspout’s central vortex and the rotating updrafts that surround it can lift water and even objects or animals – like unfortunate fish – up into the air. And given that what goes up must come down, when the waterspout subsides, everything it may have lifted up into the sky will be dropped back down to earth.

Waterspouts have picked up, carried and then dropped some unusual items in the past. For example, Montreal once experienced raining lizards, New York has been hit by showers of tadpoles, and in France there was even a torrent of toads – all bizarre events that have been attributed to waterspouts. We certainly wouldn’t want to be caught without an umbrella in such weather!

Bringing us back to Earth – and the presence of this particular waterspout – Mladen says: “She was coming closer and closer in full strength and beauty, swinging [at] the waist,” conjuring a peculiarly apt image of a colossal woman with a swaying gait. “We stood there, taking pictures, and finally when [the] lightning start to stroke all around, we start[ed] to run to shelter in a small chapel at the nearby graveyard.”

Should you ever see a waterspout approaching, heading for shelter is a wise idea. And if you can’t find cover, remember to move in a direction perpendicular (at 90-degree angle) to the path of the oncoming funnel. Finally, keep a safe distance when taking pictures. After all, there’s not much point in having mementos if you’re not around to admire them.

From this picture, you can get an idea of just how thrilling (or terrifying, depending on your point of view!) a waterspout can seem. Since far back in human history, these spouts have been viewed with awe and fear. In the Arabian Nights, for example, a waterspout is described as being a demon: “The sea became troubled before them, and there arose from it a black pillar ascending towards the sky, and approaching the meadow, and behold it was a Jinn of gigantic stature.”

It was only in the late 19th century that serious interest in the phenomenon was sparked after a particularly large spout appeared off the coast of Massachusetts. More recently, scientists have tried to measure the wind speed of waterspouts, now estimated to blow at anywhere between 15 and 85 meters per second (49 and 279 feet per second). That’s about equivalent to a weak land tornado, but it’s still strong enough to do some damage. The ancients were right to be cautious.

Pictured here, we see the calm following the storm. “Suddenly [the] umbilical connection between sea and sky split up and [the waterspout] disappeared!” says Duka. “At the same moment, the heavy rain started, so sweltering and humid that we [could] hardly breathe climbing up to the village.”


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