[自然百科] 「噴火群山」飛碟雲大觀

Evidence of an alien invasion? No - the rare phenomenon of eerily beautiful lenticular clouds captured by a Russian photographer

Russian photographer Denis Budkov, 33, captured formations the over the Kamchatka Peninsula in Russia
The rare phenomenon occurs when strong winds are blocked by large geographical features such as mountains
The clouds are often mistaken for flying saucers or cover for UFOS because of their unusual shape

Hovering high above the mountains these unusual, saucer-like white masses resemble a creature or vehicle from another world - but they are in fact clouds.

The natural phenomenon, known as a lenticular clouds, tend to form at high altitudes, such as above mountains.

Russian photographer Denis Bukhov captured the rare phenomenon of lenticular clouds over the Kamchatka Peninsula in Russia. Resembling flying saucers, they form when the air temperature drops and moisture droplets are pushed up a steep slope by high winds

The lens-shaped formations are scientifically known as 'altocumulus lenticularis' and are the result of moist air that has condensed at a high altitude.

They are formed when the air temperature drops and moisture droplets are pushed up a steep slope by high winds.

This unique atmospheric condition creates the interesting lens-shaped form that defines a lenticular cloud.

Mountains act as natural barriers forcing clouds to condense quickly as they are pushed to cooler altitudes. This is why a large or particularly tall mountain range will experience a moist climate on one side but an arid one on the other.

Denis said that it is possible to walk to the top of a volcano, find the Pacific Ocean by following the mountain rivers and see the first sunrise over all of Russia

The lenticular cloud pattern depends upon wind speed and the shape of the mountains. A constant wind may produce clouds which are stable and remain virtually stationary, as if hovering, in the sky for hours

HOW DO LENTICULAR CLOUDS FORM?

Lenticular clouds form when a tall geographic feature, such as the the top of a mountain, interrupts a strong upward-flowing wind.[

The blocked airflow creates a 'wind wave' pattern in the atmosphere on the downwind side of the mountain.

Just as a rock in a stream will form ripples downstream, a similar effect occurs in the air – with the clouds forming at the peaks of the waves.

The impressive series of pictures taken by photographer, Denis Budkov, 33, show formations over Klyuchevskaya Sopka, the highest mountain of the Kamchatka Peninsula in Russia.

As a keen photographer, Denis said he loved nothing more than to capture the natural beauty of his home land of Kamchatka.

He said: 'These clouds are very special as they do not move, they stay in one place and it's only their shape that changes.

'There needs to be at least two factors for these clouds to appear, a very strong wind and a very high object, so Klyuchevskaya Sopka is a perfect place to find lenticular clouds.

'Kamchatka is a very special and beautiful land.

'With every new day I seem to discover more areas of natural beauty that I didn't even know existed.
'Iwas born and raised in Kamchatka, the so called 'land of fire breathingmountains' and there is nowhere else like it on Earth.

You can walk to the top of a volcano, find the Pacific Ocean by following the mountain rivers and see the first sunrise over all of Russia.'

As a keen photographer, Denis said he loved nothing more than to capture the natural beauty of his home land of Kamchatka. He said: 'These clouds are very special as they do not move, they stay in one place and it's only their shape that changes'

Just as a rock in a stream will form ripples downstream, a similar effect occurs in the air with the lenticular clouds forming at the peaks of the air 'waves'

Sometimes a phenomenon known as irisation occurs along the edge of lenticular clouds, which causes them to glow an eery red. This adds to the disturbing atmosphere evoked by the oddly shaped clouds

比飛碟更詭異　「噴火群山」飛碟雲大觀

俄羅斯堪察加半島上的有一座名叫克留契夫斯卡亞(Klyuchevskaya Sopka)的活火山，它是該半島上最高的山峰。也是當地著名景觀。它有名的原因之一，是會出現一種奇怪的自然現象，叫「飛碟雲」。

33歲的俄羅斯攝影師巴德科夫(Denis Budkov)，最喜愛的攝影主題，就是拍下家鄉堪察加半島的自然美；其中包括克留契夫斯卡火山的「飛碟雲」。

巴德科夫說：「這些雲很特別。它們不會移動，他們總是待在同一個地方，只是改變本身的形狀。飛碟雲的出現需要至少兩個因素：很強的風、很高的地物。克留契夫斯卡亞火山正是這樣的一個完美代表。堪察加半島是一塊非常特殊和美麗的土地。幾乎每一天我都發現以前從沒看過的自然美。這塊被稱為擁有『噴火群山』的大地，在地球上是獨一無二的。」

「飛碟雲」又名「凸透鏡雲」 (Lenticular clouds)，它是由漂浮在空中的小水滴組成的。通常是當崎嶇地表上空的潮濕空氣，以高速流過山頂時就會造成這種目然現象，它的正式名稱是「莢狀雲」。有時候會被誤認為不明飛行物，所以又暱稱為「飛碟雲」。

簡單來說，「飛碟雲」的成因多是由於空氣流經山丘時，受地形作用影響，空氣被抬升至大氣上方。氣流在山丘後方以波浪狀推進，在波峰上空氣中的水份凝結成雲，經過一段時間的積聚，便形成一層層像由大小不同的頭盔堆疊而成的「莢狀雲」。

另一種產生「飛碟雲」的原因，是因為大氣中局部上升氣流和下降氣流匯合而成所致。上升氣流絕熱冷卻形成的雲，遇到上方下降氣流的阻擋時，雲體不僅不能繼續向上升展，且其邊緣部分因下降氣流增溫的結果，有蒸發變薄現象，故呈莢狀，氣流越山時，在山後引起空氣的波動，也可形成「莢狀雲」。