ナショナルジオグラフィックさんのインスタグラム写真 - (ナショナルジオグラフィックInstagram)「Photo by Stephen Alvarez @salvarezphoto | Puerto Natales, Chile: After three glorious days in the Patagonian fjords, I awoke to this dramatic sunrise. Lenticular clouds like these are formed in the troposphere when rivers of air rise above a surface obstruction. The successive turbulence causes large standing waves of moist air to form striated clouds. They are often the harbinger of rain or snow to come. True to form, the rain started just 20 minutes after sunrise ended. Shot on assignment for @natgeotravel for more images like this from around the world follow me @salvarezphoto. #lenticular #patagonia」4月3日 21時04分