The Causes and Dangers of Yellow Snow

The Causes and Dangers of Yellow Snow Yellow snow is the topic of many a winter joke. Since snow in its purest form is white, yellow snow is said to be colored with yellow liquids, like animal urine. But while animal (and human)  markings  can indeed turn  snow yellow, these  arent the only cause of yellow snow. Pollen and air pollution can also lead to large  areas of snow cover that looks like lemonade. Here are the ways snow can acquire a golden hue. Blanketed in Spring Pollen One harmless reason for yellow-tinted snow is pollen. Common in spring snows when flowering trees are already in bloom, pollen can settle in the air and on snow-covered surfaces,  marring the white color of snow. If youve ever witnessed your car covered in a thick coat of yellowish-green mid-April, then you know how thick a coating of pollen can be. Its the same with spring snows. If a large enough tree is overhead above a snow bank, the golden appearance of the snow can be spread over a large area. The pollen may be harmless  unless you happen to be allergic to it. Pollution or Sand Snow can also fall from the sky with a yellow color. Yellow snow is real. You may think snow is white, but other colors of snow exist including black, red, blue, brown, and even orange snow.   Yellow snow can be caused by air pollution  as certain pollutants in the air can give snow a yellowish tinge. Air pollutants will migrate towards the poles and become incorporated into the snow as a thin film. As sunlight hits the snow, a yellow hue can appear. When snow contains particles of sand or other cloud seeds, it can be a source of yellow or golden snow. When this occurs,  the color of the condensation nuclei can actually tint the ice crystals yellow even as it falls through the sky. One example was in South Korea when snow fell in March of 2006 with a yellow tint. The cause of the yellow snow was an increased amount of sand in the snow from the deserts of Northern China. NASAs Aura satellite captured the event as weather officials warned the public of the hazards contained within the snow. Yellow dust storm warnings are popular in South Korea, but yellow snow is rarer. Yellow snows often cause concern that they come from industrial waste. An intense yellow snow fell in areas of the Russian Urals region in March 2008. Residents worried that it came from industrial or construction sites and preliminary reports said it was high in manganese, nickel, iron, chrome, zinc, copper, lead, and cadmium. However, the analysis published in Doklady Earth Sciences showed that it was due to dust swept up from the steppes and semidesert of Kazakhstan, Volgograd, and Astrakhan. Dont Eat the Yellow Snow When you see yellow snow, its best to avoid it. Regardless of what caused snow to turn yellow, its always safest to find fresh fallen, white snow whether youll be using it for snowballs, snow angels, or especially snow ice cream.