1 00:00:01,920 --> 00:00:06,480 Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey 2 00:00:06,519 --> 00:00:09,280 Speaker 1: brain Stuff, Lauren Bogle bom here with a classic episode 3 00:00:09,320 --> 00:00:12,680 Speaker 1: for you today about the strange phenomenon of red snow, 4 00:00:13,240 --> 00:00:18,200 Speaker 1: also called watermelon snow, pink snow, or blood snow. This 5 00:00:18,320 --> 00:00:21,520 Speaker 1: is a phenomenon where snow appears pink to red in 6 00:00:21,760 --> 00:00:25,120 Speaker 1: streaks and patches due to the growth of a species 7 00:00:25,160 --> 00:00:29,760 Speaker 1: of algae, and aside from being visually striking, it's actually 8 00:00:29,760 --> 00:00:35,680 Speaker 1: fairly concerning. Hey brain Stuff, Lauren Bogle bomb here. Normally 9 00:00:36,040 --> 00:00:39,360 Speaker 1: snow looks white. This is because the ice crystals that 10 00:00:39,440 --> 00:00:42,280 Speaker 1: make up clusters of snow reflect and scatter every color 11 00:00:42,320 --> 00:00:46,000 Speaker 1: frequency in the visible light spectrum. So when sunlight bounces 12 00:00:46,000 --> 00:00:48,400 Speaker 1: off of a snow bank, all those colors blend together, 13 00:00:48,600 --> 00:00:52,040 Speaker 1: giving the snow a white appearance, or at least that's 14 00:00:52,080 --> 00:00:55,640 Speaker 1: what usually happens. Every so often, though mother Nature throws 15 00:00:55,680 --> 00:00:58,320 Speaker 1: us a curveball with a blanket of non white snow. 16 00:00:59,320 --> 00:01:01,480 Speaker 1: Plenty of the ld Or was a Roman naturalist who 17 00:01:01,520 --> 00:01:04,880 Speaker 1: lived from twenty three to seventy nine. In one of 18 00:01:04,920 --> 00:01:07,880 Speaker 1: his books, he wrote about red tinted snow, which ancient 19 00:01:07,920 --> 00:01:12,039 Speaker 1: travelers sometimes encountered. His hypothesis was that snow changes color 20 00:01:12,080 --> 00:01:14,520 Speaker 1: as time goes by, like a rusting piece of iron 21 00:01:14,920 --> 00:01:19,800 Speaker 1: snow itself. Plenty wrote Reddens with old age, and reports 22 00:01:19,800 --> 00:01:22,080 Speaker 1: of crimson colored snow kept pouring in over the next 23 00:01:22,120 --> 00:01:25,000 Speaker 1: to millennia. To figure out what's really going on, we 24 00:01:25,040 --> 00:01:28,800 Speaker 1: spoke via email with climate scientist Randall's Serveny. He reports 25 00:01:29,120 --> 00:01:31,479 Speaker 1: people in the dark and Middle Ages were often freaked 26 00:01:31,480 --> 00:01:34,880 Speaker 1: out by it. A professor at Arizona State University, Serveny 27 00:01:34,959 --> 00:01:37,640 Speaker 1: dedicated an entire book to weird weather stories in two 28 00:01:37,680 --> 00:01:41,000 Speaker 1: thousand five, titled Freaks of the Storm. It includes a 29 00:01:41,000 --> 00:01:44,839 Speaker 1: passage on red snow. As Serveny points out, there Charles 30 00:01:44,920 --> 00:01:47,520 Speaker 1: Darwin himself once came across white snow in the Andes 31 00:01:47,520 --> 00:01:50,800 Speaker 1: Mountains that turned blood red as it thawed. Another important 32 00:01:50,800 --> 00:01:53,960 Speaker 1: figure who witnessed the tinted precipitation was Sir John Ross, 33 00:01:54,000 --> 00:01:57,760 Speaker 1: a British naval officer and Arctic explorer. A reddish or 34 00:01:57,800 --> 00:02:00,880 Speaker 1: pinkish snow isn't just a historical curiosit city it's still 35 00:02:00,920 --> 00:02:04,800 Speaker 1: being observed. In February, for instance, a puddle of red 36 00:02:04,840 --> 00:02:08,079 Speaker 1: water that turned out to be melted vermillion snow was 37 00:02:08,120 --> 00:02:12,720 Speaker 1: found in Glacier National Park, So what's the mechanism behind this? 38 00:02:13,360 --> 00:02:16,400 Speaker 1: In some cases, scarlet dust may be a contributing factor. 39 00:02:17,000 --> 00:02:20,200 Speaker 1: Servini said. Many of the historic blood snows of Europe 40 00:02:20,200 --> 00:02:23,519 Speaker 1: are associated with moisture mixing with red Saharan dust that's 41 00:02:23,560 --> 00:02:26,640 Speaker 1: blown northward into Europe, which then falls out as either 42 00:02:26,720 --> 00:02:29,959 Speaker 1: red rain or snow. But it turns out that more 43 00:02:30,000 --> 00:02:33,079 Speaker 1: often than not, red snow is the product of algae, 44 00:02:33,600 --> 00:02:36,840 Speaker 1: and as scientists have learned recently, the stuff is also 45 00:02:36,919 --> 00:02:40,639 Speaker 1: contributing to climate change. We've known for some time now 46 00:02:40,680 --> 00:02:43,280 Speaker 1: that red or pink snow is generally caused by select 47 00:02:43,360 --> 00:02:47,720 Speaker 1: types of green algae, including these species Clematomonas novellis. These 48 00:02:47,800 --> 00:02:50,880 Speaker 1: life forms live in high altitude snow fields around the world. 49 00:02:51,280 --> 00:02:54,200 Speaker 1: Although they're technically green in color, the algae produce a 50 00:02:54,240 --> 00:02:57,560 Speaker 1: red pigment during the warm seasons. Doing so helps protect 51 00:02:57,600 --> 00:03:01,359 Speaker 1: the organisms from excessive solar radiation. We also spoke with 52 00:03:01,400 --> 00:03:05,040 Speaker 1: biologist Arwin Edwards, a research fellow at eberyest With University 53 00:03:05,080 --> 00:03:08,000 Speaker 1: in Wales. He said, I think of the red pigment 54 00:03:08,120 --> 00:03:11,160 Speaker 1: as a sunscreen. He explained the life cycle of this 55 00:03:11,320 --> 00:03:14,800 Speaker 1: and related types of algae. During the winter, the organisms 56 00:03:14,840 --> 00:03:17,639 Speaker 1: go dormant. Once spring arrives, they make their way toward 57 00:03:17,720 --> 00:03:20,280 Speaker 1: the surface of the snow and then bloom. But in 58 00:03:20,360 --> 00:03:23,040 Speaker 1: order to grow, the life forms need liquid water in 59 00:03:23,080 --> 00:03:26,240 Speaker 1: the form of wet snow in order to photosynthesize. This 60 00:03:26,360 --> 00:03:28,639 Speaker 1: is another reason why the red pigment is so useful. 61 00:03:29,560 --> 00:03:32,600 Speaker 1: Dark colored objects absorb more heat than light colored ones. 62 00:03:33,120 --> 00:03:36,200 Speaker 1: In snowy field where clematomotis is present, you'll find dense 63 00:03:36,200 --> 00:03:39,920 Speaker 1: communities of the microorganisms. A single millimeter that's point zero 64 00:03:40,000 --> 00:03:43,120 Speaker 1: three inches of snow can contain five hundred thousand of 65 00:03:43,120 --> 00:03:45,440 Speaker 1: these life forms. So in a large cluster of the 66 00:03:45,440 --> 00:03:48,720 Speaker 1: algae starts to release red pigment and mass, they darken 67 00:03:48,760 --> 00:03:51,200 Speaker 1: the snow they're living in. As a result, the snow 68 00:03:51,240 --> 00:03:54,640 Speaker 1: itself adopts a pinkish look. It also begins to melt. 69 00:03:55,840 --> 00:03:59,640 Speaker 1: So is this a cause for concern? In twice sixteen, 70 00:03:59,760 --> 00:04:02,600 Speaker 1: each tonal Nature published a report written under the leadership 71 00:04:02,600 --> 00:04:06,000 Speaker 1: of Stephanie Lutts, then a scientist at the University of Leeds. 72 00:04:06,120 --> 00:04:08,840 Speaker 1: Edwards was one of her co authors. After looking at 73 00:04:08,880 --> 00:04:12,360 Speaker 1: forty samples of the scarlet material from glaciers in Iceland, Norway, 74 00:04:12,480 --> 00:04:17,520 Speaker 1: Greenland and Sweden, the researchers reached a harrowing conclusion. Edwards said, 75 00:04:17,880 --> 00:04:20,000 Speaker 1: our paper is one of the first of several which 76 00:04:20,000 --> 00:04:23,760 Speaker 1: have identified a five to fiftcent acceleration of glacier melting 77 00:04:23,839 --> 00:04:26,679 Speaker 1: rates as a result of algae on the glacier surface, 78 00:04:27,000 --> 00:04:31,640 Speaker 1: a biological darkening effect. Put another way, glacial snow melts 79 00:04:31,760 --> 00:04:35,280 Speaker 1: five to fifteen percent more rapidly when Clementomonus or similar 80 00:04:35,279 --> 00:04:38,360 Speaker 1: types of algae are present, and that's not good news. 81 00:04:39,400 --> 00:04:43,360 Speaker 1: University of Bristol glaciologist Alejandra Anisio was a co author 82 00:04:43,440 --> 00:04:47,000 Speaker 1: on that Nature paper. Summing up the problem in an 83 00:04:47,000 --> 00:04:50,960 Speaker 1: email exchange, he said, basically, because of the darker coloration 84 00:04:51,000 --> 00:04:53,400 Speaker 1: of snow with the presence of the algae, the snow 85 00:04:53,440 --> 00:04:56,760 Speaker 1: absorbs more of the solar radiation, which increases pretension of 86 00:04:56,839 --> 00:04:59,760 Speaker 1: heat and melting of the snow. The process is not 87 00:04:59,839 --> 00:05:02,360 Speaker 1: in significant and must be taken into account if we 88 00:05:02,400 --> 00:05:05,160 Speaker 1: want to understand how fast glaciers and ice sheets will 89 00:05:05,160 --> 00:05:08,719 Speaker 1: melt with global warming. Also, there may be a self 90 00:05:08,720 --> 00:05:12,279 Speaker 1: perpetuating feedback loop at work here. The red tinted algae 91 00:05:12,320 --> 00:05:14,719 Speaker 1: melts snow, which enables more of the algae to grow, 92 00:05:14,920 --> 00:05:18,240 Speaker 1: which leads to even more melted snow and so on. 93 00:05:19,160 --> 00:05:21,760 Speaker 1: But let's shift gears for a moment and talk about 94 00:05:21,760 --> 00:05:25,760 Speaker 1: one of the red snow's weirdest qualities. It's scent. People 95 00:05:25,760 --> 00:05:28,680 Speaker 1: who come across the algae laden snow sometimes report that 96 00:05:28,760 --> 00:05:32,159 Speaker 1: it has a sweet, watermelon like scent. For the record, 97 00:05:32,279 --> 00:05:35,080 Speaker 1: Edward says he's never detected the odor himself, but that 98 00:05:35,160 --> 00:05:38,640 Speaker 1: it's probably the byproduct of those red pigments. Some popular 99 00:05:38,680 --> 00:05:41,559 Speaker 1: science writers have also advised against eating red snow because 100 00:05:41,560 --> 00:05:44,880 Speaker 1: it has been reported to cause gastric problems, perhaps due 101 00:05:44,920 --> 00:05:49,080 Speaker 1: to the algae other decaying material or mineral dusts and 102 00:05:49,240 --> 00:05:52,680 Speaker 1: snow can come in other colors as well. In January eighteen, 103 00:05:52,920 --> 00:05:56,480 Speaker 1: Central Kazakhstan received a layer of black tinted snow. This 104 00:05:56,600 --> 00:05:59,640 Speaker 1: may have been the result of industrial pollution. Additionally, there 105 00:05:59,680 --> 00:06:03,120 Speaker 1: are some types of algae that create yellowish snow. Of course, 106 00:06:03,160 --> 00:06:05,440 Speaker 1: as any third grader or dog owner can tell you, 107 00:06:05,720 --> 00:06:14,160 Speaker 1: that's not the only way to get yellow snow. Today's 108 00:06:14,200 --> 00:06:17,120 Speaker 1: episode is based on the article the Amazing and Alarming 109 00:06:17,279 --> 00:06:20,159 Speaker 1: science behind red Snow on how stuff Works dot com, 110 00:06:20,240 --> 00:06:23,440 Speaker 1: written by Mark Mancini. Brainstuffs production of My Heart Radio 111 00:06:23,480 --> 00:06:25,440 Speaker 1: in partnership with how Stuff Works dot com and it's 112 00:06:25,440 --> 00:06:28,360 Speaker 1: produced by Tyler Clang. Four more podcasts from My Heart 113 00:06:28,440 --> 00:06:31,520 Speaker 1: Radio visit the heart Radio app, Apple Podcasts, or wherever 114 00:06:31,560 --> 00:06:32,920 Speaker 1: you listen to your favorite shows.